TM 9-4940-558-14&P
5.4.1.5 In order to check FS-1 flame switch and TD-1 time delay relay
for proper operation follow this procedure:
Connect water/power to unit.
Turn main switch OFF.
2.
Disconnect (white) lead from FS-1 connected to terminal
3.
number 5 (ref. JP7201-A) - Insulate end of this wire -
Connect volt meter (240 Vac) across terminal 1 and 5.
4.
Turn ON main power switch.
Turn pump switch ON.
When burner switch is turned on 220 volts should read
5.
for 45 seconds (between terminal 1 and 5).
After 45 seconds, voltage should drop to O.
6.
If initial voltage is O (and assuming PS-2, TC-1 and S-3
7.
are functional) time delay (TD-1) is defective.
8.
If after 45 seconds voltage (1 and 5) DOES NOT drop to O
the time delay relay is defective.
With main power switch OFF, meter in OHMS MODE, check the
9.
resistance between the wire removed in step 3 and terminal
4. This should check open (infinite resistance) if shorted,
flame sensor must be replaced.
If during normal operation the burner operates for 45 seconds
10.
and shuts off, the flame switch is not closing and it must
be replaced.
No spark can be caused by:
5.4.2
Faulty high voltage wire - replace.
a.
Damp transformer (arcking at transformer outlet) - dry
b.
transformer and wire.
Defective transformer - replace.
Improper burner spark gap - gap 3/32 to 1/8 inch.
d.
"Bridged" burner gap (most probable cause). Remove burner (ref.6.13),
e.
clean electrode.
f.
Cracked porcelain insulation on electrode - replace.
Improper voltage - connect to correct voltage.
g.
TROUBLE SHOOTING - AIR SYSTEM
5.5
Rain cap closed.
a.
5.5.1 Poor Combustion
Air baffle on blower inlet improperly
b.
positioned.
c.
Jack Shaft drive belt/pulleys loose.
Fail loose.
d.
Improper motor pulley installed for
e.
frequency of power supply.
f.
Insufficient oxygen in air supply.
Missing air baffle in center of heating
g.
coil.
h.
Blockage in air chamber (chassis cavity).
Hole in air chamber.
i.
Improper venting (restriction) of
j.
exhaust gas.
k.
Burner throat misshapen.
l.
Burner whirler blades bent.
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