Operation – Trane GHND-SVX01A-EN User Manual
Page 28
28
GHND-SVX01A-EN • High Efficiency Propeller Fan Gas Unit Heater
POWER VENTED PROPELLER UNITS INTERMITTENT (SPARK) PILOT IGNITION
EXPLANATION OF CONTROLS:
1.
The unit heater is equipped with a power venter system consisting of a power
venter motor and blower, pressure switch, and sealed flue collector in place of the
conventional draft diverter.
Note: IMPORTANT! The addition of external draft hoods or power ventors is not
permitted. Addition of such devices may cause severe unit malfunction or
failure!
2.
The power venter motor is energized by the room thermostat on a call for heat. The
pressure switch measures the flow through the vent system and energizes the
indirect spark ignition system when the flow is correct.
Note: IMPORTANT! The pressure switch MUST NOT be bypassed. The unit MUST NOT
be fired unless the power ventor is operating.
3.
The indirect spark ignition system consists of an ignition control module, a dual
combination valve, and a spark-ignited pilot burner. When the pressure switch
closes, the pilot valves opens and a spark is generated to light the pilot burner.
When flame sensing circuit senses that the pilot flame is established, the main gas
valve is opened to supply gas to the main burners. When the thermostat is satisfied,
the vent system is deenergized and both valves are closed to stop all flow of gas to
the unit.
4.
The limit switch interrupts the flow of electric current to the main gas valve in case
the heater becomes overheated.
5.
The fan switch delays the operation of the fan until the heater is warmed, then
keeps the fan running after the gas has been turned off until the useful heat has
been removed. The startup fan delay must not exceed 90 seconds from a cold start.
6.
The wall thermostat (supplied optionally) is a temperature sensitive switch which
operates the vent system and the ignition system to control the temperature of the
space being heated. It must be mounted on a vibration free, vertical surface away
from air currents, in accordance with the instructions furnished with the thermostat
(also refer to Electrical Section).
Operation