TEMPERATURE/HUMIDITY TRANSMITTER - WALL (4-20 MA)
Description
The THW420 combination temperature/humidity transmitter is designed to meet applications that require local indication of both temperature and humidity in a single, aesthetically pleasing enclosure.
This device incorporates a 10K ohm (Ω) platinum RTD. The transmitter requires 24 VDC. The sensor provides an accurate and predictable
Dimensions |
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FRONT | 0.95" |
VIEW | (241mm) |
4.5" |
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(1143mm) |
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| Wall |
2.25" | 0.75" |
(572mm) | (191mm) |
| SIDE |
| VIEW |
2.75" |
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(699mm) |
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TOP VIEW |
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Specifications
Output | 4 to 20 mA |
Sensor | 10K Ω platinum RTD |
Supply Voltage | 24 VDC |
Tolerance of Resistance | ±1.5°F (±0.83°C) |
(Accuracy) | ±2% RH (from 15 to 95% RH) |
Response Time | 20 seconds for a 63% step |
Environmental Operating | 45°F to 96°F; 0 to 100% RH |
Range (Transmitter) | (7°C to 35°C); 0 to 100% RH |
Termination
The THW420 transmitter must be powered from a 24 VDC supply. The combination temperature/ humidity sensor is terminated as follows:
•The humidity transmitter requires a
•The temperature sensor also requires a three- wire termination. In most cases, it obtains power from the analog input to which it is connected and no external power is required.
Though interference from external sources is not a major problem with current transmitters, Liebert recommends separating the wiring from line voltage wiring and from wiring used to supply highly induc- tive loads such as motors, generators and coils. Lie- bert also recommends making power connections with twisted pair wire of at least 22 AWG and crimp- type connectors.
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| Controller | |
| SW2 OUTPUT SELECT | To GND (common) |
| Ground | ||||
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| ON |
| of controller* |
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| Ch1 |
| From +24VDC |
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| Ch2 |
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| Input #1 | ||||
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| of controller or |
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| + | ||
| RESIST. | Ch3 |
| power supply | To controller’s | |||
| RUN | %RH | CAL |
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| - | |
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| analog input | ||||
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| SW2 |
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| (temperature signal, | |
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| Input #2 | ||
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| + | |
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| C9 Gnd |
| Ch1 | Ch2 | To controller’s | |
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| V+ | - | ||||
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| X |
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| analog input |
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| (humidity signal, |
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| J2 |
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| DISPLAY CYCLE |
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| IN SECONDS |
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| * NOTE: |
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| 10 | J3 |
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| 20 | CAL | Temp | Temp | The GND (common) | |
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| H Ch3 | terminal is common | ||||
| POT1 |
| R19 |
| between the Power | |||
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| Building Automation |
| T&B | and Sensor |
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| U3 | Products, Inc. |
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| Copyright 2000 |
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| SWITCH |
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| REV. 101600 |
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| XCOMBO T&B | Short |
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| J1 |
| Norm |
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| Open |
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| SW1 | +24VDC should be | |
| RTH1 RTH2 |
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| used at all times | |||
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| Terminations |
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! | CAUTION |
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| Liebert recommends wiring the sensor |
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| WITHOUT power applied because |
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| accidental arcing may damage the product | |||||||
| and will void the warranty. |
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Ordering Information
Quantity | Part # | Description |
THW420 Combination Temperature/Humidity Transmitter Wall
page 1 | 6/03 (Rev. 0) |