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Grid-tie Transformerless Solar Inverter

M88H
Operation and Installation Manual

www.deltaww.com
Table of Contents
1 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 08
1.1 Information of the Inverter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 08
1.1.1 Disclaimer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 08
1.1.2 Target Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 08
1.2 General Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 09
1.2.1 Condition of Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 09
1.2.2 Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.1 Valid Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.2 Product Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.1 Mechanical Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.2 Electrical Installation for AC Cabling . . . . . . . . . . . . . . . . . . . . . . . . 22
3.2.1 Required Protective Devices and AC Cabling Installation for M88H_121 . . . . . . 23
3.2.2 Required Protective Devices and AC Cabling Installation for M88H_122 . . . . . . 25
3.3 Electrical Installation for DC Cabling . . . . . . . . . . . . . . . . . . . . . . . 28
3.3.1 DC Cabling Installation for M88H_121 . . . . . . . . . . . . . . . . . . . . . . . 29
3.3.2 DC Cabling Installation for M88H_122 . . . . . . . . . . . . . . . . . . . . . . . 31
3.4 Communication Module Connections . . . . . . . . . . . . . . . . . . . . . . . 33
3.4.1 RS-485 Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
3.4.2 EPO Function & Digital Input . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
3.4.3 Dry Contact connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
4 Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
4.1 Display Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
4.2 First startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
4.2.1 Home Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
4.2.2 Power Meter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
4.2.3 Energy Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.2.4 Event Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.2.5 Inverter Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
4.2.6 General Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
4.2.7 Install Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
4.2.8 Inverter ID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
4.2.9 Insulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
4.2.10 Dry Contact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

3
5 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
5.1 Replace Surge Protection Device (SPD) . . . . . . . . . . . . . . . . . . . . . . 46
5.2 Smart Fans Replacement and Filters Cleaning . . . . . . . . . . . . . . . . . . 49
5.3 De-Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
5.3.1 Disassemble the Wiring box compartment . . . . . . . . . . . . . . . . . . . . . 55
6 Error message and Trouble Shooting . . . . . . . . . . . . . . . . . . . . . . . . 58
7 Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

4
Figure
Figure 2-1 : Components of M88H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Figure 2-2 : Overview of M88 series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Figure 2-3 : Rating labels of M88H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Figure 2-4 : Wiring box layout of M88H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Figure 3-1 : Mounting bracket dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Figure 3-2 : Required position for at least 8 screws . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 3-3 : Prohibited position for screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 3-4 : Permitted mounting positions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 3-5 : Prohibited mounting positions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 3-6 : Required mounting clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Figure 3-7 : Specification of fixing WB for wall-mounting installation . . . . . . . . . . . . . . . 21
Figure 3-8 : Stripping cables for M88H_121 AC terminal . . . . . . . . . . . . . . . . . . . . . 23
Figure 3-9 : Location for M88H_121 AC terminal . . . . . . . . . . . . . . . . . . . . . . . . . 24
Figure 3-10 : Stripping cables for M88H_122 AC terminal . . . . . . . . . . . . . . . . . . . . . 25
Figure 3-11 : Location for M88H_122 AC terminal . . . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 3-12 : Guideline for aluminum conductor . . . . . . . . . . . . . . . . . . . . . . . . . 27
Figure 3-13 : Wiring Box layout for M88H_121 . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Figure 3-14 : Location for DC terminals for M88H_121 . . . . . . . . . . . . . . . . . . . . . . 30
Figure 3-15 : Wiring Box layout for M88H_122 . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Figure 3-16 : Location for DC terminals for M88H_122 . . . . . . . . . . . . . . . . . . . . . . 31
Figure 3-17 : Guideline for aluminum conductor . . . . . . . . . . . . . . . . . . . . . . . . . 32
Figure 3-18 : Communication Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Figure 3-19 : Multiinverter connection illustration . . . . . . . . . . . . . . . . . . . . . . . . 34
Figure 3-20 : EPO function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Figure 3-21 : Dry Contact connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Figure 4-1 : Panel indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Figure 4-2 : Country, language and ID settings for first startup . . . . . . . . . . . . . . . . . 39
Figure 4-3 : Home page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Figure 4-4 : Power meter page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Figure 4-5 : Energy log Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Figure 4-6 : Event log Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Figure 4-7 : Inverter information page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Figure 4-8 : General settings page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Figure 4-9 : Install settings page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Figure 4-10 : Inverter ID page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Figure 4-11 : Insulation page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Figure 4-12 : Dry Contact page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

5
Figure 5-1 : AC and DC SPD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Figure 5-2 : Remove front cover of wiring box compartment . . . . . . . . . . . . . . . . . . . 47
Figure 5-3 : The alarms indicate AC and DC SPD Fail . . . . . . . . . . . . . . . . . . . . . . 48
Figure 5-4 : Pull out the connectors and remove the screws as shown in arrows . . . . . . . . 48
Figure 5-5 : Smart fans location on Power Module compartment . . . . . . . . . . . . . . . . 49
Figure 5-6 : Smart fan location on WB (M88H_122 only) . . . . . . . . . . . . . . . . . . . . 49
Figure 5-7 : 12" Potting fan kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Figure 5-8 : Disassembling fan inside the wiring box compartment (M88H_122 only) . . . . . . . 51
Figure 5-9 : Disassembling fans inside the power module compartment (showing one side only) . . . 52
Figure 5-10 : Removal of filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Figure 5-11 : The ON/OFF positions of DC Switches (M88H_122 only) . . . . . . . . . . . . . 55
Figure 5-12 : Remove AC, DC, and communication cables and then unscrew 6 screws . . . . . 56
Figure 5-13 : Remove 8 screws and then separate WB from PM . . . . . . . . . . . . . . . . 57

6
Table
Table 2-1 : Packing list of M88H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Table 2-2 : Rating label explanation of M88H . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Table 2-3 : Wiring box layout description of M88H . . . . . . . . . . . . . . . . . . . . . . . . 16
Table 3-1 : Definition of RS-485 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Table 3-2 : Terminal resister setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Table 3-3 : Definition of digital input & EPO function . . . . . . . . . . . . . . . . . . . . . . . 35
Table 4-1 : LED indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Table 4-2 : Dry Contact Trigger Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Table 5-1 : SPD Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Table 6-1 : Error Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Table 6-2 : Warning Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Table 6-3 : Fault Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Table 7-1 : Specifications for M88H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

7
Safety

1 Safety
1.1 Information of the Inverter

1.1.1 Disclaimer
Copyright – DELTA ELECTRONICS, INC. - All rights reserved.
This manual accompanies our product for use by the end users. The technical
instructions and illustrations contained in this manual are to be treated as
confidential and no part may be reproduced without the prior written permission
of DELTA ELECTRONICS, INC. Service engineers and end users may not
divulge the information contained herein or use this manual for purpose other
than those strictly connected with correct use of the product. All information and
specifications are subject to change without notice.
DELTA ELECTRONICS, INC. shall have no obligation to both personal injury
and property damage hereinafter with respect to any actions -- (a) the product
has been installed and repaired improperly; (b) the product has been misuse
without following the instructions on this user manual; (c) the product has failed
due to incorrect unpacking.

1.1.2 Target Group

This user manual of the solar inverter is prepared for a person who is well-trained
for installing, commissioning, using, and doing maintenance. The well-trained
person must have the following basic and advanced skills:

• The fundamentals of electricity, wiring, electrical components and electrical

schematic symbols.
• Knowledge of how a solar inverter works and is operated.
• Training in the installation and commissioning of electrical devices and installations.
• Training in how to deal with the dangers and risks associated with installing
and using electrical devices and installations.
• Compliance with this manual and all safety information.

Please read the user manual before working on the product.

8
 Safety

1.2 General Safety

IMPORTANT SAFETY INSTRUCTIONS : SAVE THESE INSTRUCTIONS !

- Please read these instructions carefully and save them for later use.

To prevent any personal injury and any property damage, also ensure long-term
operation of the solar inverter, you must read this section carefully and review all
the safety instructions at all times before using this inverter.
This user manual provides important instructions for Delta grid-tie transformerless
solar inverter. The product is designed, tested, verified, and certified according
to international safety requirements, regulations, and standards but precautions
must be observed when installing and operating the product.

ATTENTION : NO GALVANIC ISOLATION

- There is no accessory such as a transformer along with our product and

therefore the product has no galvanic isolation.
External transformer should be installed between AC output of inverter and Grid.
Please do not connect grounded Photovoltaic modules to the product.
If you connect grounded Photovoltaic modules to the product, the error message
INSULATION (E34) shows up.
- It is prohibited to connect the L1, L2, L3, and N to the ground.

1.2.1 Condition of Use

The M88H is a transformerless solar inverter with two MPP trackers which
converts the variable direct current of the solar array into a utility frequency
grid-compliant three-phase current and feeds it into the utility grid.
The Photovoltaic modules used must be compatible with the inverter.
Photovoltaic modules with a high parasitic capacitance to ground may only be
applied if the capacitive coupling does not exceed 8μF.

The inverter must only be operated in countries for which it is approved by Delta
and the grid operator.

9
Safety

1.2.2 Symbols
This section describes the definition of the symbols in this manual.
In order to prevent both personal injury and property damage, and to ensure
long-term operation of the product, please read this section carefully and follow
all the safety instructions while you use the product.

DANGER!

- This warning indicates an immediate hazard which will lead to death or serious
injury may occur.

WARNING !

- This warning indicates a possible hazard which may lead to death or serious
injury may occur.

CAUTION !

- This warning indicates a possible hazard which may lead to minor injury
may happen.

ATTENTION

- This warning indicates a possible damage to property and the environment

might happen.

10
 Safety

INFORMATION

- Additional information is indicated by an exclamation mark enclosed by double

circle. This means the following section contains important information and
user should follow the instruction to prevent any hazards.

DANGER : ELECTRICAL HARZARD!!

- This warning indicates an immediate electrical hazard which will lead

to death or s erious injury may occur.

CAUTION : HOT SURFACES, DO NOT TOUCH!

- This warning indicates be careful of hot surfaces when operating the product.
- Do not perform any task until the product cool down sufficiently.

- Wait for a prescribed amount of time before engaging in the indicated action.
- Patientez le délai requis avant d’entreprendre l’action indiquée

- Equipment grounding conductor (PE)

- (PE) Équipement conducteur de terre

11
Introduction

2 Introduction
The M88H is designed to enable the highest levels of efficiency and provide
longest operating life of photovoltaic inverter by state-of-the-art high-frequency
and low EMI technology. It is suitable for outdoor use.

ATTENTION : NO GALVANIC ISOLATION

- There is no accessory such as a transformer along with our product and

therefore the product has no galvanic isolation.
External transformer should be installed between AC output of inverter and Grid.
Please do not connect grounded Photovoltaic modules to the product.
If you connect grounded Photovoltaic modules to the product, the error message
INSULATION (E34) shows up.
- It is prohibited to connect the L1, L2, L3, and N to the ground.

2.1 Valid Model

The user manual is valid for the following device types :

• M88H_121
• M88H_122

This user manual must be followed during installation, operation, and maintenance.

The M88 Series have 2 models as shown in Figure 2-2. Delta reserves the right
to make modifications to the content and technical data in this user manual
without prior notice.

12
 Introduction

2.2 Product Overview

The components of M88H is shown as Figure 2-1.

① ② ③ ④

Figure 2-1 : Components of M88H

M88H

Object Qty Description

1 Delta Solar Inverter 1 pc Solar inverter

Important instructions for solar inverter

2 User Manual 1 pc Safety instructions should be followed
during installation and maintenance

3 Screw 5 pcs Inverter with wall mount screws

Wall mounting bracket

4 Mounting Bracket 1 pc
(indude packing for wiring box)

Table 2-1 : Packing list of M88H

13
Introduction

M88H_121 Air Outlets /

Smart Fans

LCD / LED Display

and Buttons

Gland for AC Wiring

Communication Rating Label

Connetions
Gland for DC Wiring
Air Inlets

M88H_122 Air Outlets /

Smart Fans

LCD / LED Display

and Buttons

Gland for AC Wiring

Communication Rating Label

Connetions
Air Inlets
MC4 type DC connector DC Switch
18 pairs

Figure 2-2 : Overview of M88 series

14
 Introduction

The following Figure 2-3 shows the rating labels of M88H along with these
labels explains the definition of the specific mark.
Figure 2-4 illustrates the layout of wiring box of M88H and the table (Table 2-3)
along with this layout describes the detail of each area.
This compartment includes inverter inputs (DC), outputs (AC), surge protection
device (SPD), fuse holder, DC switch and the communication connection such
as RS-485.

Figure 2-3 : Rating labels of M88H

Symbol Definition
Danger to life through electric shock
Potentially fatal voltage is applied to the inverter during operation.
This voltage persists even 100 seconds after disconnection of the power supply.
Never open the inverter. The inverter contains no components that must be
100 seconds maintained or repaired by the operatoror installer.
Opening the housing will void the warranty.

Before working with the inverter, you must read the supplied
manual and follow the instructions contained therein.

This inverter is not separated from the grid with a transformer.

The housing of the inverter must be grounded if this is required

by local regulations.

WEEE marking
The inverter must not be disposed of as standard household
waste, but in accordance with the applicable electronic waste
disposal regulations of your country or region.

Table 2-2 : Rating label explanation of M88H

15
Introduction

M88H_121
⑫ ⑬

⑤
IN 1

①
IN 2 ②
⑥

④ ⑩ ⑯

M88H_122 ⑫ ⑭ ⑬

⑩ ⑪

IN 1 IN 2 ⑨
⑯
⑩
⑦ ⑪
⑧

⑲
⑮
①

Figure 2-4 : Wiring box layout of M88H

NO. Component NO. Component NO. Component

1 Cable gland for AC 7 Fuse holder type DC IN1 13 Internal DC terminal

2 Cable gland for DC 8 Fuse holder type DC IN2 14 Wiring box fan

3 95mm 2 AC terminal 9 DC switch 15 MC4 connector

4 120mm2 AC terminal 10 Type II AC SPD 16 Grounding bar

5 120mm2 DC terminal for IN 1 11 Type II DC SPD

6 120mm2 DC terminal for IN 2 12 Internal AC terminal

Table 2-3 : Wiring box layout description of M88H

16
 Installation

3 Installation
CAUTION !

- The unit should not be installed in direct sunlight.

WARNING !

- Do not install the unit near or on flammable surfaces.

- Please mount the unit tightly on a solid / smooth surface.

The chapter contains instructions for (1) Mechanical installation; (2) Electrical
Installation; (3) Communication setup.

3.1 Mechanical Installation

This unit is designed to be wall-mounted. Please ensure that the installation is
perpendicular to the floor and the AC and DC terminal are at the bottom position.
Please follow the instruction as shown from Figure 3-1 through 3-3. First, fix the
wall mounting bracket on a solid support surface. Second, please mount the
inverter on the bracket securely. Note that Figure 3-1 through 3-7 should be
followed.
To mount the inverter on the wall, please follow the procedure :

1. Screw the wall mounting bracket on the wall with at least 8 M8 Phillips head
screws. Please refer to Figure 3-1 and 3-2 for correct installation.
2. Hang the inverter on the wall mounting bracket.
3. There are two ways for fixing the wall mounting bracket as shown in Figure 3-2.
4. Figure 3-3 through 3-7 describes correct mounting installation.
5. Figure 3-7 shows the installation detail for fixing the wiring box.

CAUTION !

- Please fix at least 8 M8 Phillips head screws for the wall mounting bracket.
- The bracket shipped with the unit is specially designed and should be the only
mounting device for the mechanical installation.

17
Installation

Figure 3-1 : Mounting bracket dimensions

18
 Installation

Necessary for vertical fixing Necessary for horizontal fixing

Figure 3-2 : Required position for at least 8 screws

Figure 3-3 : Prohibited position for screws

19
Installation

90

Figure 3-4 : Permitted mounting positions

> 75

Figure 3-5 : Prohibited mounting positions

O : Permitted / X : Prohibited

20
 Installation

Wall
> 33cm
> 60cm

> 50cm > 80cm

> 5cm

Inverter #1 Inverter #2

> 50cm

Figure 3-6 : Required mounting clearances

CAUTION !

- Please follow the instructions above such as permitted positions and

permitted mounting clearances for the correct installation.

After installing the unit, fix the wiring box with 4 screws.
The torque of the screw: 45 kgf.cm

Figure 3-7 : Specification of fixing WB for wall-mounting installation

21
Installation

3.2 Electrical Installation for AC Cabling

DANGER : ELECTRICAL HARZARD!!

- Any AC electric power connected to the inverter during cabling is prohibited.

WARNING !

- Code compliance is the installer's responsibility.

- Inverter warranty void if the DC input voltage exceeds 1000 Vdc.

CAUTION : INVERTER AND EQUIPMENT DAMAGE MAY OCCUR !

- Please make sure to choose the proper size for AC cable.
- Installation for AC terminal must meet the local electrical code.
- Failed to follow the instructions may damage AC cable.

ATTENTION

- This inverter may be damaged due to moisture or dust intrusion.

Please do not open the lid of the inverter.

22
 Installation

3.2.1 Required Protective Devices and AC Cabling

Installation for M88H_121
It is recommended to install an upstream circuit breaker between AC side and
inverter side for over current protection.

Model Upstream circuit breaker

M88H ≧125A

Please follow the following steps for assembling the AC terminal (M88H_121) :
• It is important to choose the proper size for AC cable.
• Strip off all wires for 40 mm.
• The cross-sectional area for each internal cable is 1AWG ~ 250kcmil.

Conductor cross-section:
1AWG~250kcmil (50~120mm²)

L1

L2

L3 outer
N jacket
PE

Stripping length:
40 ~ 42mm

Figure 3-8 : Stripping cables for M88H_121 AC terminal

- It is important to choose the correct fixing screws for the photovoltaic fuseholder.
- Each individual screw with torque 26 N.m is required.

23
Installation

AC Terminal

L1

outer L2
jacket
L3

PE

135mm bending space

Cable gland for AC Torque 26N.m to fix the screw

Figure 3-9 : Location for M88H_121 AC terminal

24
 Installation

3.2.2 Required Protective Devices and AC Cabling

Installation for M88H_122
It is recommended to install an upstream circuit breaker between AC side and
inverter side for over current protection.

Model Upstream circuit breaker

M88H ≧125A

Please follow the following steps for assembling the AC terminal (M88H_122) :

• It is important to choose the proper size for AC cable.

• Strip off all wires for 24 mm.
• The cross-sectional area for each internal cable is 2~3/0 AWG.

Conductor cross-section:
2~3/0 AWG (35 ~ 95mm²)

L1

L2

L3 outer
N jacket
PE

Stripping length:
24 ~26mm

Figure 3-10 : Stripping cables for M88H_122 AC terminal

25
Installation

AC Terminal Torque 8N.m to

fix the screw

115mm bending space

PE N L1 L2 L3

Cable gland for AC

outer
jacket

Figure 3-11 : Location for M88H_122 AC terminal

Figure 3-15 illustrates the location of cable gland for AC terminal as shown above :

- It is important to choose for the fixing screws.

- Each individual screw with torque 8N.m is required
- The bending space is 115 mm which meets the safety standard.

26
 Installation

Please follow the following guideline for cabling if you use aluminum cables.

Guideline for aluminum conductor :

- The oxide layer must be removed from the surface of the stripped aluminum
conductor.
- The stripped aluminum conductor is greased with Vaseline or contact grease
with comparable properties after oxide layer removed.
- Tightened with the maximum tightening torque for the modular terminal block.
- The installation location must be kept free from humidity or aggressive
atmospheres.
- It is recommend to apply to sector-shaped single-strand conductor ;
The conductor shape must match the sector-shaped connection

90°
SE
Sector-shaped
single-strand

match the sector-shaped of the connection

Figure 3-12 : Guideline for aluminum conductor

27
Installation

3.3 Electrical Installation for DC Cabling

DANGER : ELECTRICAL HARZARD!!

- PV array converts sunlight into electric power with high DC voltage and high DC
current which can cause dangerous electrical shock hazard. Please use an
opaque material to cover the PV array before wiring or cabling.
- Please ensure the correct polarities are connected when DC cabling is applied.

WARNING !

- The risk of electric shock and fire. Only PV modules that are listed with system
voltage under 1100V are permitted for use.
- Please ensures that the DC Switch Turns "OFF" as well as the PV array
is disconnected when DC cabling is applied.

ATTENTION

- The PV Array positive or negative leads must not be connected to ground.

28
 Installation

3.3.1 DC Cabling Installation for M88H_121

Please read the following instructions for attaching DC terminals (M88H_121) :

• It is important to choose the proper size for DC cable.

• The cross-sectional area for each internal cable is 1AWG~250kcmil.

• It is important to choose the correct fixing screws.

• Each individual screw with torque 26N.m is required.
• The bending space is 135 mm which meets the safety standard.

• DC Terminals connection as seen in Figure 3-14.

ATTENTION

- The screw with torque 26N.m is required for fixing.

- The required bending space is 135 mm as the requirement states.

+
IN 1
-
+ PE
IN 2
-

Figure 3-13 : Wiring Box layout for M88H_121

29
Installation

DC Terminal

Cable gland for DC

IN1+

IN1-

PE outer
IN2+ jacket
IN2-

135mm bending space

Stripping length : 40 ~ 42mm

Conductor cross-section : 1AWG ~ 250kcmil (50 ~ 120mm²)
Torque 26N.m to fix the screw

Figure 3-14 : Location for DC terminals for M88H_121

30
 Installation

3.3.2 DC Cabling Installation for M88H_122

IN 1 IN 2

Figure 3-15 : Wiring Box layout for M88H_122

+ - + - + - + - + - + -

+ - + - + - + - + - + -

+ - + - + - + - + - + -

IN 1 IN 2

Figure 3-16 : Location for DC terminals for M88H_122

31
Installation

Please follow the following guideline for cabling if you use aluminum cables.

Guideline for aluminum conductor :

- The oxide layer must be removed from the surface of the stripped aluminum
conductor.
- The stripped aluminum conductor is greased with Vaseline or contact grease
with comparable properties after oxide layer removed.
- Tightened with the maximum tightening torque for the modular terminal block.
- The installation location must be kept free from humidity or aggressive
atmospheres.
- It is recommend to apply to sector-shaped single-strand conductor ;
The conductor shape must match the sector-shaped connection

90°
SE
Sector-shaped
single-strand

match the sector-shaped of the connection

Figure 3-17 : Guideline for aluminum conductor

32
 Installation

3.4 Communication Module Connections

The communication module of M88H provides VCC, RS-485, dry contact, EPO,
and Digital Input terminals for different use.

Dry Contact Terminal Resistor & VCC Switch

EPO*1 & VCC & RS-485

Digital Inputs*6

Figure 3-18 : Communication Module

3.4.1 RS-485 Connection

The pin definition of RS-485 is shown in the following table. Different RS-485
connection requires different set up for the terminal resistor.

• When single inverter is installed, the terminal resistor on its communication

module should be switched ON.
• When several inverters are cascaded, only the first and the last inverter’s
terminal resistors MUST be switched ON.

33
Installation

Pin Function

1 VCC (+12V)

2 GND 1 23 4 5 6
3 DATA+

4 DATA-

5 DATA+

6 DATA-

Table 3-1 : Definition of RS-485

Terminal Resistor
120Ω(1/2W)
DATA+ to DATA-

Data Format:
Baud rate: 19200 RS485/USB
Data bits: 8 or
Stop bit: 1
Parity: N/A RS485/RS232

Figure 3-19 : Multiinverter connection illustration

Switch 1 Switch 2
ON VCC ON Terminal Resistor ON
OFF VCC OFF Terminal Resistor OFF

Table 3-2 : Terminal resister setting

34
 Installation

3.4.2 EPO Function & Digital Input

Communication Module has 1 set of emergency power off function (EPO).
Users can customize EPO function in Install Settings page.

EPO & Digital Input

Figure 3-20 : EPO function

Short Inverter’s action

V1 & K0 Emergency power off (EPO)
V1 & K1 0% active power
V1 & K2 Maximum 30% rated power

V1 & K3 Maximum 60% rated power

V1 & K4 Maximum 100% rated power
V1 & K5 Reserved

V1 & K6 Reserved

Table 3-3 : Definition of digital input & EPO function

35
Installation

3.4.3 Dry Contact connection

M88H series provide 1 set of Dry Contact. The first and the second port are
used while the third port is not used. The function can be customized by users,
please refer to section 4.2.10 Dry Contact.

Dry Contact

Figure 3-21 : Dry Contact connection

36
 Commissioning

4 Commissioning
CAUTION : HOT SURFACES, DO NOT TOUCH!

- This warning indicates be careful of hot surfaces when operating the product.
- Do not perform any task until the product cool down sufficiently.

4.1 Display Introduction

M88 series include a 4x20 character type LCD display and 2 LED lights
( located on the left-hand side of the LCD ) to indicate inverter’s status as shown
in Figure 4-1. Please refer to Table 4-1 for more information about inverter’s
statuses and LED indicator.
The following section will introduce the functions that can be adjusted by users
through the LCD panel. When you are adjusting settings, LCD panel will change
the display cursor from “►” to “ ”.

Power Meter 4.2.2

Energy Log 4.2.3
Event Log 4.2.4
Inverter Information 4.2.5
General Settings 4.2.6
Install Settings 4.2.7
Inverter ID 4.2.8
Insulation 4.2.9
Dry Contact 4.2.10

37
Commissioning

ENT : Enter Menu or Confirm

LED Indicator (RED)
UP : Move UP
LED Indicator (GRN) Down : Move Down
EXIT : Exit Menu

Figure 4-1 : Panel indicator

Condition Green LED Red LED

Standby or Countdown FLASH * OFF
Power ON ON OFF
Error or Fault OFF ON
Night time (No DC) OFF OFF
Bootloader mode FLASH *
* ON 1s / OFF 1s
Table 4-1 : LED indicator

38
 Commissioning

4.2 First startup

At first startup, user has to feed in AC power and switch on the manual switch
and DC Power Switch. Inverter will start up and LCD display panel will turn on
when powered on through AC. Please set language and the correct country
(Grid Code) according to your region.
Please make sure that there is no any error, fault or warning showing on home
page. Now you can feed in DC power and wait for inverter initially self-test
about 2 minutes. If there is enough power generated from PV array, inverter
will start feeding in power to grid.

The following Figure 4-2 illustrates the display flow charts of the inverter startup.

Select Language, ENT ►India 400V ENT Are you sure to ENT
►English India 480V set country :
Deutsch Taiwan 400V XXX
Français EXIT Taiwan 480V EXIT Yes / ►No EXIT

When country setting is

XXX ENT ENT Are you sure to set
Setting ID : ID : 001
ID = 001
EXIT EXIT Yes / ►No

Figure 4-2 : Country, language and ID settings for first startup

39
Commissioning

4.2.1 Home Page

When inverter is being operated normally, the LCD will display the homepage
as shown in Figure 4-3, user can get the information about output power,
inverter status, E-today, date and time.
Press "any" key in home page will be directed to the main menu. Press EXIT at
main menu or wait 5 minutes without any operation, the display will return to
homepage.

20. Jan 2016 16 : 30 Day -Time

Inverter Status Status : On Grid
Output Power Power : 88.00 kW
Today Energy E-Today : 192 kWh

Figure 4-3 : Home page

4.2.2 Power Meter

This page displays voltage, current and power from both AC and DC side.

AC L1 L2 L3
V 480 480 480 V
I 99.9 99.9 99.9 A
P 27.7 27.7 27.7 kW

or ENT

PF : 0.95 Cap
Power : 70.35 kW
Frequency
: : 60.00 Hz
E-Today : 24 kWh

or ENT

DC DC1 DC2
V 665 702 V
I 61.0 61.3 A
P 40.5 43.0 kW

Figure 4-4 : Power meter page

40
 Commissioning

4.2.3 Energy Log

User can view the inverter’s life energy and life runtime via Energy Log page.

Energy Log
Life Energy : 642.5 MWh
Runtime : 7302 Hrs

Figure 4-5 : Energy log Page

4.2.4 Event Log

Event Log has two subpages : Error Events page and Grid Report page.
Error Events page displays all the events (Error and Fault) and it can show 30
records at a time. Grid Report page only displays the error that occurred at grid
side, and it can show 5 records at a time.

No Event
►Error Events ENT 1. 20/01/2016 15 : 30 Empty
Grid Report AC Freq High
2. 19/01/2016 09 : 30
EXIT AC Volt Low

or ENT
Press ▲,▼&ENT > 5s Yes
29. 20/01/2016 15 : 30 or ENT
AC Freq High Clear Event Logs ?
EXIT
30. 19/01/2016 09 : 30 Yes / ►No
AC Volt Low

No Event
Error Events ENT 1. 20/01/2016 15 : 30 Empty
►Grid Report No Gird
2. 19/01/2016 09 : 30
EXIT AC Volt Low

or ENT
Press ▲,▼&ENT > 5s Yes
5. 20/01/2016 15 : 30 or ENT
AC Freq High Clear Event Logs ?
EXIT
Yes / ►No

Figure 4-6 : Event log Page

41
Commissioning

4.2.5 Inverter Information

This page can helps user to recognize the inverter. First section displays serial
number, installation date, ID, and firmware version. The settings of inverter
functions are described in the following sections.

S/N : RN11179CB0
Install : 11/01/2016
DSP 1.80 Red. 1.65
Comm. 1.65 ID : 002

or ENT

Country :
Taiwan 480V
Insulation : 1200k
Baud Rate : 19200bps

or ENT

AC connection : 3P3W
Max. Power : 88000VA
Dry Cont A : Insu.
Dry Cont B : Disable

or ENT

EPO : Normal Close

► Grid Settings
Active Pwr Settings
React Pwr Settings

or ENT

► FRT Settings

Figure 4-7 : Inverter information page

4.2.6 General Settings

Users can set Language, Date & Time, and RS-485 communication baud rate
in this page.

► Language
Date & Time
Baud Rate
Test Menu

Figure 4-8 : General settings page

42
 Commissioning

4.2.7 Install Settings

CAUTION !
- The settings in Install Settings page can only be adjusted by qualified
installers or engineers. Changing these settings may result in damage
to the inverter and other equipment.

To enter Install Settings page, users have to enter correct password.

There are 3 sets of password with different permissions: user level, installer level,
and manufacturer level. The following sub-sections will introduce the setting
items in Install Settings page of user level and installer level.

► Inverter ID : 002 User Level:

Insulation - Inverter ID
Country - Insulation
Grid Settings - Country
- Dry Cont.
- PID Function
- EPO
► DC Injection - AC Connection
Dry Cont. - Max. Power
PID Function
RCMU ON Installer Level:
- Inverter ID
- Insulation
- Country
► EPO Normal Open
- Grid Settings
AC Connection 3P3W
- Dry Cont.
Anti-islanding ON
- PID Function
Max. Power 88000W
- EPO
- AC Connection
- Max. Power
► AFCI OFF
Return to Factory Manufacturer Level:
- All Settings

Figure 4-9 : Install settings page

43
Commissioning

4.2.8 Inverter ID
Inverter ID is used in RS-485 communication, for PC recognizing the inverter.
If users connect several inverters together via RS-485, each inverter must have
different ID.

► Inverter ID : 002 ENT

Insulation Setting ID :
Country ID = 002
Grid Settings
EXIT

Figure 4-10 : Inverter ID page

4.2.9 Insulation
Before connecting to grid, inverter will measure the impedance between the PV
array and PE first. M88H models provide 2 types of impedance measurement
methods (ON and OFF) and 2 impedance limits.
Installer must select the appropriate method based on PV array’s wiring.

ENT
► Mode : ON ► ON
Resistance : 100kΩ OFF

EXIT

Figure 4-11 : Insulation page

44
 Commissioning

4.2.10 Dry Contact

Users can choose the trigger condition of dry contact. There are 8 options in the
setting page: Disable, On Grid, Fan Fail, Insulation, Alarm, Error, Fault, and
Warning. Please refer to Table 4-2 for more details about these options.

Setting Dry Contact Trigger Timing

Disable No action.
On Grid Inverter is connecting to grid.

Fan Fail Fan Fail occurs.

Insulation Insulation test fail.

Alarm Any error, fault, or warning occurs.

Error Any Error occurs.

Fault Any Fault occurs.

Warning Any Warning occurs.

Table 4-2 : Dry Contact Trigger Setting

ENT ENT
DC Injection ► Dry Cont.A
. Insu. ► Disable
► Dry Cont. Dry Cont.B Disable On Grid
ENT
RCMU ON Fan Fail
EPO Normal Close EXIT Insulation
EXIT

► Alarm
Error
EXIT ENT
Fault
Warning

Figure 4-12 : Dry Contact page

45
Maintenance

5 Maintenance
Please check the unit regularly. If there are any impaired or loose parts, please contact
your solar installer. Ensure that there are no fallen objects in the path of the heat outlet.

WARNING !

- Before any maintenance, please switch AC and DC power off to avoid risk
of electrical shock.

5.1 Replace Surge Protection Device (SPD)

M88 series models have the surge protection device (SPD) at both AC and
DC side as shown in Figure 5-1. Table 5-1 summarizes the specifications of AC
and DC SPD.

Figure 5-1 : AC and DC SPD

Specification of SPD

Work voltage : 895V (AC RMS value)

1175V (DC)
Work Amp In (8/20μs) : 10kA
Rate Amp I max (8/20μs) : 20kA
Temperature : -40℃∼85℃
Manufacturers :
Sichuan Zhongguang Lightning Protection Technologies Co., Ltd

Table 5-1 : SPD Specifications

46
 Maintenance

The surge protection devices (SPD), located on both AC and DC input terminals,
are designed to protect sensitive circuit elements of the inverter from damage
caused by lightning and electrical transient surges. If you find a warning message
“AC Surge” or “DC Surge” shown on display panel, please follow the steps below
to replace the SPD.
1. Switch AC and DC power off and wait until LCD display turn off.
2. Loosen the 4 screws on the front cover of wiring box compartment.
You will see AC and DC SPD as indicated in the figure. (Figure 5-2)
3. Find out which SPD unit was damaged.
For AC SPD, “AC Surge” with show on the corner of the LCD panel. (Figure 5-3)
For DC SPD, “DC Surge” with show on the corner of the LCD panel.
4. Pull out the connector (white; 3 pins at AC side; 2 pins at DC side) and replace
a whole new SPD PCB. (Figure 5-4)
5. Reassemble the inverter. Please be careful of the waterproof seal.

DC SPD

AC SPD
M88H_121

AC SPD DC SPD

M88H_122

Figure 5-2 : Remove front cover of wiring box compartment

47
Maintenance

Figure 5-3 : The alarms indicate AC and DC SPD Fail

AC SPD

DC SPD

Figure 5-4 : Pull out the connectors and remove the screws as shown in arrows

48
 Maintenance

5.2 Smart Fans Replacement and Filters Cleaning

This section provides the instructions for smart fans replacement and filters
cleaning for M88 series models. Figure 5-5, 5-6, 5-7 illustrates the locations
of smart fans.

M88 series models have smart fans that can be categorized into two parts:
Wiring Box compartment (WB) and Power Module compartment (PM) as shown
in the overview picture (Figure 5-5). The following procedure dipicts the steps to
clean the filters.

Air Outlets
/ Smart Fans inside PM

Figure 5-5 : Smart fans location on Power Module compartment

M88H_122

Fan inside WB

Figure 5-6 : Smart fan location on WB (M88H_122 only)

49
Maintenance

The M88 series feature 12" potting fans with filter inside the power module
compartment. The potting fans are designed long service life that provides high
reliability. They feature detection of "FAN-FAIL" alarm as well as power de-rating
behavior for safety operation. The Cooling Fan kit is easy to be removed and
cleaned. As a result, the replacement of fans is also smart.

Waterproof connectors

Hand Grip
12” Potting Fan with filter

Figure 5-7 : 12" Potting fan kit

ATTENTION
- The smart fans and filter cleaning depends on the quality of the environment.
- The smart fans and filter need to be cleaned every 6 months for their normal
use, however,
- The smart fans and filter cleaning is required every 1 month or every quarter
of the year, if necessary.

50
 Maintenance

1.Wiring Box compartment (WB): User should disassemble the top 2 pcs
screws (2 Black ones as shown in Figure 5-8) outside the fan cabinet and
disconnect the connector (white one as shown in Figure 5-8) right in front of
the fan cover. Then replace new fan and reassemble the 2 pcs screws and plug
in the connector.

Figure 5-8 : Disassembling fan inside the wiring box compartment (M88H_122 only)

2. Power Module compartment (PM):

Figure 5-9 shows one side (the right-hand side) of the PM compartment only
due to the symmetry of the air oulets. Therefore, the following Figure 5-9
shows one side only.

(1) User should disassemble the 4 pcs screws on the air oulet filter panel.
(2) Disconnect the connector (white as shown at the top left corner of second
sub-picture) and unscrew the 4 pcs on this side and 4 pcs on the other side
(total 8 screws) at the same time.
(3) Make sure both the left 2 and right 2 screws are removed.
(4) Pull out the drawer of the fans.
(5) This sub-picture shows the overview of the smart fans.

51
Maintenance

① ②
③ ④

Figure 5-9 : Disassembling fans inside the power module compartment (showing one side only)

52
 Maintenance

Figure 5-10 illustrates filters location of M88 series models.

Figure 5-10 : Removal of filters

53
Maintenance

5.3 De-Commissioning
If it is necessary to put the device out of operation for maintenance and / or
storage, please follow the instructions below.

DANGER : ELECTRICAL HARZARD!!

To avoid any serious injuries, please follow the procedures:

- Switch off Manual Switch to shut down the inverter.
- Switch off AC circuit breaker to disconnect with electricity grid.
- Switch off the PV array switch to disconnect from the PV array.
- Use proper voltmeter to confirm that the AC and DC power are disconnected
from the unit.
- Remove the AC terminal immediately to completely disconnect from electricity grid.
- Remove the DC terminals to disconnect from PV Array.
- Remove the communication module RS-485 connection from the computer.

CAUTION : HOT SURFACES, DO NOT TOUCH !

- Please be careful of hot surfaces if the inverter is just shutting down.

- Do not perform any task until the product cool down sufficiently.

CAUTION : POSSIBILE INJURY !

- The inverter weighs more than 80 kg (177 lb). The risk of injury may happen
when the inverter is carried incorrectly or dropped during transported or when
attaching or removing it from the wall mounting bracket.

ATTENTION

- Please be careful of the screws and nuts after removing them. Do not leave
them at any corner inside the wiring box compartment.

54
 Maintenance

5.3.1 Disassemble the Wiring box compartment

In order to decommission the inverter of its service life, please
follow the following instructions.

In order to disassemble the wiring box compartment (WB) if neccessary, please

follow the following instructions.
1. Please make sure turning off the external AC breaker and DC switches
2. Double-check the inverter is shutted down and there is no electrical hazard.
3. Figure 5-11 shows the correct way to turn off the DC swiches.

ON

I : Switch is ON
O : Switch is OFF

Figure 5-11 : The ON/OFF positions of DC Switches (M88H_122 only)

55
Maintenance

Please confirm both the AC and DC power is turned off.

4. Open the wiring box compartment lid.
5. Then remove AC, DC, communication cables.
6. Unscrew those screws shown in Figure 5-12.

AC cables DC cables

Communication
cables

Figure 5-12 : Remove AC, DC, and communication cables and then unscrew 6 screws

56
 Maintenance

7. Unscrew 8 screws and use hands to grip tightly to separate the wiring box
compartment from the power module compartment as shown in Figure 5-13.
8. Make sure the packing has been installed.

Figure 5-13 : Remove 8 screws and then separate WB from PM

57
Error message and Trouble Shooting

6 Error message and Trouble Shooting

ERROR

Message Possible cause Action

1. Actual utility frequency is over 1. Check the utility frequency

AC Freq
the OFR setting 2. Check country setting
High
2. Incorrect country setting 3. Contact our customer service for
(E01)
3. Detection circuit malfunction technical support

1. Actual utility frequency is under 1. Check the utility frequency

AC Freq
the UFR setting 2. Check country & Grid setting
Low
2. Incorrect country or Grid setting 3. Contact our customer service for
(E02)
3. Detection circuit malfunction technical support

Grid Quality Non-linear load in Grid and near Grid connection of inverter need to be
(E07) to inverter far away from non-linear load if necessary

1. Check the AC connection in accordance

HW Con.
1. Wrong connection in AC terminal with the user manual
Fail
2. Detection circuit malfunction 2. Contact our customer service for
(E08)
technical support

1. Switch on AC breaker
No Grid 1. AC breaker is OFF
2. Check the connection in AC terminal and
(E09) 2. Disconnect in AC terminal
make sure it connects to inverter

1. Actual utility voltage is under

AC Volt 1. Check the utility voltage within the suitable
the UVR setting
Low range
2. Incorrect country or Grid setting
(E10, E15, 2. Check country & Grid setting
3. Wrong connections in AC terminal
E20) 3. Check the connection in AC terminal
4. Detection circuit malfunction

1. Actual utility voltage is over the

AC Volt 1. Check the utility voltage within the suitable
OVR setting
High range
2. Utility voltage is over the Slow
(E11, E13, 2. Check country & Grid setting
OVR setting during operation
E16, E18, 3. Contact our customer service for
3. Incorrect country or Grid setting
E21, E23) technical support
4. Detection circuit malfunction

1. Modify the solar array setting, and

Solar1 1. Actual Solar1 voltage is over
make the Voc less than 1000Vdc
High 1000Vdc
2. Contact our customer service for
(E30) 2. Detection circuit malfunction
technical support

58
 Error message and Trouble Shooting

ERROR

Message Possible cause Action

1. Modify the solar array setting, and

Solar2 1. Actual Solar2 voltage is over
make the Voc less than 1000Vdc
High 1000Vdc
2. Contact our customer service for
(E31) 2. Detection circuit malfunction
technical support

1. PV array insulation fault 1. Check the insulation of Solar inputs

2. Large PV array capacitance 2. Check the capacitance, dry PV panel
Insulation
between Plus to Ground or if necessary
(E34)
Minus to Ground or both. 3. Contact our customer service for
3. Detection circuit malfunction technical support

Table 6-1 : Error Message

Warning

Message Possible cause Action

1. Actual Solar1 voltage is under

1. Check the Solar1 voltage connection
the limit
Solar1 to the inverter terminal
2. Some devices were damaged
Low 2. Check all switching devices in boost1
inside the inverter if the actual
(W01) 3. Contact our customer service for
Solar1 voltage is close to "0"
technical support
3. Detection circuit malfunction

1. Actual Solar2 voltage is under

1. Check the Solar2 voltage connection
the limit
Solar2 to the inverter terminal
2. Some devices were damaged
Low 2. Check all switching devices in boost2
inside the inverter if the actual
(W02) 3. Contact our customer service for
Solar2 voltage is close to "0"
technical support
3. Detection circuit malfunction

1. Remove the object that stuck in the

1. One or more fans are locked
fan(s)
2. One or more fans are defective
HW FAN 2. Replace the defective fan(s)
3. One ore more fans are
(W11) 3. Check the connections of all fans
disconnected
4. Contact our customer service for
4. Detection circuit malfunction
technical support

1. Inverter was struck by lighting. 1. Check inverter’s status

2. One or more SPD are defective 2. Replace the defective SPD
AC Surge 3. One or more SPD are 3. Check the connections of SPDs
DC Surge
disconnected 4. Contact our customer service for
4. Detection circuit malfunction technical support

Table 6-2 : Warning Message

59
Error message and Trouble Shooting

FAULT

Message Possible cause Action

1. Check the utility waveform.

DC
Grid connection of inverter need to be
Injection 1. Utility waveform is abnormal
far away from non-linear load if necessary
(F01, F02, 2. Detection circuit malfunction
2. Contact our customer service for
F03)
technical support

1. Check the installation ambient and

1. The ambient is over 60℃
Temperature environment
(The installation is abnormal)
(F05) 2. Contact our customer service for
2. Detection circuit malfunction
technical support

1. Check the installation ambient and

1. Ambient temperature is
Temperature environment
<-30 ℃
(F07) 2. Contact our customer service for
2. Detection circuit malfunction
technical support

1. Check the installation ambient and

HW NTC1 1. Ambient temperature
environment
Fail >90 ℃ or <-30 ℃
2. Contact our customer service for
(F06) 2. Detection circuit malfunction
technical support

HW NTC2 1. Ambient temperature 1. Check the installation ambient and

Fail >90 ℃ or <-30 ℃ environment
(F08) 2. Detection circuit malfunction 2. Please contact our customer service

1. Check the installation ambient and

HW NTC3 1. Ambient temperature
environment
Fail >90 ℃ or <-30 ℃
2. Contact our customer service for
(F09) 2. Detection circuit malfunction
technical support

1. Check the installation ambient and

HW NTC4 1. Ambient temperature
environment
Fail >90 ℃ or <-30 ℃
2. Contact our customer service for
(F10) 2. Detection circuit malfunction
technical support

1. Driver circuit for relay is

1. Check the input voltage, must >150Vdc
Relay Test defective
2. Replace the defective relay
Open 2. Relay(s) is defective
3. Contact our customer service for
(F13) 3. Detection circuit malfunction
technical support
(Inverter voltage)

1. Check the input voltage, must >150Vdc

1. Insufficient input power
HW DSP 2. Check the auxiliary circuitry inside the
2. Auxiliary power circuitry
ADC1 inverter
malfunction
(F15) 3. Contact our customer service for
3. Detection circuit malfunction
technical support

60
 Error message and Trouble Shooting

FAULT

Message Possible cause Action

1. Check the input voltage, must >150Vdc

1. Insufficient input power
HW DSP 2. Check the auxiliary circuitry inside the
2. Auxiliary power circuitry
ADC2 inverter
(F16) malfunction
3. Contact our customer service for
3. Detection circuit malfunction
technical support

1. Check the input voltage, must >150Vdc

1. Insufficient input power
HW DSP 2. Check the auxiliary circuitry inside the
2. Auxiliary power circuitry
ADC3 inverter
malfunction
(F17) 3. Contact our customer service for
3. Detection circuit malfunction
technical support

1. Check the input voltage, must >150Vdc

1. Insufficient input power
HW Red 2. Check the auxiliary circuitry inside the
2. Auxiliary power circuitry
ADC1 inverter
malfunction
(F18) 3. Contact our customer service for
3. Detection circuit malfunction
technical support

1. Check the input voltage, must >150Vdc

1. Insufficient input power
HW Red 2. Check the auxiliary circuitry inside the
2. Auxiliary power circuitry
ADC2 inverter
malfunction
(F19) 3. Contact our customer service for
3. Detection circuit malfunction
technical support

1. The calibration is incorrect 1. Check the accuracy of current and power

HW Eff.
2. Current feedback circuit is 2. Check the current feedback circuit
(F20)
defective inside the inverter

1. DSP is idling
1. Contact our customer service for
HW 2. The communication
technical support
COMM1 connection is disconnected
2. Check the connection interface RS-485
(F23) 3. The communication circuit
3. Check the communication card
is malfunction

HW 1. Red. CPU is idling

Contact our customer service for
COMM2 2. The internal communication
technical support
(F22) connection is disconnected

1. PV array insulation fault

1. Check the insulation of Solar inputs
2. Large PV array capacitance
2. Check the capacitance (+ <-> GND &
between Plus to Ground or
Ground Cur. - <-> GND), must < 2.5uF. Install a
Minus to Ground
(F24) external transformer if necessary
3. Either side of boost driver
3. Contact our customer service for
or boost choke malfunction
technical support
4. Detection circuit malfunction

61
Error message and Trouble Shooting

FAULT

Message Possible cause Action

1. Power line is disconnected

1. Check the power lines inside the inverter
HW Con. Fail inside the inverter
2. Contact our customer service for
(F26) 2. Current feedback circuit is
technical support
defective

1. Check the RCMU connection inside the

RCMU Fail 1. RCMU is disconnected inverter
(F27) 2. Detection circuit malfunction 2. Contact our customer service for
technical support

1. One or more relays are

RLY Short sticking Contact our customer service for
(F28) 2. The driver circuit for the technical support
relay malfunction

1. One or more relays are

abnormal
RLY Open 2. The driver circuit for the Contact our customer service for
(F13, F29) relay malfunction technical support
3. The detection accuracy is
not correct for Vgrid and Vout

1. Not totally independent or

parallel between inputs 1. Check the inputs connections
Bus Unbal. 2. PV Array short to Ground 2. Check the PV Array insulation
(F30) 3. Driver for boost is defective 3. Contact our customer service for
or disconnected technical support
4. Detection circuit malfunction

1. Driver for boost is defective

2. Voc of PV array is over
HW Bus OVR 1000Vdc Contact our customer service for
(F31, F33, F35) 3. Surge occurs during technical support
operation
4. Detection circuit malfunction

1. Surge occurs during

operation
AC Cur. High
2. Driver for inverter stage is Contact our customer service for
(F36, F37, F38,
defective technical support
F39, F40, F41)
3. Switching device is defective
4. Detection circuit malfunction

1. Test current loop is broken

HW CT A Fail Contact our customer service for
2. CTP3 is defective
(F42) technical support
3. Detection circuit malfunction

62
 Error message and Trouble Shooting

FAULT

Message Possible cause Action

1. Test current loop is broken

HW CT B Fail Contact our customer service for
2. CTP4 is defective
(F43) technical support
3. Detection circuit malfunction

1. Test current loop is broken

HW CT C Fail Contact our customer service for
2. CTP5 is defective
(F44) technical support
3. Detection circuit malfunction

1. Check the utility waveform. Grid connection

of inverter need to be far away from
1. Large Grid harmonics non-linear load if necessary
HW AC OCR
2. Switching device is defective 2. Check all switching devices in inverter
(F45)
3. Detection circuit malfunction stage
3. Contact our customer service for
technical support

1. Switching device in boost

1. Check all switching device in boost
DC Cur. High is defective
2. Check the driver circuit for boost inside
(F60, F61, 2. Driver for boost is defective
the inverter
F70, F71) 3. Input current detection
3. Check input current detection circuit
circuit malfunction

HW DC RLY One or more DC relays are Please contact our customer service for
(F76) abnormal technical support

Table 6-3 : Fault Message

63
Technical Data

7 Technical Data
Model M88H_121 M88H_122
DC Input
Max. input power Vac400: 76kW / Vac480: 91kW
Recommended PV power Vac400V : 90kW / Vac480V : 110kW
Occasionally maximum voltage 1100 V *
Operating voltage range 200 - 1000 V
Start voltage > 250 V
MPP voltage, rated power Vac400V : 500 - 800V / Vac480V : 600 - 800V
Rated voltage Vac400V : 595V / Vac480V : 710V
MPP tracker 2
Max. input current / Each MPPT 140 / 70A
Max. Isc / Each MPPT 180 / 90A
2-250kcmil terminal 18 pairs of
Connection type
block for 2 MPPTs MC4 connector
Type II SPD
15A string fuses
DC switch
AC Output
Max. output power Vac400: 73kW / Vac480: 88kW

Max. output current 106A

Inrush current 40A / 100μs
Maximum output fault current (rms) 115.4A (rms)
Maximum output over
current protection 125A

Rated voltage 3 Ph 400V & 480V Δ / Y

Operating voltage range Vac400V : ±30% / Vac480V : ±10%
Operating frequency range 50/60Hz ± 5Hz
Power factor 1 at rated power, 0.8 ind ~ 0.8 cap adjustable
Protection Type II SPD
THD < 3%
Connection type 50 ~120 mm2 35 ~95 mm2

Night time consumption <3W

* The max withstand voltage is 1100Vdc. (the inverter stops to operate when the PV voltage is over 1000Vdc) : Available
About 1000Vdc above application, please refer to appendix. : Not Available

64
 Technical Data

Model M88H_121 M88H_122

Efficiency

Peak Effieiency 98.8 %

Euro Effieiency 98.5 %

Information

Communication port RS-485

Display 20 x 4 LCD

Regulation

IEC 62109-1/-2
VDE-AR-N 4105
EN 61000-6-1
EN 61000-6-2
EN 61000-6-3
EN 61000-6-4
CE compliance

General Data

Operating temp. range -25~60℃ (Max power: -25~35℃)

Protection Level IP65

Operating elevation < 3000 m

Cooling Forced air cooling plus Smart Fans control

Dimension (W x H x D) (mm) 615 x 962 x 275

Weight (kg) 84

Noise (1m) 75.8 dB

Overvoltage category AC output :III, DC Input :II

Maximum backfeed
0
current to the array

Protective Class I

Pollution Degree 3

Humidity range 4-100%

Table 7-1 : Specifications for M88H

65
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Version 1.02 | 2016 | Oct.