AcreL 259 WHD Temperature and Humidity Controller

Product Information

The WHD Temperature & Humidity Controller is designed for adjustment and control of temperature and humidity in high voltage switchgear, terminal boxes, ring network panels, box transformer substations, and other equipment. It effectively protects the equipment from faults caused by extreme temperatures, creepage, flashover, humidity, or condensation. This product meets the requirements of GB/T 15309-1994.

The controller consists of a transmitter, a controller, and a heater or fan. It can be configured with different control functions and has options for RS485 communication, alarming output, and transmitting. The WHD Temperature & Humidity Controller is available in different sizes and panel types. Technical parameters include measuring range, precision, transmitting output, set range of controlling parameters, output contact capacity, communication port, auxiliary power, voltage consumption, insulation resistance, power-frequency withstand voltage, average work time without stoppage, and working conditions.

Product Usage Instructions

1. Ensure that the controller is installed in a suitable location where it can effectively monitor temperature and humidity.
2. Connect the appropriate temperature and humidity sensors to the controller based on the model (WHD48, WHD72, WHD20R, or WHD46) being used. Refer to the user manual for the specific number of sensors allowed for each model.
3. If required, connect the heater and fan to the control output contacts of the controller. The heater is used for temperature rising or moisture removal, while the fan is used for temperature decreasing.
4. If applicable, configure the auxiliary functions such as RS485 communication, alarming output, and transmitting based on the requirements of your application.
5. Set the desired controlling parameters for temperature and humidity using the control panel or interface provided.
6. Ensure that the controller has a stable power supply within the specified voltage range. Check the power consumption and make sure it is within acceptable limits.
7. Verify the insulation resistance and power-frequency withstand voltage to ensure electrical safety.
8. Monitor the controller’s operation and adjust the settings as necessary to maintain the desired temperature and humidity levels.

Declaration

No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form by any means, electronic, mechanical photocopying, recording， or otherwise without prior permission of AcreL. All rights reserved. This company reserve power of revision of product specification described in this manual, without notice. Before ordering, please consult local agent for the latest specification of product.

General

The controller for temperature and humidity is suitable for adjustment and control of temperature and humidity in equipments of high voltage switchgear, terminal box, ring network panel, box transformer substation etc. It can effectively protect relevant equipment from faults resulting from excessive low or high temperature, creepage or flashover etc.from humidity or condensation. These products meet the requirements of GB/T 15309-1994.

Operational principle

The controller for temperature and humidity mainly consists of three parts of transmitter, controller, heater(or fan etc.), its operational principle is shown as following:

The message of temperature and humidity in the box is detected by the sensor and analyzed by the controller: When environmental temperature, humidity is up to the presetting value or exceed the presetting value, the controller is giving related signal to contacts of the relay, then the heater(or fan) is energized and working to heat of dehumidifying; after environmental temperature, humidity is well below the presetting value,the heater(or fan) is energized and stop working. In addition to its basic functions, the specific product with different type possesses secondary functions such as alarming output for wire-breaking, communication,forced heating etc.

Type explanation

Note

1. Number 0f temperature, humidity(or temperature) sensor to be connected with WHD48, WHD72. WHD20R, WHD46 is up to 1,2, 3 respectively;
2. Every sensor match with two control output contacts(passive), connected with heater and fan respectively, the heater is used for rising temperature or removing moisture, the fan is used for decreasing temperature;
3. Auxiliary function of WHD46:R$485 communication, alarming output function and transmitting function. Only one can be selected.
   • Auxiliary function of WHD48:RS485 communication.
   • Auxiliary function of WHD72:Alarming output function,RS485 communication and transmitting function. The latter two can only be selected.
   • Auxiliary function of WHD2OR:RS485 communication and alarming output function. Both can be selected at the same time.
   • – C” for communication,” -J” for alarming,” -M” for transmitting.
4. The connecting wire between sensor and controller must use a four-core shielded cable. And its maximum length must not exceed 20 m.

Technical parameter

Measuring range

| Temperature| -40.0℃～99.9℃
Humidity| 0%RH～99%RH

Precision

| Temperature| ±1℃
Humidity| ±5%RH
Transmitting output| DC 4～20mA 或 DC 0～20mA

Set range of controlling parameter

| Heating for

Temperature rising

|

-40.0℃～40.0℃

Blowing for

temperature decreasing

|

0.0℃～99.9℃

Humidity control| 20%RH～90%RH
output contact capacity| 5A/AC250V
Start/stop gap| 5
Communication port| RS485,MODBUS(RTU)协议

Auxiliary power

|  |

Voltage

| AC 85～265V

DC 100～350V

 |

Consumption

| Basic power consumption(≤0.8w)；

relay power consumption(each channel≤0.7w)

power-frequency withstand voltage

| power with shell, touchable metal parts/

power with other terminal group 2kV/1min(AC,RMS)

average work time without stoppage| ≥50000h

Working condition (controller)

| Temperature| -20℃～+60℃
Humidity| ≤95%RH， without condensation and corrosive gas
Altitude| ≤2500 m

Start/stop gap: In the control process,for the execution part (heater or fan) , the difference between starting temperature( humidity) and stopping temperature (humidity).

Product specification and functions

WHD48 Type with auxiliary function:signal communication”-C”

WHD48-11

| One channel temperature, humidity control|

WH-3(1)

|

Embedded catout：45×45

|

WHD48-22

|

Two channel temperature, humidity control

|

WH-3(1)

WH-3T(1)

WHD46 Type with auxiliary function:fault alarm”-J”,signal communication”-C”,transmission”-M”

WHD46-11

| One channel temperature,

humidity control

| WH-3(1)| Embedded catout：116×56|

WHD46-22

| Two channel temperature,

humidity control

| WH-3(2)
WHD46-33| | WH-3(3)

WHD72 Type with auxiliary function:fault alarm”-J”,signal communication”-C”,transmission”-M”

WHD20R Type with auxiliary function:fault alarm”-J” ,signal communication”-C”,both are optional

WHD20R-11

| One channel temperature, humidity control| WH-3(1)| guide rail typ： DIN35mm|

WHD20R-22

| Two channel temperature, humidity control| WH-3(2)

Wiring mode

WHD48 Type

WHD72 Type

WHD20R Type

WHD46 Type

An example of wiring for the communication part is shown below:

• Correct wiring method:the communication cable shield is connected to the ground.
• It is recommended to add a matching resistor between A and B of the end meter,and the resistance range is 120 Ω-10KΩ.

Product operation manual

Display introduction

Front diagram

Legend explanation

1

| temperature Area

Temp.area

|

XX.X℃

| Display current-measured temperature value,range:-40.0℃～

99.9℃ Display menu and data for keystroke programming

2| Channels| X| Display current-measured channels,rang：1～3

3

| humidity Area

Humidity area

|

XX%

|

Display current-measured humidity value,range：20%～90%

---|---|---|---

4

|

Working status

| Indicator

lightering

| Working state of    1,2,3,channels,heating    (HEAT),

Blowing    (FAN),fault of heating (BREAK)

5| SET| Pressing| Selecting operational function,set up programming

6

|

Left directional key

| Pressing| Look over data or change data
Keep

Pressing

|

Keep Pressing the key about 3 seconds,all channels are in heating

7

|

Right directional key

| Pressing| Look over data or change data
Keep

Pressing

|

Keep Pressing the key about 3 seconds,all channels are in blowing

8| ENTER key| Pressing| Confirm function or go to next menu

System powered

• After wiring correctly according to the instraction，power on and enter into the measuring condition.

Working status

Measurement

• Under measuring condition , Area 1, 2, 3 display currently: measuring channel and temperature value，humidity value , temperature value,humidity value circling measurement and display of three sensor’s channels.

Control

When environmental temperature value or humidity value satisfy the presetting working condition , starting the heater or fan, while corresponding indicator lights (Area4) , when the heater is failure, working without as per the normal working condition, the corresponding indicator for heating-fault lights to give alarming.

Control test

• Under the normal working condition, hold pressing the left directional key about 3 seconds,all the allowed channels are in heating; hold pressing the right directional key over 3 seconds,all the allowed channels are in blowing .

Alarm

• When the heater is failure,working without as per the normal working condition, the corresponding indicator for heating-fault lights to give alarming.
• when the temperature exceeds the set value,the data of corresponding channel flashes. Reset when the meter itself fails.

System setting mode

Entry/exit system setting mode

• Under the normal working condition，hold pressing the SET key about 3 seconds,entry in system setting mode, stroke ENTER and input the pass words , the deliver default value as 0000, if pass words is correct (display YES ) , enter into the main menu automatically.
• After enter into the main menu , Area 1 display “CH1”, stroke ENTER, enter into the working parameter setting of channel 1, press the left/right key to switch to other menu with same level, this level menu has “CH2”, “CH3”, “COMM “,”DISP”，”CTRL”，”VErn”,setting up working parameter of channel 2, channel 3,communication, display mode, look over software version respectively.

Setting channel parameters

The parameter setting process of CH1, CH2,CH3 is one and the same. Taking CH1 as example , to explain clearly: After setting entry system, menu and data display in Area 1 , after setting entry channel, Area 2 display channel sequence number. Display before entry in.CH1:

Single click ENTER the display as follows:

1

|

ON

| Allow channel 1,selecting left/right key for “on”/”off”,click ENTER for confirm

2

|

1

| Current setting is the first channel

Selecting “on”，Single click ENTER the display as follows

1

|

H.dry

| Single click ENTER for entry, setting humidity value for starting process of heating and removing moisture

2

|

1

| Current setting is the first channel

Single click ENTER the display as follows

1

|

85

| Single click left/right key for revising , hold pressing for increasing/decreasing of quickly, click ENTER for confirm

2

|

1

| Current setting is the first channel

Single click ENTER the display as follows

1

|

HEAt

| Single click ENTER for entry, setting temperature value for starting process of heating and temperature rising

2

|

1

| Current setting is the first channel

Single click ENTER the display as follows

1

|

5.0

| Single click left/right key for revising , hold pressing for increasing/decreasing of quickly, click ENTER for confirm

2

|

1

| Current setting is the first channel

Single click ENTER the display as follows

1

|

ALM.H

| Single click ENTER , setting ifopen heating-fault alarm

2

|

1

| Current setting is the first channel

Single click ENTER the display as follows

1

|

OFF

| selecting left/right key for “on”/”off”,click ENTER for confirm

2

|

1

| Current setting is the first channel

Single click ENTER the display as follows

1

|

FAn.C

| Single click ENTER , setting temperature value to start blowing-reducing temperature

2

|

1

| Current setting is the first channel

Single click ENTER the display as follows

1

|

40.0

| Single click left/right key for revising , hold pressing for increasing/decreasing of quickly, click ENTER for confirm

2

|

1

| Current setting is the first channel

Single click ENTER the display as follows

1

|

HYS.H

| Single click ENTER for entry, setting hysteresis value of heating to remove moisture

2

|

5

| Single click left/right key for revising , click ENTER for confirm

1

|

HYS.d

| Single click ENTER for entry, setting hysteresis value of heating to remove moisture

2

|

5

| Single click left/right key for revising , click ENTER for confirm

1

|

HYS.U

| Single click ENTER for entry, setting hysteresis value of heating to remove moisture

2

|

5

| Single click left/right key for revising , click ENTER for confirm

Single click the Enter, return the main menu, use left/right key to select other main menu and setup the optional item. The communication “COMM”may set up Local address ( 1～247) and Communication baud rate value (1200, 2400,4800,9600,19200) . The display mode”dISP” is used to set three channels: interval in circling measurement display; closed circling or interval for 2s,4s,6s,8s. AI random position of main menu ,single click SET to select storage or not and exit system setting, then return back normal working mode.

Set up system password

• Press SET and ENTER simultaneously about three seconds, display: “CodE”, Single click ENTER for entry, type current system password. Single click ENTER to confirm the typed password, the correct password display “yES”,and switch to “n.Cod” automatically, single click entry to type new password, press ENTER to select storage or not, then to exit..
• At random setting position, if within 1 minutes, no effective key is pressed, the system return to measuring status automatically the setting is not stored.

User’s Programming flow diagram

frequency interval

ALM.H| Heater alarm for broken wire| VErn| Version No. of software
Fan.C| Blow to reduce temperature| n.Cod| Typing password
Hys.H| Hysteresis value of heating to remove

moisture

| SAVE| Storage
Hys.d| Hysteresis value of heating to rise

temperature

| ruPt| Sensor failure
Hys.U| Hysteresis value of blow to reduce

temperature

| SEL| relevant output select
tr.1/tr.2| Deliver access programming| tr.Lo| programming low
tr.Hi| programming high|  |
CTRL| Forced heating/blowing time setting| x.xH| Time , 0.0H: Keep on

Communication manual

Communication

This chapter mainly explains how to use software to operate this series meter by communication interface. You are required to obtain the knowledge of MODBUS protocol and have general comprehension of the meter’s function and application after reading through out other content of this manual. The content of this chapter includes: brief introduction of MODBUS protocol, detailed explanation of communicate application format,application details of the meter and parameter address table.

MODBUS Communication

WHD Series Intelligent Temperature & Humidity Controller. MODBUS protocol defines detailedly checkout code, data sequence and so on which are necessary content of specific data change. MODBUS protocol uses half duplex connection mode in one communication wire. That means signals of a separate wire transfer along contrary direction. Firstly,signal of host computer seeks address to a exclusive terminal unit,then terminal unit sends out responding signal that is transmitted to the host computer with contrary direction. MODBUS protocol only allows communication between mainframe(PC, PLC etc.) and terminal unit, it doesn’t permit data change between separate terminal equipment. Each terminal unit will not occupy communication wire while initializing, it only responses to rogatory signal itself.

Searching-responding period

Searching

Function code of searching information tells the selected slave unit should carry out which kinds of function. Data segment includes any addition information that the slave unit will operate the function. For example, function code 03 required reading keep register from slave unit and returning their content. Data segment should contain the information that will be sent to slave unit: read from which register and the number of Register.Error detecting region supplies slave unit with a method that can validate if the information content is correct.

Responding

If the slave unit brings a normal response,function code of the response information is the response of function code in searing information.Data segment includes collecting data of slave unit: such as register value or state. If error occurs, function code will be amended to indicate the response information is wrong, meanwhile, data segment contains the code which describes this error. Error detecting region allows main unit affirm if the information is usable.

Transmit mode

• Transmit mode is a series of data configuration in a data frames and finity rule used for data transmission.
• Transmit mode that is compatible with MODBUS protocol-RTU mode is defined as follows.

Bit of each byte

• 1 start bit
• 8 data bits, the minimal efficient bit delivering first
• No parity check bit
• 1 stop bit

Error checking: CRC(circle redundancy check)

Protocol

When data frame reaches terminal unit, it enters searching addressed unit from a simple “port” .The unit takes out the “envelop” (data head) and reads data, then carries out mission required by data if there is no error.After that, the unit adds the produced data to “envelop” and returns data frame to sender. Response data returned includes: Address of terminal slave unit, Function carried out, Data produced and a Check. There is no successful response if any error occurs, or return to a false frame.

Data frame format

Address region

Address region which is the beginning of frame consists of a byte( 8 bits binary code). The decimalist is 0-255, and the system uses 1-247. The bits indicate address of terminal unit appointed by users which acquire data from the connected host computer. Address of each terminal unit must be exclusive, and the address searched terminal will bring address search. When terminal returns a response, slave address data of response tells host computer with which terminal is communicating.

Function region

Function region code tells the address searched terminal which function to carry out. Function codes used in meter are as follows.

register
16| Preset multi-register| Set binary value to series of multi-register

Date region

• Data region includes the data which terminal needed to carries out specific function or which is sampled when terminal responses searching.
• The content of data maybe numerical value, reference address or setup value. For example: Function

Error-checking region

Check region allows error between host computer and terminal transmission. Sometimes because of electrical noise and other disturbance，a set of data may change while transmitting from one unit to another,error- checking can assure host or terminal not to answer the changed data.It improves the security and efficiency of system. Error-checking adopts CRC16 method.

Protocol

CRC region occupies 2 bytes, binary value 16 bits. CRC value is accounted by transmit unit,then adds to data frame. Receiver unit accounts CRC value again while receiving data, then compares with the value of CRC region.If the two are unlikeness, there is an error.

While CRC operating，Preset 16 bits register 1 beforehand, then operate the 8 bits of each byte in data frame and current value of register Continuously.Only 8 data bits of each byte participate in creating CRC, which is not influenced by start bit, stop bit and parity bit. While creating CRC. 8 bits of each byte exclusive OR with the content in register. The result is moved to low bit, “0” is used in high bit. LSB moves out and will be detected, if 1, the register carries out a exclusive OR operation with a preset fixed value(OA001H), if the lowest bit is 0, do nothing. Operation above carries repeatedly till 8 bit moving is completed. When the last bit moves，next 8 bits carries out exclusive OR operation with current value of register. while operating another said 8 bit moving exclusive OR operation. AII bytes are operated, CRC value is the final value.

Flow to create a CRC:

• Preset a 16 bits register OFFFFH beforehand,which is called CRC register.
• The 8 bits of first byte in data frame carries out exclusive OR operation with the low byte in CRC register and store the result in CRC register.
• Move CRC register one bit to right, define the highest 0, move out the lowest and check it.
• If the lowest bit is 0, repeat step 3; if is 1, the register carries out a exclusive OR operation with a preset fixed value (OA001H)
• Repeat the step 3 and 4 till the eighth moving. A whole 8 bits is transacted.
• Repeat step 2 to 5 to deal with next 8 bits till all bytes to be transacted.
• CRC value is the final CRC register value.

In addition, there is a way to account CRC by presetting a table beforehand. The main characteristic is speediness of account, but the table needs biggish storage space.

Communication format explanation

Examples as follows is used as tables (hexadecimal).

Addr| Fun| Data start reg hi| Data start reg lo| **Data

of reg hi| Data #of reg lo| CRC16 lo| CRC16 hi**

---|---|---|---|---|---|---|---
01H| 03H| 00H| 00H| 00H| 03H| 05H| CBH

Reading( function code 03 or 04)

Searching data frame

This function allows user acquire system parameter and data of sampled and recorded by unit. It is not limited for data number of required by host computer but can’t beyond the defined address range. The following example show that from 01 slave computer to read two collected basic data reading, CH1 temperature value and humidity value, address of temperature value is 0003H，address of humidity value is 0004H， both length is 2 byte.

Addr| Fun| Data start reg hi| Data start reg lo| **Data

of reg hi| Data #of reg lo| CRC16 lo| CRC16 hi**

---|---|---|---|---|---|---|---
01H| 03H| 00H| 01H| 00H| 02H| 95H| CBH

Response data frame

Response includes slave computer address,function code,byte length of data,data and CRC error-checking. Following example is response of reading CH1 temperature,humidity value.

Addr| Fun| Byte count| Data1 hi| Data1 lo| Data 2 hi| Data2 lo| CRC16 lo| CRC16 hi
---|---|---|---|---|---|---|---|---
01H| 03H| 04H| 01H| 20H| 02H| 5EH| 7AH| 9DH

• temperature= (0120H )/OAH = 288/10 = 28.8℃
• humidity= (025EH)/OAH = 606/10 = 60.6%

The address table for reading parameters is shown as follows

Addr| Data Content| Data type| Read/Write| Command word| Note
---|---|---|---|---|---

0

| Working condition:bit0～bit3 are the first ways Working condition:bit 4 ～ bit7 are the second ways

Working condition:bit8～bit11 are the third ways Bit0 Heater status 0=normal 1=fault

Bit1 Sensor status 0=normal 1=fault Bit2 Heating status 0=cease 1=heating

Bit3 Blast state 0=cease 1=blast

|

Unsigned int

|

R

|

03、04

|

0～4095

1| Temperature value measured in channel 1| signed int| R| 03、04|
2| Humidity value measured in channel 1| signed int| R| 03、04|
3| Temperature value measured in channel 2| signed int| R| 03、04|
4| Humidity value measured in channel 2| signed int| R| 03、04|
5| Temperature value measured in channel 3| signed int| R| 03、04|
6| Humidity value measured in channel 3| signed int| R| 03、04|

7

|

Meter communication address

| Unsigned

int

|

R/W

|

03、04 / 16

|

1～247

8

|

Meter communication baud rate

| Unsigned

int

|

R/W

|

03、04 / 16

| 0～4 show 1200～19200

respectively

9

| Alarm permission and channel permission bit0～bit1 are the first ways

bit2～bit3 are the second ways

bit4～bit5 are the third ways

bit0 fault detection of the first heater: 0 permit 1 prohibit

Bit1 is the first channel open :

0 permit  1 prohibit

|

Unsigned int

|

R/W

|

03、04 / 16

|

0～63

10

|

Meter display mode

| Unsigned

int

|

R/W

|

03、04 / 16

| Cycling      time(S),0FFH

indicate non-cycling

11| Temperature set for blowing in channel 1| signed int| R/W| 03、04 / 16| 0～1000
12| Humidity set for heating in channel 1| signed int| R/W| 03、04 / 16| 10～999
13| Temperature set for heating in channel 1| signed int| R/W| 03、04 / 16| -400～1000

14

|

Hysteresis value in channel 1

| Unsigned

int

|

R/W

|

03、04 / 16

|

1～40(low byte)

15| Temperature set for blowing in channel 2| signed int| R/W| 03、04 / 16| 0～1000
16| Humidity set for heating in channel 2| signed int| R/W| 03、04 / 16| 10～999
17| Temperature set for heating in channel 2| signed int| R/W| 03、04 / 16| -400～1000

18

|

Hysteresis value in channel 2

| Unsigned

int

|

R/W

|

03、04 / 16

|

1～40(low byte)

---|---|---|---|---|---
19| Temperature set for blowing in channel 3| signed int| R/W| 03、04 / 16| 0～1000
20| Humidity set for heating in channel 3| signed int| R/W| 03、04 / 16| 10～999
21| Temperature set for heating in channel 3| signed int| R/W| 03、04 / 16| -400～1000

22

|

Hysteresis value in channel 3

| Unsigned

int

|

R/W

|

03、04 / 16

|

1～40(low byte)

23

|

Hysteresis of heating and cooling in channel 1

|

Unsigned int

|

R/W

|

03、04

| 1 ～ 40(The high byte is heating up,the low byte is  the  cooling  of air

blast)

24

|

Hysteresis of heating and cooling in channel 2

|

Unsigned int

|

R/W

|

03、04

| 1 ～ 40(The high byte is heating up,the low byte is  the  cooling  of air

blast)

25

|

Hysteresis of heating and cooling in channel 3

|

Unsigned int

|

R/W

|

03、04

| 1 ～ 40(The high byte is heating up,the low byte is  the  cooling  of air

blast)

Preset multi-register (Function code 16)

Searching data frame

The temperature value set for starting the heater in Channel 1 is 5℃ , its register address is 0012H.

Delivered by host computer:

Addr| Fun| Data start reg hi| Data start reg lo| Data of reg Number Hi| Data of reg Number Lo| Data long| Data hi| Data lo| CRC16 lo| CRC16 hi
---|---|---|---|---|---|---|---|---|---|---
01H| 10H| 00H| 0DH| 00H| 01H| 02H| 00H| 32H| 26H| 98H

Response data frame

Addr| Fun| Data start reg hi| Data start reg lo| Data of reg Number Hi| Data of reg Number Lo| CRC16 lo| CRC16 hi
---|---|---|---|---|---|---|---
01H| 10H| 00H| 0DH| 00H| 01H| 90H| 0AH

APPENDIX

Sensor

General

The sensor of WHD Series Intelligent Temperature & Humidity Controller adopt external connecting mode, and special housing with advantages of good ventilation, aesthetic appearance, protect inner component effectively，boost service life，easily mounting and wiring.

Type explanation

WHD Series Intelligent purpose temperature & humidity controller sensor:

V+、V-、CLK、Data is connected with the controller’s matched wiring terminal respectively.

| Guideway type

Fixed

|

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