TYPE TNS-2 OCR CHECKER

FOR
ELECTRONIC MCCBs

INSTRUCTION MANUAL

Applicable breaker types: TemBreak

TemBreak2

Notice
Please retain this manual for future reference.

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 Table of Contents
Page
1. SAFETY NOTICES.......................................................................................................... 3

2. Ratings and Specifications .............................................................................................. 4

3. Parts Names and Functions ............................................................................................ 5

4. Preparation Before the Test............................................................................................. 7

4-1. Preparation Before the Test (1) ................................................................................. 7

4-2. Preparation Before the Test (2) ................................................................................. 8

4-2-1. For TemBreak......................................................................................................... 8

4-2-2. For TemBreak2....................................................................................................... 10

5. TESTING PROCEDURES............................................................................................. 13

5-1. Testing Procedure for Pickup Current Value for Long Time Delay Trip Function. 13

5-2. Testing Procedure for Trip Time Setting Value for Long Time Delay Trip Function
............................................................................................................................. 14

5-3. Testing Procedure for Trip Current Setting Value for Short Time Delay Trip
Function (definite time characteristic) .................................................................. 15

5-4. Testing Procedure for Trip Time Setting Value for Short Time Delay Trip Function
(definite time characteristic) ................................................................................. 20

5-5. Testing Procedure for Trip Time Setting Value for Short Time Delay Trip Function (I2t
characteristic) ...................................................................................................... 21

5-6. Testing Procedure for Trip Current Setting Value for Instantaneous Trip Function
............................................................................................................................. 21

5-7. Testing Procedure for Trip Current Setting Value for Ground Fault Trip Function
............................................................................................................................. 24

5-8. Testing Procedure for Trip Time Setting Value for Ground Fault Trip Function ... 25

5-9. Adjustment........................................................................................................... 25

The type TNS-2 OCR checker facilitates on-site testing of the OCR (overcurrrent release) installed on electronic
MCCBs, TemBreak and TemBreak2. Carefully read this manual to ensure proper use of the OCR checker.

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1. SAFETY NOTICES
Thank you for purchasing the type TNS-2 OCR checker.
This chapter gives you the important information on safety. Prior to the use of the Type TNS-2 OCR Checker, be sure to
thoroughly read this and subsequent chapters of this instruction manual and all the other documents that come with this product.
To ensure the proper use, gain the full knowledge of the OCR checker and familiarize yourself with all the safety information and
precautions. This chapter classifies the following safety precautions as “ CAUTION”, which indicates a potentially hazardous
situation that, if not avoided, may result in minor or moderate injury, or otherwise may result in physical property damage only.
A failure in observing any instruction given under “ CAUTION” might lead to a more serious result depending on the situation.
Be sure to observe these instructions, all of which include very important information.

CAUTION
„ Common to transportation, operations, and storage
• Do not store the OCR checker in an abnormal environment where it is exposed to high temperature, high humidity,
excessive dust, corrosive gas, vibrations, shocks, or any other similar condition. Avoid direct sunlight and maintain the
ambient temperature in a range between –20°C and 55°C and relative humidity in a range between 45% and 85% (without
condensation). Otherwise, a failure may result.
„ Transportation
• Do not drop the OCR checker, nor give a shock to it. The OCR checker is an electronic product requiring careful handling.
Improper handling will result in a failure.
„ Operations
• The test using the OCR checker shall be performed by a qualified operator who has the necessary expertise. The operator
shall be familiar with the knowledge, safety information, and precautions on moulded case circuit breakers, OCRs, and
OCR checkers. Improper handling may lead to an unexpected accident.
• Before testing an OCR, be sure to make preparations for the test in accordance with Chapter 4. Preparation Before the Test.
Otherwise, undesired tripping or a failure may result.
• To insert the power plug into or remove it from the OCR checker, or to insert the signal plug into or remove it from the
OCR, be sure to check in advance that the OCR checker is OFF. Otherwise, a failure may result.
• To use each switch located on the OCR checker, press it with your finger at a force of 2~4 N. Using excessive force or a
sharp-tipped hard tool can cause a failure.
• Be sure to determine the current flowing through the OCR before using the OCR checker to test the OCR. An excessive
current may result in damage to the OCR.
• After the test, be sure to put the set values on the OCR back to the previous ones. Otherwise, fire or undesired tripping may
occur.

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2. Ratings and Specifications
Tables 1 and 2 show the ratings and specification of the OCR checker.
Table 1 Rating and specification 1 of the type TNS-2 OCR checker
Item Description
Applicable breakers Electronic breakers TemBreak and TemBreak2
Specify either 100 – 120 VAC or 200 – 240 VAC (both 50/60 Hz) when
Rated voltage
placing an order.
Power consumption 7 VA
External dimensions of main unit W250 mm × H85 mm × D160 mm
Weight of main unit 400 kg
Force for pressing a switch 2–4N
Allowable ambient temperature –5 to 40°C during use, –20 to 55°C during storage
Allowable humidity During use and storage: RH 45% – 85%
Power cord with AC adaptor (approx. 2 m)
• With 2P-to-3P conversion plug (for 100 – 110 VAC)
• SE type (for 200 – 240 VAC)
Accessories Signal cable (approx. 2 m)
• For TemBreak (approx. 2 m)
For TemBreak2: 250AF (approx. 2 m)
400AF (approx. 2 m)

Table 2 Rating and specification 2 of the type TNS-2 OCR checker

Item Description
Measurable OCR functions
* For ◯1 through ◯11 , see the following “Output for signals” rows.

TemBreak TemBreak2
z Pickup current value for long time delay trip z Pickup current value for long time delay trip
function◯ 1 function◯ 1 ◯9

z Trip time setting value for long time delay trip z Trip time setting value for long time delay
function◯ 2 ◯8 trip function ◯ 2 ◯ 8 ◯10

z Trip current setting value for short time delay z Trip current setting value for short time
trip function◯ 3 delay trip function ◯ 3 ◯
8

z Trip time setting value for short time delay z Trip time setting value for short time delay
trip function ◯ 4 ◯
9 trip function ◯ 4 ◯ 8 ◯10

z Trip current setting value for instantaneous z Trip current setting value for instantaneous
trip function ◯ 5 trip function ◯ 5 ◯ 8

z Trip current setting value for ground fault trip z Trip current setting value for ground fault
function ◯ 6 trip function ◯ 6 ◯ 9

z Trip time setting value for ground fault trip z Trip time setting value for ground fault trip
function ◯ 7 ◯9 function ◯ 7 ◯9 ◯11

◯1 0-140mA ◯1 0-200mA

◯2 0-750mA ◯2 0-750mA

◯3 0-750mA ◯3 0-1450mA
Output signal value 4 0-800mA 4 0-1450mA
◯ ◯
setting range
◯5 0-800mA ◯5 0-1450mA

◯6 0-140mA ◯6 0-140mA

0-140mA 7 0-140mA
Output for signals

◯7 ◯
Accuracy of output
±1% (at 100 mA) ±1% (at 100 mA)
signal value
◯8 Half-wave rectification
Output method Full-wave rectification
◯9 Full-wave rectification

Output time
0.00–999 sec 0.00–999 sec
measurement range
◯8 0.00 – 99.9 sec: 0.1 sec or ±1%, whichever is ◯ 10 0.00 – 99.9 sec: 0.1 sec or ±1%, whichever

Output time greater is greater

measurement 100 – 999 sec: 1 sec or ±1%, whichever is 100 – 999 sec: 1 sec or ±1%, whichever is
accuracy greater greater
◯9 0.1 sec or ±1%, whichever is greater 11 0.1 sec or ±1%, whichever is greater
◯

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3. Parts Names and Functions
Parts names and functions of the OCR checker are given below. Figs. 1 and 2 show the appearance of the OCR checker.
◯
20

◯
2

◯
16
◯
1
◯
3
◯
13
◯
4
◯
7
◯
14

◯
6

◯
5

◯
15
◯
12
◯
11
◯
8 ◯
9 ◯
10

Fig. 1 Appearance of the type TNS-1 OCR checker (1)

◯
17

◯
18

◯
19

Fig. 2 Appearance of the type TNS-1 OCR checker (2)

◯
1 Signal connector (round type): A signal cable connector for the OCR checker
◯
2 Power connector (square type): A power cable connector for the OCR checker
◯
3 Signal cable (approx. 2 m): A cable connecting between the OCR and the OCR checker. The OCR checker gives
the output for power and signals to the OCR and receives the trip signal and pretrip alarm signal from the OCR via
this cable.
◯
4 Power cord (approx. 2 m): A cord used to supply power to the OCR checker.

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 5 Signal connector (square type): A signal cable connector for the OCR. Available in three types:
◯

For TemBreak For TemBreak2 (250AF) For TemBreak2 (400AF)

Fig. 3 Available signal connector types

6 Power plug: A power cord plug for the power outlet. Available in two types:
◯

100 – 110 VAC plug 200 – 240 VAC plug

(With 2P-to-3P conversion plug) (SE type)

Fig. 4 Available power plug types

100 – 110 VAC plug: For use in Japan only

200 – 240 VAC plug: For use in Europe (Austria, Netherlands, Germany, Sweden, Denmark, Norway, Finland and Belgium)

◯7 POWER switch: A switch used to turn ON/OFF the OCR checker.

◯8 Breaker selector switch: Use to select a breaker type, TemBreak or TemBreaker2.
◯9 Element selector switch: Use to select an item for which the OCR is checked.
◯
10 Current adjusting knob: Use to increase or decrease the signal output level.
◯
11 Reset switch: Use to clear indications after completion of a test or to cancel a test.
◯
12 Start switch: Use to start a test. When this pushbutton switch is pressed, a test current is applied to the OCR.
◯
13 NORMAL lamp (green LED): Illuminates when the OCR has passed a test.
◯
14 ABNORMAL lamp (red LED): Illuminates when an abnormality was found in the OCR during a test.
◯
15 WAIT lamp (red LED): Illuminates when the OCR checker cannot continue testing because of an overheat in the
checker. Wait until the lamp goes off before restarting the test.
◯
16 Display: Provides indication of current or time measurement depending on the element selector switch position.
◯
17 Power connector socket: A socket for the power connector (square type).
◯
18 Signal connector socket: A socket for the signal connector (round type).
◯
19 Fuse (2A): For power supply of the OCR checker.
◯
20 Protection characteristic curve: Shows the numbers of test items that correspond to those of element switch positions.

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4. Preparation Before the Test
CAUTION
• Before testing an OCR, be sure to make preparations for the test in accordance with Chapter 4 Preparation Before the
test. Otherwise, undesired tripping or a failure may result.
• To insert the power plug into or remove it from the OCR checker, or to insert the signal plug into or remove it from the
OCR, be sure to check in advance that the OCR checker is OFF. Otherwise, a failure may result.

This chapter describes the preparations for the test. Make the preparations in accordance with the following steps.

4-1. Preparation Before the Test (1)

1) Make sure that the display of the OCR checker provides no indications and all lamps are off.
2) Plug the round signal connector at one end of the signal cable into the signal terminal port in the side of the OCR checker.
See Fig. 5

Round signal connector

Fig. 5 Connection of the round signal connector

Make sure that the square signal connector at the other end of the signal cable is matched to the breaker subject to testing.
See Fig. 3.

3) Check the rated supply voltage indicated beside the power terminal port in the side of the OCR checker and plug the square
power connector into the power terminal port. See Fig. 6

Square power
connector

Fig. 6 Connection of the power terminal

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4-2. Preparation Before the Test (2)

4-2-1. For TemBreak

If the breaker subject to testing is located in a system, open the breaker and turn off an upstream breaker or the like to isolate the
breaker main and control circuits from any power.
1) Peel off the sealing sticker on the OCR cover, loosen the OCR cover mounting screw under the sticker and remove the
OCR cover from the breaker. See Fig. 7.

OCR cover mounting screw

OCR cover Sealing sticker Panhead screw M3×6

Fig. 7 Removing the OCR cover

After completion of a test, be sure to reinstall the OCR cover with the mounting screw and seal the screw with a spare
sealing sticker.
Spare sealing stickers are in the rear pocket of the OCR cover.

2) Make sure that the power switch of the OCR checker is in the OFF position and the current adjusting knob is turned full
counterclockwise. See Fig. 8.

Power
Current adjusting knob
switch

Fig. 8 Power switch and current adjusting knob

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3) Set the breaker selector switch to the TemBreak position. See Fig. 9.

Breaker selector switch

Fig. 9 Breaker selector switch

4) Make sure that the display of the OCR checker provides no indications and all lamps are off. Plug the square signal
connector of the signal cable into the TEST IN port of the breaker. See Fig. 10.

Square signal connector

Fig. 10 Connection of the square signal terminal

5) Plug the power cable into an outlet.

6) It is recommended that OCR settings be noted before testing so that the settings can be returned to the original values after
testing.

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4-2-2. For TemBreak2
1) If the breaker subject to testing is located in a system, open the breaker and turn off an upstream breaker or the like to
isolate the breaker main and control circuits from any power.
2) For a 250AF breaker, use a flatblade screwdriver to pry off the test terminal cap. See Fig. 11.

Test terminal cap

Fig. 11 Prying off the test terminal cap

3) For a 400AF breaker, peel off the sealing sticker on the OCR cover, pry the OCR cover with a flatblade screwdriver and
slide it to remove. See Figs. 12 and 13.

Sealing sticker

Fig. 12 Sealing sticker

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 OCR cover
Fig. 13 Removing the OCR cover

After completion of a test, be sure to reinstall the OCR cover and seal it with a spare sealing sticker.
Spare sealing stickers are in the rear pocket of the OCR cover.

4) Make sure that the power switch of the OCR checker is in the OFF position and the current adjusting knob is turned full
counterclockwise. See Fig. 8.

5) Set the breaker selector switch to the TemBreak2 position. See Fig. 14.

Breaker selector switch

Fig. 14 Breaker selector switch

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 6) Make sure that the display of the OCR checker provides no indications and all lamps are off. Plug the square signal
terminal of the signal cable into the TEST IN port of the breaker. See Fig. 15.

Square signal connector

Square signal connector
(250AF breaker) (400AF breaker)

Fig. 15 Connection of the square signal connector

7) Plug the power cable into an outlet.

8) The test involves changes in OCR settings. It is recommended that OCR settings be noted before testing so that the settings
can be returned to the original values after testing.

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5. TESTING PROCEDURES
This chapter describes the procedures for testing the OCR checker.

CAUTION
z To use each switch located on the OCR checker, press it with your finger at a force of 2~4 N. Using excessive force or a
sharp-tipped hard tool can cause a failure.
z Be sure to determine the current flowing through the OCR before using the OCR checker to test the OCR. An excessive
current may result in damage to the OCR.
z After the test, be sure to put the set values on the OCR back to the previous ones. Otherwise, fire or undesired tripping may
occur.

1) Press the power switch of the OCR checker to turn on the power. See Fig. 1.
2) Press the reset switch. "O" will be indicated on the display. See Fig. 1.

Follow the procedures shown below for testing the OCR.

5-1. Testing Procedure for Pickup Current Value for Long Time Delay Trip
Function
The OCR should have been so adjusted as to trip open the breaker when the current flowing through the breaker reaches a
setpoint that is between 105% and 125% of the rated current. When the current flowing through the breaker reaches the setpoint,
a red LED for the breaker OCR turns on. See Fig. 16.

Indicator Indicator Indicator

For TemBreak For TemBreak2 (250AF) For TemBreak2 (400AF)

Fig. 16 Indicator LED for the breaker OCR

1) Calculate the criterion value of the current flowing through the breaker as follows:
(For TemBreak)
[ I1 / ICT × 50 × 1.05 ] < IT ≤ [ I1 / ICT × 50 ×1.25 ] (mA)
(For TemBreak2)
[ I1 / ICT × 100 × 1.05 ] < IT ≤ [ IR / ICT × 100 ×1.25 ] (mA)

I1, IR: Trip pickup current setting (A)

IT: Current flowing through the OCR (mA)
ICT, ICT: CT rated primary current (A) *1
*1: The value of ICT is indicated on the OCR.
The CT rated secondary current is 50 mA for TemBreak and 100 mA for TemBreak2.
2) Set the element selector switch to the LONG TIME-P.U. ◯
1 position. See Fig. 1.

3) Press the start switch to start energization. See Fig. 1.

4) Turn the current adjusting knob clockwise to increase the current until the indicator LED for the breaker OCR turns on.
See Fig. 1.

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 5) Turn the current adjusting knob counterclockwise to decrease the current until the LED turns off. See Fig. 1.
6) Repeat steps 4 and 5 a few times and note the value at which the LED turns on. *2
*2: If the breaker has the pretrip alarm (PTA) function, the LED for the breaker OCR starts blinking
when the current flowing through the breaker reaches the PTA pickup current setting (IP).
The LTD trip pickup function will be activated if the current continues exceeding the trip pickup
current setting.

7) Compare the LTD trip pickup current indicated on the display of the OCR checker with the criterion value calculated in
step 1) above. The OCR has passed the test if the indicated value falls within the range of criterion values.
8) After completion of the test, turn the current adjusting knob to the MIN position without delay. See Fig. 1.
9) Press the reset switch. See Fig. 1. "0" will be indicated on the display of the OCR checker.

5-2. Testing Procedure for Trip Time Setting Value for Long Time Delay
Trip Function
1) Consult the table below to change the OCR setting as appropriate.
After completion of the test, be sure to return the setting to the original value.
Breaker OCR setting to be changed
TemBreak If I2 is set to 6 or less, change it to 10.
TemBreak2 If "Characteristics" is set to 3 or less, change it to 4 or more.

2) Calculate the current flowing through the OCR as follows:

(For TemBreak)
IT = I1 / ICT × 50 × 6 (mA)
(For TemBreak2)
IT = IR / ICT × 100 × 6 (mA)

I1, IR: Trip pickup current setting (A)

IT: Current flowing through the OCR (mA)
ICT, ICT: CT rated primary current (A) *3
*3: The CT rated secondary current is 50 mA for TemBreak and 100 mA for TemBreak2.

3) 2 position. See Fig. 1.

Set the element selector switch to the LONG TIME-I ◯
4) Press the start switch to start energization. See Fig. 1.
5) Turn the current adjusting knob clockwise to increase IT until it reaches the value calculated in step 1) above. See Fig. 1.
6) Press the reset switch. See Fig. 1. "0" will be indicated on the display of the OCR checker.
7) Set the element selector switch to the LONG TIME-T ◯ 2 position. See Fig. 1.

8) Press the start switch to start energization. See Fig. 1.

9) The breaker will trip open when the trip pickup time setting has elapsed. The NORMAL lamp will turn on and the display
provide indication of the LTD trip pickup time setting. *4
*4: When the OCR is activated, the current consequently turns off.
10) Compare the LTD trip pickup time indicated on the display of the OCR checker with the setting (T1 for TemBreak or tR
for TemBreak2). The OCR has passed the test if the indicated value falls within the range of criterion value ±20%.
11) Return the current adjusting knob to the MIN position without delay. See Fig. 1.
12) Press the reset switch. See Fig. 1. "0" will be indicated on the display of the OCR checker.

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5-3. Testing Procedure for Trip Current Setting Value for Short Time Delay
Trip Function (definite time characteristic)
Before testing a TemBreak, make sure that the SHORT TIME I2t switch on the OCR is in the OFF position. If this switch is in
the ON position, turn it OFF. After completion of the test, return the switch position to ON.

1) Criterion value
(For TemBreak)
Calculate the criterion value as follows:

IT = I2 / ICT × 50 (mA)

I2: Short time delay trip pickup current setting (A)

IT: Current flowing through the OCR (mA)
ICT: CT rated primary current (A) *5
*5 The CT rated secondary current is 50 mA.

(For TemBreak2)
Select the criterion value from Table 3 of Page 16 to 19.

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 Table 3-1 Criterion value for Short Time Delay Trip Function (1)
Breaker Rated Current Setting value of rated current Setting value of characteristics Criterion value for Short
Types [A] adjustment dial for Breakers adjustment dial for Breakers Time Delay Trip function
[mA]
S250-NE 40 1,2 100
S250-GE 125 0.4 3 200
S250-PE 160 4,5 400
H250-NE 250 1,2 125
0.5 3 250
4,5 500
1,2 158
0.63 3 315
4,5 630
1,2 200
0.8 3 400
4,5 800
1,2 225
0.9 3 450
4,5 900
1,2 238
0.95 3 475
4,5 950
1,2 250
1 3 500
4,5 1000
S400-NE 400 1,2 100
S400-GE 0.4 3 200
H400-NE 4,5,6,7 400
L400-NE 1,2 125
0.5 3 250
4,5,6,7 500
1,2 158
0.63 3 315
4,5,6,7 630
1,2 200
0.8 3 400
4,5,6,7 800
1,2 225
0.9 3 450
4,5,6,7 900
1,2 238
0.95 3 475
4,5,6,7 950
1,2 250
1 3 500
4,5,6,7 1000

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Table 3-2 Criterion value for Short Time Delay Trip Function (2)
Breaker Rated Current Setting value of rated current Setting value of characteristics Criterion value for Short
Types [A] adjustment dial for Breakers adjustment dial for Breakers Time Delay Trip function
[mA]
S630-CE 630 1,2 100
S630-GE 0.4 3 200
4,5,6,7 320
1,2 125
0.5 3 250
4,5,6,7 400
1,2 158
0.63 3 315
4,5,6,7 504
1,2 200
0.8 3 400
4,5,6,7 640
1,2 213
0.85 3 425
4,5,6,7 680
1,2 225
0.9 3 450
4,5,6,7 720
1,2 238
0.95 3 475
4,5,6,7 760
1,2 250
1 3 500
4,5,6,7 800
S800-NE 800 1,2 100
0.4 3 200
4,5,6,7 320
1,2 125
0.5 3 250
4,5,6,7 400
1,2 158
0.63 3 315
4,5,6,7 504
1,2 200
0.8 3 400
4,5,6,7 640
1,2 225
0.9 3 450
4,5,6,7 709
1,2 238
0.95 3 475
4,5,6,7 742
1,2 250
1 3 500
4,5,6,7 776

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 Table 3-3 Criterion value for Short Time Delay Trip Function (3)
Breaker Rated Current Setting value of rated current Setting value of characteristics Criterion value for Short
Types [A] adjustment dial for Breakers adjustment dial for Breakers Time Delay Trip function
[mA]
S1000-NE 1250 1,2 100
0.4 3 200
4,5,6,7 320
1,2 125
0.5 3 250
4,5,6,7 400
1,2 158
0.63 3 315
4,5,6,7 504
1,2 200
0.8 3 400
4,5,6,7 640
1,2 225
0.9 3 450
4,5,6,7 709
1,2 238
0.95 3 475
4,5,6,7 742
1,2 250
1 3 500
4,5,6,7 776
S1250-NE 1250 1,2 100
S1250-GE 0.4 3 200
4,5,6,7 400
1,2 125
0.5 3 250
4,5,6,7 500
1,2 158
0.63 3 315
4,5,6,7 630
1,2 200
0.8 3 400
4,5,6,7 800
1,2 225
0.9 3 450
4,5,6,7 900
1,2 238
0.95 3 475
4,5,6,7 939
1,2 250
1 3 500
4,5,6,7 977

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Table 3-4 Criterion value for Short Time Delay Trip Function (4)
Breaker Rated Current Setting value of rated current Setting value of characteristics Criterion value for Short
Types [A] adjustment dial for Breakers adjustment dial for Breakers Time Delay Trip function
[mA]
S1600-NE 1600 1,2 100
0.4 3 200
4,5,6,7 400
1,2 125
0.5 3 250
4,5,6,7 500
1,2 158
0.63 3 315
4,5,6,7 630
1,2 200
0.8 3 400
4,5,6,7 758
1,2 225
0.9 3 450
4,5,6,7 833
1,2 238
0.95 3 475
4,5,6,7 870
1,2 250
1 3 500
4,5,6,7 908

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 2) Set the element selector switch to the SHORT TIME-I ◯
3 position. See Fig. 1.

3) Turn the current adjusting knob a bit clockwise from the MIN position. See Fig. 1.
4) Press the start switch to start energization. See Fig. 1. *6
*6: ◯ 1 The duration of energization is as short as approx. 1500 ms. The current turns off
automatically after such a duration of time and the display of the OCR checker provides
indication of the value of current applied.
◯
2 Repeat the following steps to increase/decrease the current:
1) Press the reset switch.
2) Use the current adjusting knob to adjust the current. See Fig. 1.
3) Press the start switch. See Fig. 1.
4) Check the current flowing through the OCR
◯
3 Turning off the breaker will facilitate adjusting the current. If the breaker is on while the
current is adjusted, RESET and then ON operation will be required after the breaker trips
open.

5) The breaker will trip open when the current flowing thought the OCR exceeds the trip pickup current setting. The
NORMAL lamp will turn on and the display provide indication of the STD trip pickup current setting. See Fig. 1.
6) Compare the STD trip pickup current indicated on the display of the OCR checker with the criterion value calculated in
step 1) above. The OCR has passed the test if the indicated value falls within the range of criterion value ±15%.
7) Return the current adjusting knob to the MIN position. See Fig. 1. *7
*7: This step is not required if this test is followed by a test for STD trip pickup timing.

8) Press the reset switch. See Fig. 1. "0" will be indicated on the display of the OCR checker.

5-4. Testing Procedure for Trip Time Setting Value for Short Time Delay
Trip Function (definite time characteristic)
Before testing a TemBreak, make sure that the SHORT TIME I2t switch on the OCR is in the OFF position.
If the short time delay trip function is selected, the OCR operates at a definite time when the current flowing through the OCR
exceeds the trip pickup current setting.
During a test for short time delay trip timing, approx. 120% of the short time delay trip pickup current setting is applied to the
breaker.
1) Turn the current adjusting knob a bit more clockwise than for the test in section 5.3. See Fig. 1. *8
*8: When testing a TemBreak, make sure that the test current does not exceed the instantaneous trip
pickup current setting (I3). If the short time delay trip pickup current setting (I2) is too close to the
instantaneous trip pickup current setting (I3) to set the test current, however, maximize the
instantaneous trip pickup current setting for convenience of testing, and return it to the original
value after completion of the test.
2) Set the element selector switch to the SHORT TIME-T ◯ 4 position. See Fig. 1.

3) Press the start switch to start energization. See Fig. 1. *9

*9: The current turns off automatically approx. 1500 ms after the start of energization.

4) The breaker will trip open when the trip pickup time setting has elapsed. The NORMAL lamp will turn on and the display
provide indication of the STD trip pickup time setting. See Fig. 1.
5) Compare the STD trip pickup time indicated on the display of the OCR checker with the STD trip pickup time setting.
The OCR has passed the test if the indicated value falls within the range of setting ±20 ms.
6) Return the current adjusting knob to the MIN position. See Fig. 1.
7) Press the reset switch. See Fig. 1. "0" will be indicated on the display of the OCR checker.

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5-5. Testing Procedure for Trip Time Setting Value for Short Time Delay
Trip Function (I2t characteristic)
This section describes how to test the OCR when the SHORT TIME I2t switch on the OCR is in the ON position.

1) Calculation of the criterion value:

For the I2t characteristic, since the trip pickup timing is so adjusted that T2 is 0.1 to 0.3s when I2 = 10, 102 × T2 is assumed
to be constant. Consequently, the trip pickup time TX at I2 is given by

Tx = 102 × T2 / I22

If T2 = 0.2s, for example, the trip pickup time at I2 = 2 or I2 = 6 is as follows:

Tx1 = 102 × 0.2/22 = 5s
Tx2 = 102 × 0.2 / 62 ≈ 0.56s

Criterion values calculated as shown above are listed in the table 4.

Tables 4 Criterion values for short time delay trip time setting
Breaker I2 dial position
2 4 6 8 10
7.50 1.88 0.83 0.47 0.30
Short time delay trip
6.25 1.56 0.69 0.39 0.25
pickup time setting
5.00 1.25 0.56 0.31 0.20
3.75 0.94 0.42 0.23 0.15
T2(sec)
2.50 0.63 0.28 0.16 0.10

2) Adjust the test current so that the short time delay trip pickup current I2 is in a range of I1 × 6 to 8 according to steps 2 to 4
in section 5.3.
3) Set the element selector switch to the SHORT TIME-T ◯ 4 position. See Fig. 1.

4) Press the start switch to start energization. See Fig. 1.

5) Current I2 = I1 × 6 to 8 (A) will be applied to the breaker and the breaker trips open. The NORMAL lamp will turn on and
the display provide indication of the STD trip pickup time setting. See Fig. 1.
6) Compare the STD trip pickup time indicated on the display of the OCR checker with the STD trip pickup time setting.
See table 3. The OCR has passed the test if the indicated value falls within the range of setting ±20 ms.
7) Return the current adjusting knob to the MIN position. See Fig. 1.
8) Press the reset switch. See Fig. 1. "0" will be indicated on the display of the OCR checker.

5-6. Testing Procedure for Trip Current Setting Value for Instantaneous
Trip Function
1) Criterion value
(For TemBreak)
Calculate the criterion value as follows:
IT = I3 / ICT × 50 (mA)

I3: Instantaneous trip pickup current setting (A)

IT: Current flowing through the OCR (mA)
ICT: CT rated primary current (A) *10
*10: The CT rated secondary current is 50 mA.

(For TemBreak2)
Select the criterion value from Table 5 of Page 22 and 23.

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KRB-5308b
 Table 5-1 Criterion value for Instantaneous Trip Function (1)
Breaker Rated Current Setting value of rated current Criterion value for Instantaneous
Types [A] adjustment dial for Breakers Trip function [mA]
S250-NE 40 0.4 560
S250-GE 0.5 700
S250-PE 0.63 882
H250-NE 0.8 1098
0.9 1184
0.95 1196
1 1196
125 0.4 560
160 0.5 700
250 0.63 882
0.8 998
0.9 1090
0.95 1105
1 1105
S400-NE 400 0.4 560
S400-GE 0.5 700
H400-NE 0.63 882
L400-NE 0.8 1081
0.9 1197
0.95 1209
1 1209
S800-NE 800 0.4 630
0.5 200
0.63 400
0.8 800
0.9 225
0.95 450
1 900
S1000-NE 1000 0.4 560
0.5 672
0.63 829
0.8 885
0.9 885
0.95 885
1 885

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KRB-5308b
Table 5-2 Criterion value for Instantaneous Trip Function (2)
Breaker Rated Current Setting value of rated current Criterion value for Instantaneous
Types [A] adjustment dial for Breakers Trip function [mA]
S1250-NE 1250 0.4 560
S1250-GE 0.5 700
0.63 856
0.8 1047
0.9 1107
0.95 1107
1 1107
S1600-NE 1600 0.4 532
0.5 641
0.63 767
0.8 938
0.9 996
0.95 996
1 996

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KRB-5308b
 2) Set the element selector switch to the INST-I ◯
5 position. See Fig. 1.

3) Turn the current adjusting knob a bit clockwise from the MIN position. See Fig. 1
4) Press the start switch to start energization. See Fig. 1. *11
*11: ◯ 1 The duration of energization is as short as approx. 50 ms. The current turns off

automatically after such a duration of time and the display of the OCR checker provides
indication of the value of current applied.
2 Repeat the following steps to increase/decrease the current:
◯
1) Press the reset switch.
2) Use the current adjusting knob to adjust the current. See Fig. 1.
3) Press the start switch. See Fig. 1.
4) Check the current flowing through the OCR.
3 Turning off the breaker will facilitate adjusting the current.
◯
If the breaker is on while the current is adjusted, RESET and then ON operation will be
required after the breaker trips open.

5) The breaker will trip open when the current flowing thought the OCR exceeds the trip pickup current setting. The
NORMAL lamp will turn on and the display provide indication of the instantaneous trip pickup current setting. See
Fig. 1.
6) Compare the INST trip pickup current indicated on the display of the OCR checker with the criterion value calculated
in step 1) aboveThe OCR has passed the test if the indicated value falls within the range of criterion value ±20%. *12
*12: For TemBreak, saturation characteristics of the built-in CT may cause larger measurement error
when the instantaneous trip pickup current (I2) is set to the max value.

7) Return the current adjusting knob to the MIN position. See Fig. 1.
8) Press the reset switch. See Fig. 1. "0" will be indicated on the display of the OCR checker.

5-7. Testing Procedure for Trip Current Setting Value for Ground Fault Trip
Function
1) Criterion values for the ground fault trip pickup current are shown in table 6 below:
Table 6 Criterion values for ground fault trip pickup current
Breaker Setting Criterion value (mA)
TemBreak IG dial position 0.1 23
(0.15)*13 36
0.2 49
*13
(0.25) 62
0.3 75
*13
(0.35) 87
0.4 100
TemBreak2 ICT × 0.2 (fixed) 20
*13: Values in parentheses "( )" are intermediates between calibration marks.
2) Set the element selector switch to GROUND FAULT-I ◯ 6 position. See Fig. 1.

3) Press the start switch to start energization. See Fig. 1.

4) Turn the current adjusting knob clockwise gradually. See Fig. 1.
5) The breaker will trip open when the current flowing thought the OCR exceeds the trip pickup current setting. The
NORMAL lamp will turn on and the display provide indication of the ground fault trip pickup current setting. See Fig.
1.
6) Compare the GF trip pickup current indicated on the display of the OCR checker with the criterion value calculated in
step 1) above. The OCR has passed the test if the indicated value falls within the range of criterion value ±15%.
7) Return the current adjusting knob to the MIN position. See Fig. 1. *14
This step is not required if this test is followed by a test for GF trip pickup timing.

8) Press the reset switch. See Fig. 1. "0" will be indicated on the display of the OCR checker.

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KRB-5308b
5-8. Testing Procedure for Trip Time Setting Value for Ground Fault Trip
Function
If the ground fault trip function is selected, the OCR operates at a definite time when the current flowing through the OCR
exceeds the trip pickup current setting. During a test for ground fault trip timing, approx. 120% of the ground fault trip pickup
current setting is applied to the breaker.

1) Turn the current adjusting knob a bit more clockwise than for the test in section 5.3. See Fig. 1.
2) Set the element selector switch to GROUND FAULT-T ◯ 7 position. See Fig. 1.

3) Press the start switch to start energization. See Fig. 1. *15

*15: The current turns off automatically approx. 1500 ms after the start of energization.

4) The breaker will trip open when the trip pickup time setting has elapsed. The NORMAL lamp will turn on and the
display provide indication of the GF trip pickup time setting. See Fig. 1.
5) Compare the GF trip pickup time indicated on the display of the OCR checker with the GF trip pickup time setting
(TG). The OCR has passed the test if the indicated value falls within the range of setting TG ±20%.
6) Return the current adjusting knob to the MIN position. See Fig. 1.
7) Press the reset switch. See Fig. 1. "0" will be indicated on the display of the OCR checker.

5-9. Adjustment
The type TNS-2 OCR checker is a mesuring instrument. It is recommended that adjustment be performed approximately once
for a correct testing. If adjustment is necessary, contact us.

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 26
KRB-5308b
Circuit Breaker Division
7-2-10 Kamihigashi, Hiranoku, Osaka 547-0002, Japan

Tel: 81-6-6791-9323 Fax: 81-6-6791-9274

Web Site: www.terasaki.co.jp E-mail: int-sales@terasaki.co.jp

Published in August 2006

Revised in June 2009

The contents of this manual may be subject to change without notice.

Recycle paper used.

KRB-5308b