Bulletin H-WHT

Series WHT Weather-Proof Humidity/Temperature Transmitter

®

Specifications - Installation and Operating Instructions

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The Compact Series WHT Weather-Proof Humidity/Temperature Transmitter is SPECIFICATIONS

designed to withstand the elements. A removable sintered filter protects the polymer Relative Humidity Range: 0 to 100% RH.
capacitance sensor from solid objects that may come in contact with the transmitter. Temperature Range: -40 to 140°F (-40 to 60°C).
The transmitter is available with 4 to 20 mA, or 0 to 10 VDC or 0 to 5 V output signals Accuracy, RH: ±3% 20-80% RH, ±4% @ 10-20%, 80-90%.
for both temperature and humidity or a passive thermistor for temperature. This Accuracy, Temp, Models with 4-20mA Temp. Output: ±0.9°F@ 72°F (±0.3°C @
transmitter is ideal for measuring outside air temperature and humidity levels for air 25°C).
handling economizer applications. Accuracy, Models with Passive Thermistor Temp Sensor: ±0.4°F @ 77°F
(±0.22°C @ 25°C ).
INSTALLATION Hysteresis, RH: ±1%.
Warning: Disconnect power supply before installation to prevent electrical shock and Repeatability, RH: ±0.1% typical.
equipment damage. Temperature Limits: -40 to 140°F (-40 to 60°C).
Storage Temperature: -40 to 176°F (-40 to 80°C).
Make sure all connections are in accordance with the job wiring diagram and in Compensated Temperature Range, RH: -4 to 140°F (-20 to 60°C). 4 to 20 mA
accordance with national and local electrical codes. Use copper conductors only. Loop Powered models: Power requirements: 10 to 35 VDC. Output signal: 4 to 20
mA. 0 to 10 V Output models: Power requirements: 15 to 35 VDC or 15 to 29 VAC.
Caution: Use electrostatic discharge precautions (e.g., use of wrist straps) during Output signal: 0 to 10 V @ 5 mA max. 0 to 5 V Output models: Power requirements:
installation and wiring to prevent equipment damage. 10 to 35 VDC or 10 to 29 VAC. Output Signal: 0 to 5V @ 5 mA max.
Response Time: 15 seconds.
Avoid locations where severe shock or vibration, excessive moisture or corrosive Electrical Connections: Removable screw terminal block.
fumes are present. NEMA Type 3S (IP54) housings are intended for outdoor use Drift: <1% RH/year.
primarily to provide a degree of protection against wind-blown dust, and rain. RH Sensor: Capacitance polymer.
Temperature Sensor: 4 to 20 mA output, solid state band gap. Passive output: 10K
Do not exceed ratings of this device, permanent damage not covered by warranty may @ 25°C thermistor (Dwyer curve A).
result. The 4 to 20 mA models are not designed for AC voltage operation.­ Housing Material: ABS.
Enclosure Rating: Designed to meet NEMA 3S (IP54).
Weight: 0.3oz (8.5g).
Agency Approvals: CE.

DWYER INSTRUMENTS, INC. Phone: 219/879-8000 www.dwyer-inst.com

P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A. Fax: 219/872-9057 e-mail: info@dwyermail.com
­ OUNTING
M Models with 0 to 5 V or 0 to 10 V RH Output, with or without 0 to 5 V or 0 to 10 V
The transmitter should be mounted with the sensor pointing downward to prevent Temperature Output
water collection in the housing. The integral mounting tab has two sets of mounting The 0 to 10 V output models may be powered with 15 to 35 VDC or 15 to 29 VAC. The
holes. The larger holes are for the suspension mounting and the smaller holes are 0 to 5 V models may be powered with 10 to 35 VDC or 10 to 29 VAC. Note the polarity
for surface mounting the transmitter to a wall. Please see Figure 1 and 2 for more when using DC power. The channels are common on the negative side. For RH and
information on both mounting methods.­ Temperature outputs, either or both may be used. The maximum load is 5mA (1K for 0
to 5 V, 2K for 0 to 10 V). Wire as shown in Figure 5.

TEMP. RECEIVER

1 2 3 4 5
+ –
+ –
RH RECEIVER
+ POWER
WIRING – SUPPLY

Figure 5

Models with 0 to 5 or 0 to 10V RH Output and a Passive Thermistor Temperature

Sensor
The 0 to 5 V or 0 to 10 V RH output is identical to the above model with a 0 to 5 V or
0 to 10 V temperature output. The required power supply and wiring of the RH output
is the same. The passive thermistor temperature sensor wires to terminals 4 and 5.
Wire as shown in Figure 6.

TEMP. SENSOR

1 2 3 4 5
+ –
RH RECEIVER
+ POWER
– SUPPLY
Figure 1 Suspension Mounting Figure 2 Surface Mounting
Figure 6

WIRING Checkout
Use maximum 18 AWG wire for wiring terminal. Refer to Figures 3-6 for wiring 4 to 20 mA Models:
information. Verify appropriate supply voltage. The transmitter requires a minimum of 10 and a
maximum of 35 VDC at its connection for proper operation. Choose a power supply
Models with 4 to 20 mA RH Output, with or without 4 to 20 mA Temperature with a voltage and current rating which meets this requirement under all operating
Output conditions. If the power supply is unregulated, make sure voltage remains within these
4 to 20 mA output units may be powered with a 10 to 35 VDC supply. The following limits under all power line conditions. Ripple on the supply should not exceed 100 mV.
describes the proper wiring of these transmitters with mA output.
Models with 4 to 20 mA RH and 4 to 20 mA Temperature outputs are designed as a Loop Resistance – The maximum allowable loop resistance depends on the power
4 to 20 mA device with two channels. The channels are common on the positive side supply voltage. Maximum loop voltage drop must not reduce the transmitter voltage
of the current loop. below the 10 VDC minimum. Maximum loop resistance can be calculated with the
Sensor excitation is derived from the relative humidity channel, so power must always following equation. Vps is the power supply voltage.
be applied to that channel. If the temperature channel is not equipped or used, it can
be left disconnected. Wire as shown in Figure 3. Rmax = Vps-10.0
20 mA
TEMP. RECEIVER Some receivers, particularly loop powered indicators, may maintain a fixed loop
1 2 3 4

+ – voltage to power the device. This voltage drop must also be subtracted from the power
+ POWER supply voltage when calculating the voltage margin for the transmitter. The following
+ – – SUPPLY equation takes this into account. Vrec is the receiver fixed voltage.
RH RECEIVER
Vps-10.0-Vrec
Figure 3 Rmax =
20 mA
Models with 4 to 20mA RH Output and a Passive Thermistor Temperature Sensor 0 to 5, 0 to 10 V Output Models:
The 4 to 20 mA RH output is identical to the above model with a 4 to 20 mA temperature Verify appropriate supply voltage. The 0 to 10 V output models require a DC supply of
output. The required power supply and wiring of the RH output is the same. The 15 to 35 V or an AC supply of 15 to 29 V for proper operation maximum. The 0 to 5 V
passive thermistor temperature sensor wires to terminals 3 and 4. Wire as shown in output models require a DC supply of 10 to 35 V or an AC supply of 10 to 29 VAC. Both
Figure 4. outputs may be loaded simultaneously with 5 mA.

TEMP. SENSOR
1 2 3 4

MAINTENANCE
+ POWER Upon final installation of the Series WHT Temperature/Humidity Transmitter and
+ – – SUPPLY the companion receiver, no routine maintenance is required. A periodic check of the
RH RECEIVER system calibration is recommended. The Series WHT is not field serviceable and
should be returned if repair is needed (field repair should not be attempted and may
Figure 4
void warranty). Be sure to include a brief description of the problem plus any relevant
application notes. Contact customer service to receive a return goods authorization
number before shipping.

This symbol indicates waste electrical products should not be disposed

of with household waste. Please recycle where facilities exist. Check with
your Local Authority or retailer for recycling advice.

©Copyright 2019 Dwyer Instruments, Inc. Printed in U.S.A. 2/19 FR# 443597-00 Rev. 1

DWYER INSTRUMENTS, INC. Phone: 219/879-8000 www.dwyer-inst.com

P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A. Fax: 219/872-9057 e-mail: info@dwyermail.com