PI – 03/04
Modulating Digital Thermostat
INSTALLATION MANUAL
170306-121E Rev.02
APPLICATION
PI series is a 24 VAC/VDC Modulating Digital Thermostat that provides Proportional + Integral (P+I)
control for optimum temperature control and comfort in HVAC system. It is used with the single fan speed.
Other available features include selection of Minimum / Maximum setting temperature, Digital input for
energy savings, Mode of display. The remote temperature sensor can also be provided as the optional.
PI – 03 PI – 04
Fig.1 PI – 03 & 04
Table 1 : Description of Thermostat
Model
Mounting
Operating voltage
Type of control
Power on/off switch
PI – 03
Vertical
24 VAC
Modulating 0-10V or 2-10V
No
PI – 04
Vertical
24 VAC
Modulating 0-10V or 2-10V
Yes
FEATURES
Stylish design with digital display.
Minimum temperature setting from 5 – 23 ºC (Default 11 ºC).
Maximum temperature setting from 16 – 34 ºC (Default 30 ºC).
Compatible with 10 different characteristics of modulating valve/damper.
Setting of calculating position cycle.
K
p
setting.
T
i
setting.
Temperature offset –2 to +2 ºC (Default 0 ºC).
Digital input for energy savings.
Mode of display : Room temperature, Setting temperature or % of valve/damper opening.
Remote sensor (optional) with auto detect of temperature sensor (internal or remote sensor).
Sensor error alarm.
EEPROM permanently retains user setting in case of power loss.
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SPECIFICATIONS
Table 2 : Thermostat specifications
Power supply
24 Vac nominal, 18 – 30 Vac, 50/60 Hz. or 24 Vdc nominal, 18-30 Vdc
Electrical rating
0.8 Amp maximum
Temperature setting range
5 – 34 ºC
Operating relative humidity
5 to 90 % RH, non condensing
Output
Modulating 0-10V or 2-10 V Direct/Reversing Actuating
Mounting
Directly onto wall or 2”x 4 “ vertical junction box
DIMENSIONS
Fig.2 Dimensions
OPERATION
Power on off (for Model PI - 04 only)
Use ON/OFF switch to turn on / off the system.
Temperature setting
Use △ or ▽ to change the temperature setting.
Minimum temperature set point
The system provides the facility to program the minimum setting point in a range of 5 – 23 ºC (with 2 ºC
incremental).
Maximum temperature set point
The system provides the facility to program the maximum setting point in a range of 16 – 34 ºC (with 2 ºC
incremental).
PI Control parameter
The system provides the facility to program the value of Kp and Ti.
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Temperature offset
The temperature offset can be set in a range of – 2 to + 2 ºC.
Display mode
The Display can be programmed to display room temperature, setting temperature or % of valve/damper
opening.
Temperature display in decimal number
In case of selecting program 8.0 and 9.1, Press △and ▽key simultaneously to toggle showing room
temperature in integer or decimal number. To exit this program, cut off the power.
Remote sensor (optional)
The Remote sensor can be provided as the optional. It can be the temperature module, epoxy or pipe type.
The system will automatically detect whether the internal or the Remote sensor is used.
Temperature module
Fig.3 Remote sensor
Specify the type of Remote sensor when order.
Digital input for energy savings
There is a Digital input port for energy savings provided in the system. If the input is NO contact, the system
will not do anything. If the input is NC contact, it will delay for 2 minutes and then
raise up the setting temperature for 2 ºC, and
activate the dot LED after the second digit as an alarm.
Sensor error alarm
If the temperature sensor (either internal or remote) is failed, Display will show Er in blinking.
Target error alarm
If the target of the valve/damper opening can not be reached within 2 minutes (for Feed back type only),
Display will show Ef in blinking.
Epoxy type
Pipe type
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INSTALLATION
Read these instructions thoroughly before installing
product. Failure to follow these instructions could damage
the product or cause a hazardous condition. Check the
voltage and current ratings on the product to ensure that it
is suitable for your application. Installer must be a trained,
experienced service technician. Check product for proper
operation after installation.
CAUTION
Damage to cooling system may occur.
Disconnect power from the equipment at the main
breaker/fuse block while installing the thermostat.
Mounting Location.
Mount the thermostat approximately 5 ft. (1.5 m)
above the floor in a location that is free from direct
sunlight, heat from appliances, hot or cold air from
ducts, concealed pipes and chimneys, and drafts or
dead spots behind doors or in corners. Do not mount
on exterior wall, if possible. Failure to locate
thermostat mounting as indicated will result in poor
temperature control.
NOTE: Level thermostat mounting is for appearance only
and is not required for proper thermostat operation.
Mounting Thermostat
Take out the back plate by removing the locking
screw (if any) at the bottom of the thermostat. Use
flat head screw driver to unlock the snaps. Lift and
pull it up to remove back plate.
Fig.4 Taking out back plate
The 18-22 gauge wire is recommended for wiring.
Using back plate as a guide, mark two mounting
holes on the wall. Drill two mounting holes. Place
anchors (provided) into the holes until flush with
the hole. Position back plate on the wall and
thread the wires from the heating and cooling
equipment through the wiring hole. Holding the
back plate in place on the wall, secure it to the
wall using mounting screws (provided).
Fig.5 Installing back plate
Wiring
Pull the connector from the back of thermostat by
inserting screw driver at the base of connector and
gently lift up.
Fig.6 Lifting the connector
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Fig.7 Wiring diagram
Note : Only one terminal from terminals 3&5 is
connected. It is subjected to the application.
Loosen the terminal screw, strip the wire and connect
the wire as shown in fig. 8 Firmly tighten terminal
screw when finished.
Fig.8 Connecting wire
Place the terminal back to the thermostat, make
sure it has the same orientation like in the picture
described at the back. Snap the thermostat to its
back plate.
Fig.9 Installing thermostat
Secure the thermostat by tightening the screw
provided to protect the thermostat from unwanted
access.
Fig.10 Secure the front cover
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INSTALLER SETUP
The following instructions provide information to test the cooling equipment and to change operating
parameters from the factory settings.
Enter Installer Setup
Press and hold △and ▽key simultaneously for 10 seconds to enter installer setup. The dot between the two
digit display lits showing the Installer Setup mode.
The first digit shows the Programming number.
The second digit shows the Parameter setting.
Now follow the following steps to change each of the settings. Each time you press △key, you will advance
to the next Programming number. The ▽key is used for Parameter setting.
Program 1 : Minimum temperature setting
To set the minimum temperature (5-23 ºC) allowed for the user.
Press △ key until the first digit is 1.
Press ▽key until the second digit is as required. See table below.
Second digit displays
0 1 2 3 4 5 6 7 8
9
Min. temp. setting
5 7 9
11
13
15
17
19
21
23
Note : Default setting is 11ºC.
Program 2 : Maximum temperature setting
To set the maximum temperature (16-34 ºC) allowed for the user.
Press △key until the first digit is 2.
Press ▽key until the second digit is as required. See table below.
Second digit displays
0 1 2 3 4 5 6 7 8
9
Max. temp. setting
16
18
20
22
24
26
28
30
32
34
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Note : Default setting is 30ºC.
Program 3 : Type of valve/damper
There are several types of valve/damper subject to the types actuating, feed back and direction. Program the
thermostat to match with the type of valve/damper used.
Press △key until the first digit is 3.
Press ▽key until the second digit is as required. See table below.
Second digit displays
0 1 2 3 4 5 6 7 8
9
Type of actuating
0-10V
2-10V
0-10V
2-10V
0-10V
2-10V
0-10V
2-10V
0-10V
2-10V
Type of feed back
0-10V
0-10V
2-10V
2-10V
0-10V
0-10V
2-10V
2-10V
None
None
Feed back direction
DA
DA
DA
DA
RA
RA
RA
RA
None
None
Note : DA = Direct actuating, RA = Reverse actuating
Factory setting is 3.8 (0-10 V actuating, No feed back).
Program 4 : Setting of Calculating position cycle
This program is used to select interval time of position calculation for valve control. It can be set in a range
of 30-120 seconds. The control will delay the next operation of the valve/damper until the current operation
is completed.
Press △key until the first digit is 4.
Press ▽key until the second digit is as required. See table below.
Second digit displays
0 1 2 3 4 5 6 7 8 9 Opening time (sec.)
30
40
50
60
70
80
90
100
110
120
Note : Default setting is 40 seconds..
Program 5 : Kp setting
Kp is the proportional factor that control the opening of the valve/damper. The higher Kp, the faster the room
temp. is brought to the set temp. However the fluctuation of the room temp. is also higher. Then Kp shall be
set properly.
Press △key until the first digit is 5.
Press ▽ key until the second digit is as required. See table below.
Second digit displays
0 1 2 3 4 5 6 7 8 9 Kp 1 2 4 6 8 10
12
14
16
18
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Note : Default setting is 5 (Kp = 10).
Program 6 : Ti setting
Ti is the integral factor that control the opening of the valve/damper. The higher Ti, the slower the room
temp. is brought to the set temp. However the fluctuation of the room temp. is less. Then Ti shall be set
properly.
Press △key until the first digit is 6.
Press ▽ key until the second digit is as required. See table below.
Second digit displays
0 1 2 3 4 5 6 7 8
9
Ti
40
50
60
70
80
90
100
120
160
200
Note : Default setting is 4 (Ti = 80).
Program 7 : Temperature offset
The temperature offset of the sensor’s reading can be set in a range of –2 to 2 ºC with the resolution of 0.5ºC.
Press △key until the first digit is 7.
Press ▽ key until the second digit is as required. See table below.
Second digit displays
0 1 2 3 4 5 6 7 8
Offset temp. (ºC)
-2
-1.5
-1
-0.5 0 0.5 1 1.5
2
Note : Default setting is 0 ºC.
Program 8 : Display mode
The user can set the Display to show
Room temperature or
Set temperature or
Valve/damper opening in % (by controller’s command)
Valve/damper opening in % (by actual). This can not be applied if No feed back type is used. Display
will show 00.
Press △key until the first digit is 8.
Press ▽key until the second digit is as required. See table below.
Second digit displays
0 1 2
3
Display
Room temp.
Set temp.
% valve/damper
(controller’s command)
% valve/damper
(actual)
Note : Default setting is 0 (Room temp).
Program 9 : Temperature display in decimal number
The user can set the temperature display to show
Integer number
Decimal number
Press △key until the first digit is 9.
Press ▽key until the second digit is as required. See table below.
Second digit displays
0
1
Display
Integer number
Decimal number
Note : Default setting is 0 (Integer number).
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