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OPERATION
AND TROUBLESHOOTING 50E47-843
M
V
2
T
R
G
N
D
T
H
M
V
1
L
2
F
P
L
1
H
S
1
THERMOSTAT OR
CONTROLLER
ALTERNATE
LIMIT
L1
(HOT)
L2
LIMIT
CONTROLLER
FLAME
PROBE
RED
ADAPTER
BLUE
HOT
SURFACE
IGNITER
MV
MV
GAS
VALVE
BURNER
GROUND
H
S
2
TRANSFORMER
JUMPER
(clip)
YELLOW FLASHING INDICATOR: IMPROPER POLARITY LOCKOUT
RED SOLID INDICATOR LIGHT: INTERNAL FAULT OR REVERSED CONNECTIONS AT GAS VALVE
YELLOW FLASHING INDICATOR (IMPROPER POLARITY LOCKOUT): Yellow indicator will flash if the polarity is not correct
as diagrammed above on both the primary and secondary of the system transformer.
To check the polarity on the primary of the transformer it can be tested at the module. The L1 terminal on the module should
be 120 volts (Hot) and should measure 120 volts to GND.
To check the secondary of the transformer, module terminal L1 should measure approximately 95 volts to TH. If the reading
is approximately 120 to 150 volts the secondary is not phased correctly. To correct this condition, reverse the secondary wires
on the system transformer. Note: TR on this module is tied to GND. Some systems may have more than one ground. When
you reverse the 24 volt secondary be sure that only the TR and GND leads are grounded.
RED SOLID INDICATOR LIGHT (INTERNAL FAULT OR REVERSED CONNECTIONS AT GAS VALVE): A solid red indicator
light means internal module fault or reversed connections at the gas valve. Before replacing the module, reverse
low voltage connections to gas valve.
At installation, this module has a self-test and requires all system components (Transformer, Ignitor, Gas Valve and Flame
Sensor) to be attached and turned on for it to operate. Gas valves with an Electric “On/Off” switch must be turned “ON”. A
lockout condition on this control during self-test will not damage equipment or the control.
* NOTE: Ground this terminal if model being replaced does not have 120V neutral
*
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