SECTION 15: W
IRING
65 of 91
15.3 Ladder Diagram
15.4 External Wiring (Unitary Heaters Only)
Heaters can be controlled
u
sing several methods.
Normally thermostats are
u
sed to control the
heaters, b
u
t they can also be controlled by an energy
management system.
ill
u
strates the connection for heaters controlled by a
line voltage thermostat. For single or m
u
ltiple heaters
on one lo
w
voltage thermostat,
L1
L2
120V
24V
FAN
GAS VALVE
PRESSURE
SWITCH
SENSE
GAP
IGNITION
MODULE
TRANSFORMER
