Tjernlund GPAK-JT,1T 8504034 Rev 11/97 - Manual (Page 10)

ALTERNATIVE THERMOSTAT WIRING FOR SINGLE ZONE INSTALLATIONS
SEQUENCE OF OPERATION ON PAGE 7 CHANGES AS FOLLOWS WHEN WIRING WITH SINGLE ZONE THERMOSTAT:
Adjust the furnace thermostat to call for heat. The Power Venter should start. After a slight delay, the furnace burner should fire.
The delay is caused by the Power Venter fan proving switch. The delay will be no more than 4 seconds, if you are unable to detect a
slight delay, contact Tjernlund Products, Inc. at 1-800-255-4208 for assistance. When the fan proving switch closes, the furnace com-
bustion relay is energized. Normal combustion sequence for the furnace begins: Induced draft furnace blower starts, its proving
switch makes energizing ignition control and/or gas valve. DO NOT OPERATE THE FURNACE WITHOUT THE FAN PROVING
SWITCH WIRED INTO THE 24V FURNACE CIRCUIT!
NOTE: When Power Venter is interlocked with thermostat wire all zones, circulators and limits as would normally be done if
venting into a chimney.
If you are unable to wire the GPAK as outlined in these instructions, call Tjernlund’s Customer Service Department toll free at
1-800-255-4208 for fast assistance.
OPERATION CIRCUIT CHECK
1. After all appliance and GPAK wiring is complete, establish 115V power to the appliance and Power Venter with the appliance
thermostat/aquastat not calling for heat. The Power Venter may operate when power is first established, wait until the Power
Venter shuts off before continuing.
2. Adjust the appliance thermostat/aquastat to call for heat. At this point, the Power Venter should start. After a slight delay, the
appliance burner should fire. The delay is caused by the Power Venter Fan Proving Switch. The delay will be no more than 4
seconds, if you are unable to detect a slight delay, contact Tjernlund Products, Inc. at 1-800-255-4208 for assistance.
A) Wired to gas valve: When the Power Venter Fan Proving Switch closes, the circuit to the gas valve is completed.
B) Wired to thermostat: When the Power Venter Fan Proving Switch closes, the furnace combustion relay is energized,
Normal combustion sequence for the furnace begins: Induced draft furnace blower starts, its proving
switch makes energizing ignition control and/or gas valve.
DO NOT OPERATE THE APPLIANCE WITHOUT THE FAN PROVING SWITCH WIRED INTO THE 24V APPLIANCE CIRCUIT!
3. Adjust the appliance thermostat/aquastat so that no heat is required. At this point the Power Venter and appliance should shut off.
NOTE: With the GPAK-JT or GPAK-1T, the Power Venter will continue to run for a non-adjustable time of approximately 45
seconds after the appliance burner shuts off.
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WIRING GPAK-JT/GPAK-1T WITH THERMOSTAT