Frymaster H50 Series Service And Parts Manual page 39

PROBLEM
24V circuit is
suspect.
NOTE:
All voltage
measurements must be
made within 4 seconds
of the controller calling
for heat. If the burners
do not fire within 4
seconds, the ignition
modules will lock out
and the controller must
be turned off and then
back on to reset them.
Refer also to the diagrams of the 24 Volt Circuit on the following pages.
PROBABLE CAUSES
A. Failed 24V transformer.
Check: LED 3 (24V) is not lit
continuously.
B. Failed interface board.
Check 1: LED 3 (24V) is lit
continuously, but 24 VAC is not
present on the right PWR terminal
(LED 4) (and/or the left PWR
terminal (LED 2), if dual-vat).
Check 2: 24VAC is present on
V1s (or V1D and V2D, if dual
vat).
C. Open or failed drain safety switch.
Check: If 24VAC is present on
the gas valve main coil (PV ter-
minal) (on both PV terminals, if
dual-vat), check the connections
and the continuity of the drain
safety switch.
D. Failed high limit.
Check: If 24VAC is present on
the gas valve main coil (PV ter-
minal) (on both PV terminals, if
dual-vat), check the continuity of
the high limit.
E. Failed ignition module.
Check: 24VAC is not present on
V1S (or V1D and V2D, if dual
vat).
CORRECTIVE ACTION
A. If the wiring and connections be-
tween the 24V transformer and
the interface board are intact, re-
place the transformer.
B. Replace the interface board.
C. Adjust or replace the drain safety
switch as appropriate.
D. If the high limit is open, replace.
E. If the fuse in the ignition module
is not blown, replace the ignition
module.
1-33