Liberty Pumps SX-Series - Manual (Page 11)

Fuses
Check the continuity of the fuse. With power OFF,
pull the fuse out of the fuse block. With the ohm-
meter on the R X 1 scale, measure resistance. A
reading of infi nity indicates a blown fuse and must
be replaced. Replace fuse with same type, voltage
and amp rating.
Indicator Lights
If defective, replace all indicator pilot lights with
same type.
Magnetic Contactor
Contacts - Check the contacts for severely burnt
or welded contacts. The contactor arm should
move freely.
Coil - Measure the coil by disconnecting one of
the coil leads. Measure the coil resistance by set-
ting the ohmmeter on the R X 1 scale. A defective
coil will read zero or infi nity, indicating a short or
opened coil respectively. Replace defective con-
tactor with same type.
NOTE: Readings may vary depending on accuracy
of the measuring device.
Motor Protective Switch
Test by inserting a paper clip or other small device
into the test hole and push to the left. The relay
should trip.
Alarm Horn
Moving the alarm test/normal/silence switch to the
test position or activating the alarm fl oat should
turn on the alarm horn. If the horn does not sound
replace with horn of same type.
Alarm Light
Moving the alarm test/normal/silence switch to the
test position or activating the alarm fl oat should
turn on the alarm light. If the light does not activate,
replace with bulb of same type.
Float Controls
Check the fl oats during their entire range of opera-
tion. Clean, adjust, or replace fl oats.
Checking the fl oat resistance - The fl oat resis-
tance can be measured to determine if the fl oat
is operating correctly or is defective. Use the fol-
lowing procedure to measure the fl oat resistance:
1. Isolate the fl oat by disconnecting one or both
of the fl oat leads from the fl oat terminals.
2. Place one ohmmeter lead on one of the fl oat
wires, and the other ohmmeter lead on the
other fl oat wire.
3. Place the ohmmeter dial to read ohms and
place on the R X 1 scale. With the fl oat in the
“off” position, the scale should read infi nity
(high resistance). Replace the fl oat if you do
not get this reading. With the fl oat in the ON
position, the scale should read nearly zero
(very low resistance). Replace the fl oat if you
do not get this reading.
NOTE: Readings may vary depending on the
length of wire and accuracy of the measuring
device.
Troubleshooting
- 5 -
7227000B