Dwyer Instruments THC Operating Manual

• Dependent ON/OFF control

If rh8=ono and rh0=dEP, output 3 works as in Independent ON/OFF
control, but output 4 works as follows:
If ch3=dir, output 4 will connect when HS >= Sh1+Sh2+rh2 and will
disconnect when HS <= Sh1+Sh2.

Humidity

Sh1+Sh2+rh2

Sh1+Sh2

Output 4 ON

ch1

Time

If ch3=Inv, output 4 will connect when HS <= Sh1+Sh2-rh2 and will
disconnect when HS >= Sh1+Sh2.
ch1 is the minimum stop time.

Humidity

Sh1+Sh2

Sh1+Sh2-rh2

Output 4 ON

ch1

Time

• Neutral zone control

If rh8 = NEu output 3 connects when HS >= Sh1+rh3 and
disconnects when HS <= Sh1, while output 4 connects when Hs1
<= Sh1-rh3 and disconnects when HS >= Sh1.

Humidity

Sh1+rh3

Sh1

Sh1-rh3

Output 3 ON

Output 4 ON

Time

• Control with probe errors

If reading of humidity probe fails the output 3 works following 10
minutes cycles, with a percentage of connection time given by Ch4.
Output 4 is carried out in the same way with parameter Ch5.

• Humidity alarms

If HS >= Sh1+Ah1, the controller will indicate maximum humidity
alarm for (AHH) and the alarm will remain activated until HS <=
Sh1+Ah1-Ah0.
If HS <= Sh1-Ah2, the controller will activate minimum humidity
alarm for (ALH), and it will remain activated until HS >= Sh1-Ah2­Ah0.
Program Ah3 to indicate the alarm check time between alarm
event and indication of an alarm event. The alarm is indicated by
a message on the display and activating the alarm output if
present (alarm can be silenced pressing UP+DOWN keys or
CLEAR in the IR remote control).

Humidity

Sh1+Ah1

Sh1+Ah1-Ah0

High Alarm ON

Humidity

Sh1-Ah2

Sh1-Ah2+Ah0

Low Alarm ON

• Probe options

If the probe is not placed in the exact point to control, use a
standard hygrometer to determine the offset and set it by Ph0.

Set Ph1 to select if the decimal point is shown or not in the
display.
Set Ph2 to set the probe type (0-1V, CRPH03 or 4-20mA).
If a 4-20mA probe is used, use Ph3 to set the humidity value
for 4mA and Ph4 to set the value for 20mA.

General parameters

H1,H2,H3 are general parameters that can be accessed from
both temperature and humidity parameters.
Setting H1 to yES the set points (St1,St2,Sh1,Sh2) cannot be
changed. To unblock this protection, press SET T or SET H for 8
seconds and introduce the code in the same way as is done when
entering parameters.
H2 sets the communication address for the controller.
H3 sets the access code to parameters.

Led indication and display messages

The four OUT leds indicate the of the four outputs (when the
correspondent led is ON the output is connected and when the
led is OFF the output is disconnected).

In normal operation, the left display will show the temperature
measured by probe 1 and the right display the relative
humidity. In order to display the temperature measured by
probe 2 press SET T + UP keys.

In case of alarm or error, the following messages can be
shown:

• Err = Memory reading error

• ErP = Error in the temperature probe 2

• AHt = High temperature alarm (probe 1)

• ALt = Low temperature alarm (probe 1)

• AHh = High humidity alarm

• ALh = Low humidity alarm

• ooo = Open Probe Error

• --- = Short Circuit Probe Error

Maintenance, cleaning and repair

After final installation of the unit, no routine maintenance is
required.

Clean the surface of the display controller with a soft and damp
cloth. Never
use abrasive detergents, petrol, alcohol or solvents.

All repairs must be made by authorised personnel.

THC Series Temperature and Humidity Controller

Specification and Operating Instructions

Description

The THC is a temperature and humidity digital controller. The
temperature control can be ON-OFF, neutral zone and refrigeration
modes. It is possible to set a second temperature probe for
defrosting control. Humidity control can be ON-OFF and neutral
zone modes. The humidity probe can be 0-1V, 0-3V THC-P and 4­20mA types.

Model references

The model reference is given by: THC-YZ

Each sufix can take the following values:

Y Supply Voltage 1=115VAC, 2=230VAC
Z Temp. Units 0=ºF, 1=ºC

Installation

NOTE: Unit must be mounted away from vibration, impacts, water
and corrosive gases.

•

Cut hole in panel 131 .15 x 3.97 inches).

Remove the rear cover to wire the unit.

•

The wiring diagram is shown in the unit label.

•

•

Apply silicone (or rubber gasket) around the perimeter of the hole

to prevent leakage.

•

Insert the unit in the panel hole.
Replace the rear cover.

•

•

Place removable fitting clips from the back of the until it is secured

to the panel.

•

Fit the clip in the panel and then press to fit the other side in the

unit.

x 101 mm (5

Wiring Diagram

OUT4 OUT3 OUT2 OUT1

RX TX GND IN VCC

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

tº

SUPPLY

tº

Sd1 Sd2 SH

Technical Data

Supply voltages 115 VAC10%, 230 VAC10%

Supply powers 7VA (230V)

Storage temperature -20ºC to 80ºC (-4 to 176ºF)

Operating temperature 0ºC to 70ºC (32 to 158ºF)

Temperature probe PTC1000 (25ºC - 1000 Ohm)

Temperature probe range -50ºC to 150ºC (-58 to 302ºF)

Temperature accuracy Better than 0,5

Temperature resolution

0.1º (3 digits)

Humidity probe 0-1V, 0-3V THC-P 4-20mA

Humidity probe range 0 to 100% RH

Humidity accuracy Better than 5

Humidity resolution 1% (3 digits)

Displays 3-digit and sign (x2)

Outputs SPDT relay 250Vac 8A RL

Dimensions 134x105x61mm (5.3x4.1x2.4 in)

Front Protection IP65

% of full scale

,

% of full scale

%H

LOVE CONTROLS DIVISION Phone: [phone] www.love-controls.com
DWYER INSTRUMENTS, INC. Fax: [phone] e-mail:[e-mail]
P.O. BOX 338 - MICHIGAN CITY, Lit-By Fax: [phone]
INDIANA 46361, U.S.A.

ETDT1076L_060705 ETDT1076L_060705

Temperature Probe 1 (Sd1) in terminals 18 - 17
Temperature Probe 2 (Sd2) in terminals 19 - 17
Humidity Probe (SH) in terminals 20-21-17

•

Note: DO NOT INSTALL PROBE CABLES NEAR POWER

CABLES.

LOVE CONTROLS DIVISION Phone: [phone] www.love-controls.com
DWYER INSTRUMENTS, INC. Fax: [phone] e-mail:[e-mail]
P.O. BOX 338 - MICHIGAN CITY, Lit-By Fax: [phone]
INDIANA 46361, U.S.A.

List of temperature parameters

Description Units Range

St1 Temperature set point 1 Degrees rt4 to rt6
St2 Temperature set point 2 Degrees rt5 to rt7
rt0 St1 and St2 dependency Range Ind / dEP
rt1 Differencial for St1 Degrees 0.1 to 20.0
rt2 Differencial for St2 Degrees 0.1 to 20.0
rt3 Band differencial Degrees 0.1 to 20.0
rt4 Minimum value for St1 Degrees -99.9 to rt6
rt5 Minimum value for St2 Degrees -99.9 to rt7
rt6 Maximum value for St1 Degrees rt4 to 302
rt7 Maximum value for St2 Degrees rt5 to 302
rt8 Operation mode Range ono/rEF/nEU
dt0 Defrosting type Range fRES/InV
dt1 Max. defrosting temperature Degrees -99.9 to 302
dt2 Max. defrosting time Minutes 0 to 240
dt3 Defrosting interval time hh:mm 0.0 to 18.0
dt4 Defrosting displayed temp. Range off/on/-d­At0 Alarm differencials Degrees 0.1 to 20.0
At1 Maximum probe 1 alarm Degrees 0.1 to 99.9
At2 Minimum probe 1 alarm Degrees 0.1 to 99.9
At3 Alarm check time hh:mm 0.0 to 18.0
ct0 Minimum stop time output 1 Minutes 0 to 240
ct1 Minimum stop time output 2 Minutes 0 to 240
ct2 Operation output 1 Range DIr/Inv
ct3 Operation output 2 Range DIr/Inv
ct4 Default operation output 1 %ON 0 to 100
ct5 Default operation output 2 %ON 0 to 100
ct6 Continuous cycle time Minutes 0 to 240
Pt0 Temp. probe adjustment Degrees -20.0 to 20.0
Pt1 Decimal point Option no/yES
Pt2 Temperature units Range ºC/ºF
Pt3 Number of temp. probes Range 1 / 2
H0 Set default settings Command
H1 Keypad protection Option no/yES
H2 Communication setup Numeric 0 to 999
H3 Access code to parameters Numeric 0 to 999

Temperature parameter programming

Set Points (St1,St2) are the only parameters the user can
access without code protection.

•Press SET T. Current value of St1 appears flashing and led OUT 1
flashes.

•The value can be modified with the UP and DOWN arrows.

•Press SET again to confirm St1. Current value of St2 appears
flashing and led OUT 2 flashes.

•The value can be modified with the UP and DOWN arrows.

•Press SET to enter St2 value and exit.

Access to all code protected parameters.

•Press SET T for 8 secs. The access code value 0 is shown on the
display (unit comes with code set at 0 from factory).

• Select the correct code with the UP and DOWN arrows.

•Press SET T to enter the code. If the code is correct, the first
parameter label is shown on the display (St1).

• Move to the desired parameter with the UP and DOWN.

•Press SET T to view the value on the display.

• The value can be modified with the UP and DOWN arrows.

•Press SET to enter the value.

• Repeat until all necessary parameters are modified.

•Press SET and DOWN at the same time to quit programming or
wait one minute and the display will automatically exit programming
mode.

*The keyboard code can be reset to ZERO by turning
off the controller and turning it on again while
keeping the SET T key depressed.

Set default settings

• Access parameter H0 as explained. 0 will appear.

• Press SET T or SET H for 8 seconds. Pro will appear on the display
if the Set Point is correct and Epr will appear if it is not correct.

• Press SETT+DOWN or SETH+DOWN to exit or wait 1 minute.

Temperature control process

• Independent ON/OFF control

If rt8=ono and rt0=Ind, each output is associated to a particular Set.
If ct2=dir, output 1 will connect when TS1 >= St1+rt1 (where TS1 is
the temperature of probe 1) and will disconnect when TS1 <= St1.

Temperature

St1+rt1

St1

Output 1 ON

ct0

Time

ct0 is the minimum stop time. Once the output is disconnected, it is
not connected again until ct0 minutes later.
If ct2=Inv, output 1 will connect when TS1 <= St1-rt1 and will
disconnect when TS1 >= St1.

Temperature

St1

St1-rt1

Output 1 ON

ct0

Time

The output 2 is handled in the same manner but controlled by St2,
using rt2 as differential, ct3 as indicator of direct or reverse
connection, and ct1 as minimum stop time.

• Dependent ON/OFF control

If rt8=ono and rt0=dEP, output 1 works as in Independent ON/OFF
control, but output 2 works as follows:
If ct3=dir, output 2 will connect when TS1 >= St1+St2+rt2 (where
TS1 is the temperature of probe 1) and will disconnect when TS1
<= St1+St2.

Temperature

St1+St2+rt2

St1+St2

Output 2 ON

ct1

Time

ct1 is the minimum stop time.
If ct3=Inv, output 2 will connect when TS1 <= St1+St2-rt2 and will
disconnect when TS1 >= St1+St2.

Temperature

St1+St2

St1+St2-rt2

Output 2 ON

ct1

Time

• Cooling control

If rt8=rEF the temperature is regulated by output 1 as in ON/OFF
control, while defrosting is triggered by output 2.
Three defrosting methods are available:

1.Switch off the compressor (dt0=re)

2.Switch off the compressor and connect a heat resistor to output 2
(dt0=re)

3.Switch on the compressor and connect an electro-valve to output
2 to reverse the cycle (dt0=in)

Probe 1

Probe 1

Probe 1

Probe 1

Defrosting is performed at time periods indicated by dt3. If dt3 is
zero, no defrosting is performed periodically. Defrosting is
deactivated when TS2 (temperature of probe 2) reaches dt1 value
or when the maximum defrosting time dt2 is reached.
Defrosting can also be activated and deactivated from the keypad,
pressing the UP arrow for 8 seconds, or IR remote control.
Defrosting can not be activated if a continuous cold cycle is
activated, unit is in auxiliary adjustment mode, TS2 >=dt1 or dt2=0.
With dt4 parameter we can choose that during the defrosting and
one hour after a message -d- is displayed until the temperature
raises the initial defrosting temperature. It is also possible to show
the initial temperature during the defrosting or to show the actual
temperature all the time.

• Continuous cold cycle

A continuous cold cycle maintains the compressor (output 1) in
operation for a period of time given by ct6. These cycles are
activated from the keypad, keeping the DOWN arrow pressed for 8
seconds, and end when the time is finished or an order is given from
the keypad (pressing DOWN for 8 seconds again). The cycle will
not commence if the unit is in heat control mode or i auxiliary
adjusting mode (due to memory failure) or if defrosting is activated.

• Neutral zone control

If rt8 = NEu output 1 connects when TS1 >= St1+rt3 and
disconnects when TS1 <= St1, while output 2 connects when TS1
<= St1-rt3 and disconnects when TS1 >= St1.

Temperature

St1+rt3

St1

St1-rt3

Output 1 ON

Output 2 ON

Time

Probe 1

• Control with probe errors

If reading of probe 1 fails the output 1 works following 10 minutes
cycles, with a percentage of connection time given by Ct4. Output 2
is carried out in the same way with parameter Ct5.
If reading of probe 2 fails, the defrosting ends by time.

• Temperature alarms

If TS1 >= St1+At1, the thermostat will indicate maximum
temperature alarm for probe1 (Aht) and the alarm will remain
activated until temperature TS1 <= St1+At1-At0.
If TS1 <= St1-At2, the thermostat will activate minimum
temperature alarm for probe 1 (ALt), and it will remain activated
until temperature TS1 >= St1-At2-At0.
Program At3 to indicate the alarm check time between alarm
event and indication of an alarm event. The alarm is indicated by
a message on the display and activating the alarm output if
present (alarm can be silenced pressing SETT+DOWN keys or
CLEAR in the IR remote control).

Temperature

St1+At1

St1+At1-At0

High Alarm ON

Probe 1

Temperature

St1-At2

St1-At2+At0

Low Alarm ON

Probe 1

• Probe options

Set Pt1 to select if the decimal point is shown or not in the
display.
Set Pt2 to set temperature units (Celsius of Fahrenheit).

If the probe is not placed in the exact point to control, use a
standard thermometer to determine the offset and set it by Pt0.

Set Pt3 to select if 1 or 2 temperature probes are used.

List of humidity parameters

Description Units Range

Sh1 Humidty set point 1 %RH rh4 to rh6
Sh2 Humidty set point 2 %RH rh5 to rh7
rh0 Sh1 and Sh2 dependency Range Ind / dEP
rh1 Differencial for Sh1 %RH 0.1 to 30.0
rh2 Differencial for Sh2 %RH 0.1 to 30.0
rh3 Band differencial %RH 0.1 to 30.0
rh4 Minimum value for Sh1 %RH 0 to rh6
rh5 Minimum value for Sh2 %RH 0 to rh7
rh6 Maximum value for Sh1 %RH rh4 to 100
rh7 Maximum value for Sh2 %RH rh5 to 100
rh8 Operation mode Range ono/nEU
Ah0 Alarm differencial %RH 0.1 to 20.0
Ah1 Maximum probe alarm %RH 0.1 to 99.9
Ah2 Minimum probe alarm %RH 0.1 to 99.9
Ah3 Alarm check time hh:mm 0.0 to 18.0
ch0 Minimum stop time output 3 Minutes 0 to 240
ch1 Minimum stop time output 4 Minutes 0 to 240
ch2 Operation output 3 Range Dir/Inv
ch3 Operation output 4 Range Dir/Inv
ch4 Default operation output 3 %ON 0 to 100
ch5 Default operation output 4 %ON 0 to 100
Ph0 Hum. probe adjustment %RH -20 to 20
Ph1 Decimal point Option no/yES
Ph2 Humidity Probe type Range 1V/3V/420
Ph3 Value for 4mA %RH 0.0 to 100
Ph4 Value for 20mA %RH 0.0 to 100
H0 Set default settings Command
H1 Keypad protection Option NO/YES
H2 Communication setup Numeric 0 to 999
H3 Access code to parameters Numeric 0 to 999

Humidity parameter programming

Follow the same steps as when adjusting temperature
parameters but using the SET H key.

Humidity control process

• Independent ON/OFF control

If rh8=ono and rh0=Ind, each output is associated to a particular
Set.
If ch2=dir, output 3 will connect when HS >= Sh1+rh1 (where HS
is the humidity measured) and will disconnect when HS <= Sh1.

Humidity

Sh1+rh1

Sh1

Output 3 ON

ch0 is the minimum stop time. Once the output is disconnected, it
is not connected again until ch0 minutes later.
If ch2=Inv, output 3 will connect when HS <= Sh1-rh1 and will
disconnect when HS >= Sh1.

Humidity

Sh1

Sh1-rh1

Output 3 ON

The output 4 is handled in the same manner but controlled by
Sh2, using rh2 as differential, ch3 as indicator of direct or reverse
connection, and ch1 as minimum stop time.

ch0

Time

ch0

Time