EPH HDT Operating instructions
Installation and Operation Guide
Room Thermostat
HDT
3
Factory default settings
4
Specications
5
LCD Display
6
Buttons
7
Wiring
8
Mounting & installation
13
Locking the Keypad / Backlight
14
Menu Function
18
12
On / O Function & Adjusting the target temperature
15
Table of contents
16
15
Delay Start Control (On/O)
PO 1 Operating Mode
Nor (Normal Mode)
Time Proportional Integral Mode (TPI)
23
25
21
22
20
24
PO 2 Setting High and Low limits
PO 3 Hysteresis HOn and HO
PO 4 Calibration
PO 5 Frost Protection
PO 6 Setback Mode
PO 7 Resetting the Thermostat
Mains operated non-programmable Room Thermostat
Installation Instructions
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EPH Controls Ltd.
Factory default settings
Contacts: Volt Free
High and Low Temp. limitation: O
Keypad lock: O
Backlight: Auto
Setback: 0.0˚C (o)
Operating mode: Normal
4HDT
Specications
Power supply / Input: 230Vac 50-60Hz
Power consumption: Operating ≤ 1.5W
Temperature range: 5 … 35˚C
Ambient temperature: 0 … 45˚C
Ambient admissible humidity: 5-95%RH
Contact rating: 7A 230Vac
Dimensions: 85 x 85 x 36mm
Temperature sensor: NTC 100K
Backlight: White
IP rating: IP20
Pollution degree: 2
Switching dierential: Adjustable from 0.0 – 1.0°C
0.1°C increments
Automatic action: 1C
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EPH Controls Ltd.
[1]
[6]
[2]
[3][4]
[5]
[1] Shows the current / target temperature.
[2] If the keypad is locked, the lock symbol is
displayed.
[3] When the thermostat is calling for heat, the ame
symbol is displayed.
[4] When a high or low temperature limit is set, ‘LIM’
is displayed.
[5] Displayed when setback is enabled.
[6] Displayed when delay start is enabled.
LCD Display
6HDT
Buttons
Handwheel
Reset
Button
Standby Button
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EPH Controls Ltd.
Wiring
SB
ON
321LN
L
MAINS SUPPLY
N
COM
230V on Terminal 1: Thermostat works in Normal mode
0V on Terminal 1: Thermostat works in Setback mode
* If mains output is required terminals L and 2 must be electrically linked.
Terminal Connections
L Live In
N Neutral In
Terminal 1 Setback
Terminal 2 COM - Common connection
Terminal 3 ON - N/O Normally open connection
8HDT
Mounting & Installation
Caution!
Installation and connection should only be carried out by a qualied person.
Only qualied electricians or authorised service sta are permitted to open the
thermostat.
If the thermostat is used in a way not specied by the manufacturer, its safety may be
impaired.
Prior to setting the thermostat, it is necessary to complete all required settings
described in this section.
Before commencing installation, the thermostat must be rst disconnected from the
mains.
This thermostat can be mounted in the following ways:
1) Directly mounted on wall
2) To a recessed conduit box
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EPH Controls Ltd.
1) Remove the thermostat from its packaging.
2) Choose a mounting location so that the thermostat can measure
the room temperature as accurately as possible.
- Mount the thermostat 1.5 metres above the oor level.
- Prevent direct exposure to sunlight or other heating / cooling
sources.
3) To open the front housing
a) use a philips screwdriver to loosen the screw on the bottom
right of the thermostat.
b) insert and rotate a 3.5mm at screwdriver into the slot on
the bottom left.
4) Screw the backplate onto a back box or directly to the surface.
5) Wire the thermostat according to the wiring diagram on page 7.
6) Close the front housing and tighten the screw on the bottom of
the thermostat.
10 HDT
85
85
26
36
45 113
a)
b)
Mains operated non-programmable Room Thermostat
Operating Instructions
12 HDT
Press to turn the thermostat On or O.
When in the ON mode the thermostat will display the current ambient
temperature.
When in the OFF mode the thermostat will display the current ambient
temperature and the word ‘OFF’.
Rotate clockwise to increase the target temperature.
Press or wait 5 seconds. The target temperature is now saved.
Rotate anti-clockwise to decrease the target temperature.
Press or wait 5 seconds. The target temperature is now saved.
On / O Function
Adjusting the target temperature
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EPH Controls Ltd.
Locking the Keypad
To lock the thermostat, press for 10 seconds.
will appear on the screen. The buttons are now disabled.
To unlock the thermostat, press for 10 seconds.
will disappear from the screen. The buttons are now enabled.
There are three settings for selection.
‘AUt’ The backlight is on for 10 seconds when any button is pressed.
‘On’ The backlight is permanently on.
‘OFF’ The backlight is permanently o.
Rotate to change the mode between AUTO, ON and OFF.
Press to conrm selection and to return to normal operation.
Backlight AUTO
To adjust the backlight setting, press for 10 seconds.
‘AUt’ appears on the screen.
14 HDT
Menu Function
This menu allows the user to adjust additional functions.
There are three settings for selection, Normal, Delay Start or TPI mode.
The default setting is Normal.
Press and hold the and together for 5 seconds,
‘P01 & Nor’ will appear on the screen,
Press to select.
Rotate to select between
Nor (Normal mode)
dS (delay start mode)
tPi (Time proportional integral mode)
Press to conrm the mode.
PO 1 Operating Mode (Normal / Delay Start / TPI)
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EPH Controls Ltd.
Nor (Normal Mode)
When the temperature falls below the target temperature, will
appear and the thermostat will activate the demand for heat.
When the temperature rises above the target temperature, will
disappear, and the thermostat will cancel the demand for heat.
PO 1 Operating Mode (Normal / Delay Start / TPI)
22˚C
21˚C
20˚C
19˚C
18˚C
17˚C
Temp
Time Minutes
Graph (15.1): On / O Control
Target Temperature
200 40 60 80 100
16 HDT
PO 1 Operating Mode (Normal / Delay Start / TPI)
Delay Start Control (On/O)
When the delay start mode is active, ‘dS’ will appear continuously on
the screen. When in this mode the thermostat is delayed by a variable
time depending on the current temperature, target temperature and
also the fall in temperature from when the delay start has activated.
The will ash until the thermostat activates.
E.g: If the temperature is 6˚C
below the thermostat target,
the thermostat will call for
heat immediately.
If the temperature is 2˚C
below the target, the
thermostat will not call for
heat for 32 minutes.
48
42
36
30
24
18
12
6
0
0123456
Temperature below thermostat setting °C
Time delay after Delay Start activated in minutes
Graph (16.1): Delay Start Control
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EPH Controls Ltd.
Delay start can be reactivated by:
1. Lower the target below the current temperature.
2. Press to set the temperature.
3. Increase the target above the zone temperature within 6° .
4. Press to conrm.
The heating will be delayed as per the graph on page 16.
If the dierence between the actual temperature and the target is 1°C the
thermostat will delay starting for circa 40 minutes.
If the dierence between the actual temperature and the target is 3°C the
thermostat will delay starting for circa 24 minutes.
If the dierence is 6°C or more then the thermostat will be switched on
immediately.
The time delay will change if the temperature drops from the original
calculation.
When activated the thermostat will allow the heating system time to
reach the target and delay start will remain inactive until it reaches this
target.
18 HDT
PO 1 Operating Mode (Normal / Delay Start / TPI)
Time Proportional Integral Mode (TPI)
When the thermostat is in TPI mode and the temperature is rising in the
zone and falls into the Proportional Bandwidth section, TPI will start to
aect the thermostats operation. The thermostat will turn on and o as
it gains heat so that it doesn’t overshoot the target by too much. It will
also turn on if the temperature is falling so it doesn’t undershoot the
target which will leave the user with a more comfortable level of heat.
There are 2 settings that will aect the thermostats operation
1. The number of heating cycles per hour
2. The Proportional Bandwidth
CyC – Number of Heating Cycles per hour 6 Cycles
This value will decide how often the thermostat will cycle the heating
on and o when trying to achieve the target temperature. You can
select 2/3/6 or 12.
Pb -Proportional Bandwidth 2°C
Table of contents
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