Specification Sheet

7800 SERIESS7800A2142 4Line LCD Keyboard Display Module
25 320011007
Fault Code System Failure
Fault 57
*Purge Fan
Sw. Off*
Purge Fan Switch is off
when it should be on
(Fulton pulse only).
Inspect the Prepurge Fan Switch terminal 18 and the connec-
tions.
Make sure the switch is working properly. Reset and sequence
the relay module.
If the fault persists, replace the relay module.
Fault 58
*Combustion
pressure/
Flame*
Flame is indicated
by both the combus-
tion pressure and the
flame amplifier when
it should be off (Fulton
pulse only).
-
Faults
59–66 *Call
Service*
Unused faults. -
Fault 67 *AC
Phase*
L1 and L2 miswired/ex-
changed (EC/RM7810,
7820, 7830, 7850
only).
Check L1 and L2 for proper line phasing.
Fault 68
*Pre-Ignition
ILK*
Pre-Ignition Interlock
fault.
Check wiring; correct any errors.
Inspect the Pre-Ignition Interlock switches and make sure
they work
properly.
Check fuel valve operation. Valve must close within five
seconds.
Reset and sequence the relay module.
During STANDBY or PREPURGE, measure the voltage be-
tween terminal 17 and G (ground). Supply voltage should be
present. If not, the Pre-ignition Interlock switches are defec-
tive and need replacing.
If the fault persists, replace the relay module.
Fault 69–70
*Call Service*
Unused faults. -
Fault 71
*Dynamic
LFS*
Low Fire Switch closed,
High Fire Switch must
be open (EC/RM7850
only).
Check firing rate position switches (usually in Modutrol®
Motor) for proper operation.
Check wiring, correct any errors.
Reset and sequence the relay module.
If the fault persists, replace the relay module
Fault 71
*Limits Com-
plete*
Limit input (terminal 7)
is off when it should be
on (RM7888 only).
Check limits to make sure they are satisfied after resetting.
Check electrical connections to terminal 7 of wiring subbase.
Reset relay module.
If the fault persists, replace the relay module.
Fault 72
*Dynamic
HFS*
High Fire Switch closed;
Low Fire Switch must
be open (EC/RM7850
only).
Check firing rate position switches (usually in Modutrol®
Motor) for proper operation.
Check wiring, correct any errors.
Reset and sequence the relay module.
If the fault persists, replace the relay module.
Fault 72
*Spec.
Func.2*
Special Function 2 In-
put (terminal 17) is off
when it should be on.
Check operation of Special Function 2 of PLC.
Check electrical connection to terminal 17 of wiring subbase
and confirm presence of supply power when Special Function
2 is activated.
Reset relay module.
If the fault persists, replace the relay module.
Fault 73
*Spec.
Func.3*
Special Function 3 In-
put (terminal 19) is off
when it should be on.
Check operation of Special Function 3 of PLC.
Check electrical connection to terminal 19 of wiring subbase
and confirm presence of supply power when Special Function
3 is activated.
Reset relay module.
If the fault persists, replace the relay module
Fault 74
*Unused*
Unused fault. -