Jandy Lite2 Installation And Operation Manual page 34

Page 32
10.4.3.1 Transformer
Attach the red lead of the voltmeter to the
terminal on the secondary side of transformer with a
yellow wire attached to it (common). This is test point
1 on Figure 23. Touch the free lead of the voltmeter to
the terminal on the secondary side of transformer with
a red wire attached to it (24V tap), test point 2. The
voltmeter should read between 20-28 Volts. If the
voltage does not fall within the limits mentioned above,
replace the transformer.
10.4.3.2 Fuse
Leave the red voltmeter lead in place at test point
1. Touch the black lead of the voltmeter to test point 3,
which is where the red wire from the transformer
attaches to the fusible link. The meter should read 20-
28 Volts. If there is no voltage, the fuse has failed.
Inspect the rest of the wiring, especially the safety
circuit, to be sure that there is no "short" such as
contact of a terminal with the heater chassis or
another terminal which may have caused the fuse to
fail. Correct any such condition and replace the fuse.
Use only a 2 amp, 1 1/4" long x 1/4" diameter, quick
acting, glass tube type fuse.
10.4.3.3 Fusible Link
Leave the red voltmeter lead in place at test point
1. Touch the black lead of the meter to the terminal of
the fusible link where the white wire from the fireman
switch terminal is connected (test point 4).
If no voltage is detected at test point 4, the
fusible link has failed. This indicates higher than
normal temperatures in the component compartment
(vestibule). Normal component compartment tempera-
o
ture is well below 300 F. The fusible link is designed to
fail at temperatures above 305°F. Excessive tempera-
ture might be due to a blocked flue or heat exchanger.
Clean the heat exchanger and clear the flue and vent
of any restrictions. Sometimes the fusible link fails due
to flame roll-out. Flame roll-out may be caused by
delayed ignition or downdrafting in windy areas.
Thoroughly investigate the causes for flame roll-out
and correct the problem when replacing the fusible
link.
10.4.3.4 Fireman Switch and External
Interlocks
Check the voltage going to the external device.
Touch the black lead of the meter to the fireman
switch terminal strip where the white wire from the
fusible link is connected (test point 5). The meter
should read at least between 20 and 28 VAC. If the
voltage is not within this range, there may be a bad
connection or wire between the fusible link and the
terminal strip. The wire may need to be replaced. If
voltage of 20 or more is detected at test point 5, move
the black lead of the meter to the fireman switch
terminal strip connection where the white wire from
the high limit is connected (test point 6). The meter
should read within the range of 20-28 VAC. If there is
no voltage, the time clock switch or other external
interlock may be mis-adjusted, mis-connected or
defective. Correct this external problem.
10.4.4 Limit Switches
Since the limit switches are not easily accessible,
you can check the voltage going into the component
after the limit switches in the circuit. If voltage is
detected there, then the limit switches are closed and
are operational.
Check the voltage going to the water pressure
switch. Leave the red voltmeter lead in place at test
point 1. Touch the black lead of the meter to the
terminal of the water pressure switch where the white
wire is connected (test point 11).
If the voltage is less than 20 VAC, there may be
a bad connection, a partial short or a faulty sensor. If
there is no voltage, one of the limit switches is open.
This is normally due to excessive water temperature,
which should be thoroughly investigated before
replacement of limit switches. Excessive water
temperature may be caused by low water flow. Water
flow deficiency may be due to obvious problems such
as a defective pump or blocked water filter. Alterna-
tively, excessive water temperature may be due to
over-firing, or to a problem with the water piping or the
heater's internal bypass control. Over-firing might be a
result of an incorrect gas orifice or supply of propane
gas to a heater intended for natural gas.
If there are no such fundamental problems,
identify which of the switches is open. Limit switch
access is through the limit switch cover on the inlet/
outlet header. Remove the cover and retainer bracket
from the high limit switches and remove the limit
switches from the wells. Move the black lead of the
meter to the terminal on the 150°F limit switch (test
point 7) that is connected to the fireman switch
terminal block. Less than 20 V at this point means that
the wire between the terminal block and the limit
switch has a poor or broken connection or a partial
short. Replace the wire assembly. If at least 20 V is
detected at test point 7, then move the black lead of
the meter to the other terminal of the 150°F limit
switch (test point 8). Low or no voltage here means
that the limit is open and must be replaced.
If 20 V or more is detected at test point 8, move
the black lead of the meter to the terminal on the
135°F limit switch (test point 9) that is connected to
the 150°F limit switch. Less than 20 V at this point
means that the wire between the two limit switches
has a poor or broken connection or a partial short.
Replace the wire assembly. If at least 20 V is detected
at test point 9, then move the black lead of the meter
to the other terminal of the 135°F limit switch (test