Transformer; Ignition Control - L.B.White Sentry ST60 Manual Del Propietário

22
Sentry Tube Heaters
4. Pull the gas valve assembly through the gas valve
door opening. See Fig. 25.
FIG. 25

Transformer

The transformer (Fig. 26) reduces the main power
supply voltage to 24 VAC. The 24 VAC is sent directly
to the ignition controller. Once the igntion controller
receives 24 VAC, an ignition cycle begins.
If the transformer is receiving main power voltage,
but 24 VAC is absent from its output terminals, the
transformer is defective. The heater will not operate.
FIG. 26
Owner's Manual • Sentry

Ignition Control

The control sends and receives voltages to operate or
verify operation of components. Refer to the following
and Fig. 27 to understand the ignition control's termi-
nal designators if doing voltage checks on the control.
L1: Line voltage to control from power supply.
IND: Line voltage from control to fan motor.
LED: Connection for control's diagnostic light wiring
harness.
MV: 24 VAC from control to gas control valve.
PS2: 24 VAC from air pressure switch back to
control
PS1: 24 VAC from control to air pressure switch.
W: 24 VAC from transformer to control. (without this
voltage the ignition control will not function)
FS: No terminal.
R: No terminal.
X: No terminal.
C/COM: Control and burner ground.
Also refer to "Operation Sequence" within this manual
as needed to understand operation of the ignition
control during a call for heat.
FIG. 27