Install Instructions

36
External Wiring
Low Voltage Connections
1. Open the display cover and unscrew both
screws to remove the front cover
2. Pull the control/display forward until it tips
downward to provide access.
3. Ensure field installed low voltage wiring is
not run parallel or next to telephone or
power cable.
4. Consult Table 4 for making low voltage
connections.
Table 4: Low Voltage Electrical
Thermostat Wiring
Isolate 120V wiring from low voltage
wiring to prevent any potential electrical
“noise”.
1. Connect room thermostat or the end switch
(isolated contact only) to the low voltage
terminal strip on the drop down control
panel, as shown in Fig. 16, page 34 and Fig.
17.
2. For proper operation install the room ther-
mostat on an inside wall away from influ-
ences of heat and cold, i.e. water pipes,
areas of draft, lighting fixtures and fire-
places.
3. Set the thermostat anticipator (if applica-
ble) as follows:
- Set for 0.1 amps when wired directly to
the CHALLENGER.
- Set to match the total electrical power
requirements of the connected devices
when wired to zone relays or other
devices. Refer to the relay manufactur-
ers’ specifications and the thermostat
instructions for additional information
on the anticipator setting.
When making low voltage connections to
the CHALLENGER, ensure no external
voltage is present in the thermostat cir-
cuits. If external voltage is present, pro-
vide an isolated contact to prevent dam-
age to the appliance control.
NOTICE
NOTICE
Fuse
Control/Display
Fig. 17: Accessing Low Voltage X4 Connections
Temperature control Connector X4 Notes
Room thermostat 7 – 8 Voltage free
Outside temperature sensor 9 – 10 -
SMART I.F.W.H 5 – 6 Voltage free
Aquastat (Optional)