Herz H7990 Series User manual

H7990 series Touch Pad fan coil unit thermostats are designed to control the room
temperature in air-conditioning fan coil unit system or dust pipe channel system. H7990
series thermostats with microprocessor and big LCD display. It shows the following items:
working status(cool, heat or ventilation), fan speed, room temperature, set-point
temperature etc. Keys include on/off ( ),mode ( ),fan speed ( ) and temperature
adjustment (  ).
BASIC FEATURES
Room temperature setting
Manual or auto 3-speed changeover
Defrost (low temperature protection)
Clock, Timer ( -T, Option )
Clock ,7 days programmable ( -T74, Option )
Blue back light ( -L, Option )
Keypad Lock (Option )
Auto Restart ( Option )
STATUS DISPLAY
Working Status: Cooling , Heating or Ventilation
Fan Speeds: low , Mid ,High or Auto
FCU valve status
Room temperature display
Temperature setting display
Clock ,week display
SPECIFICATIONS
Sensing element: NTC
Control Accuracy:
 1℃
Set-point range: 5℃to 35℃
Display range: 0～55℃
Operation environment: 0～45℃
Operating Humidity: 5～90%RH (non-condensing)
Key: Touch screen key+ soft touch key
Power Consumption : 1W
Power supply: AC 85～260V, 50/60Hz
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Display Accuracy: 0.5℃
Wirings: Accepting 2 × 1.5 mm2or 1 x 2.5mm2wires
Switch current rating: Resistive: 2 A, Inductive: 1 A
Housing: PC + ABS Flame Retardant
Dimensions: 90 × 90 × 14.5mm ( W × H × D )
Hole pitch: 60 mm ( Standard )
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Protection Class: IP30
H7990 Series Touch Pad Thermostat
Data sheet for H7990, Issue 0916
HERZ Armaturen Gws.m.b.H
Richard-Strauss-Strasse 22,1230 Vienna, Austria.
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OPERATION
On/Off : Press “ ” to turn on, press “ ” again to turn off thermostat and its output.
Setting temperature: press “” to reduce temperature, press “” to raise temperature (0.5℃changed each
press)
Mode Selection: Press “ ” to change system working in cooling “ ”, heating “ ” or ventilation “ ”mode.(The
Fan speed Selection (not for H7990 Y/YE): Press “ ”to select (Hi), (Med), (Low), AUTO(Auto).
In mode “AUTO”(Auto)”, the fan-speed changed automatically. Auto LOW-speed When the differential temperature
between room-temperature and setting-temperature exceed 1℃, Auto MED-speed When exceed 2℃, Auto HI-speed
When exceed 3℃.
Control Damper (H7990 Y/YE): The damper will be open when room temperature is higher than set-point in
cooling; room temperature is lower than set-point in heating, Otherwise the damper will be closed.
Control Motorized Valve under 2-pipe configuration (not for H7990 Y/YE): If the differential temperature between room
temperature and set-point exceed 1℃, FCU valve will be open; if room temperature and set-point are equal,H7990 DA/
DAE/DA2/DA2E will close the FCU valve with the fan still running, H7990 DB/DBE/DB2/DB2E will close both of valve and
Fan.
Control FCU Valve under 4-pipe configuration (H7990 FCV2/FCV2E): In cooling, when the room temperature
is higher than set-point, the cooling Valve will be opened. Otherwise it will be closed. Heating valve is always closed.
In heating, When the room temperature is lower than set-point, the heating valve will be opened. Otherwise it will be
closed. Cooling valve is always closed.
CLOCK CALIBRATION ( -T, -T74 )
Press “M” with four seconds till to display “hh:mm” and “hh” flash, press “” or “” to adjust hour, press “M”,
“mm” flash, press “” or “” to adjust minute; Press “M”, “week” flash, press “” or “” to adjust Mon to Sun.
TIMER FUNCTION SETTING ( -T )
Timer on/off function: Turn on or Turn off the thermostat according to customers setting
Timer on: Press “M”, till to display “ON” and “hh” all flash, press “” or “” to adjust hour. Press “M”, “mm” flash,
press “” or “” to adjust minute.
Timer off: Press “M”, till to display “OFF” and “hh” which all flash, press “” or “” to adjust hour. Press “M”,
“mm” flash, press “” or “” to adjust minute.
Canceling timer on: Press “M”, till to display “ON” and “hh” which all flash, press “” or “” to adjust hour to
“--:--”. Press “M”, “mm” flash, press “” or “” to adjust minute to “--:--”.
Canceling timer off: Press “M”, till to display “OFF” and “hh” which all flash, press “” or “” to adjust hour to
“--:--”. Press “M”, “mm” flash, press “” or “” to adjust minute to “--:--”.
7 DAYS PROGRAMMING (-T74)
Divide each day of one week (7 days) into four events, set the temperature respectively to satisfy different room
temperature requirements in different time.
Power On: Press “ ” and “ ” at same time for 3 seconds till displaying “SET”, ”1” and “MON”, to set the 7days
4periods programs based on the following table. When “hh” of “hh:mm”is flashing, ”▲”or ”▼” button to set the hours of
programming time; Press “ ”, “mm” of “hh:mm” is flashing, “▲” or ”▼” button to set the minutes of programming time;
HERZ Armaturen Gws.m.b.H
Richard-Strauss-Strasse 22,1230 Vienna, Austria.
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Press“ ”, the programmable temperature is flashing, “▲” or”▼” to set the programmable temperature. Press“ ”, repeat
the above steps to set up the 2～4 periods of Monday.
Week
Period NO. 1
Period NO. 2
Period NO. 3
Period NO. 4
Starting Time/
Temperature
Starting Time/
Temperature
Starting Time/
Temperature
Starting Time/
Temperature
Mon
7:00 25℃
8:00 25℃
18:00 25℃
21:00 25℃
Tue
7:00 25℃
8:00 25℃
18:00 25℃
21:00 25℃
Wed
7:00 25℃
8:00 25℃
18:00 25℃
21:00 25℃
Thu
7:00 25℃
8:00 25℃
18:00 25℃
21:00 25℃
Fri
7:00 25℃
8:00 25℃
18:00 25℃
21:00 25℃
Sat
7:00 25℃
8:00 25℃
18:00 25℃
21:00 25℃
Sun
7:00 25℃
8:00 25℃
18:00 25℃
21:00 25℃
Repeat the above steps to set for TUE, WED, THU, FRI, SAT, SUN.
Keypad Lock Function
Keypad Lock: its keypad would be automatically locked in 30 seconds in case that no one uses the thermostat,
so as to prohibit other persons from operating the thermostat.
Keypad Unlock：Press“ ”for 5 seconds to unlock（In case that no one uses the thermostat, its keypad would be
automatically locked in 30 seconds）.
Low Temperature Protection Function
Turn off: When the room temperature is lower than 5℃, the thermostat would automatically turn on the fan and
valve with “ ” showing, When the room temperature reaches to 7℃, the thermostat will automatically close the output.
Low Temperature Protection Setting
Turn off: press” ” and hold for 3 seconds, it will display “OF” or “ON”, press “▲” or “▼”button to adjust the
parameter. “OF” indicates low temperature protection invalid, “ON” indicates low temperature protection function valid.
The default is “OF”.
Temperature Adjustment
In case that the user wants the displayed temperature on the thermostat higher or lower than the real
temperature(±5℃), the following operations could be taken：
Turn off: press “▲” and “▼” at the same time for 3 seconds, it will display “XX ℃”（not displaying the working
model）, press “▲”or “▼” to adjust the temperature value, it will be automatically confirmed after 6 seconds.
Alarm
if the sensor has failure, the thermostat will close the fan and valve, displaying “E1” or “E2”.
E1：Sensor in short circuit alarm
E2：Sensor in open circuit alarm
It displays“HI” when the temperature is higher than 55℃, displaying “LO” when the temperature is lower than 0°C
HERZ Armaturen Gws.m.b.H
Richard-Strauss-Strasse 22,1230 Vienna, Austria.
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Wiring Diagrams
MOUNTING
Note: Be sure to connect all the wires as per the wiring diagrams and keep it away from water,
mud and other material so as to prevent the unit being spoiled!
1. Open the main control
panel: put the screwdriver
(3.5mm) into the block
4mm along the bevel.
Prize up, open the clips.
2. Take off the wires.
3. As per wiring diagram,
connect it with terminals,
fixed by the screwdriver.
4. Put the connected
thermostat onto the back
panel in the wall, then fix
it with the two screws in
the packing box.
5. Put the cover with 30
degree angle, then fix the
up two clips;
6. Push the places of the
two down clips, fix the
cover, and finish the
installation.
Med
Low
H7990 25
L
N
Val
Fan
Valve
AC85～260V 50/60Hz
N L
Hi
Low
H7990 27
L
N
VO
Med
Fan
Valve
VC
AC85～260V 50/60Hz
N L
Hi
Val2
Low
H7990 26
L
Cooling
N
Med
Fan
Val1
4-pipe
L
Cooling
N
Mid
mI
Low
Fan
Val1
Val2
Heating
AC85～260V 50/60Hz
N L
Hi
l
2
Heating
AC85～260V 50/60Hz
N L
Hi
Close
Open
H7990 28
N
L
Fan
AC85～260V 50/60Hz
N L
HERZ Armaturen Gws.m.b.H
Richard-Strauss-Strasse 22,1230 Vienna, Austria.
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