10 Troubleshooting
Troubleshooting procedure
SMGB0091 rev.2 - 11/2015
202
Phenomenon
Cause
Check item
Action
(Turn OFF the main switch)
Activation of the
float switch
(FS)
High level of
condensed water
in the drain pan
Clogging of the
drainage
Check the drain piping
Remove the clogged foreign
particles
Faulty float switch
Check the continuity when the
drain level is low
Replace the float switch if faulty
Insufficient contact or incorrect
connection
Measure the resistance using
the tester
Correct looseness and replace
the connector
Check the connections
Repair the connection
Activation of the
internal thermostat
protection of the
motor
(ITO)
Locked motor
Check the correct rotation of
the fan
Remove a possible obstacle of
the fan
Insufficient contact or incorrect
connection
Check the continuity after
the fan motor temperature
decreases to room temp
Replace the fan motor if there
is no continuity
Measure the resistance by
means of the tester
Correct looseness. Replace the
connectors
Check the connections
Repair the connections
Coil damage
Measure the coil resistance
and the insulation resistance
Replace the motor if faulty
Incorrect connection of the fan motor
or variable frequency driver (VFD)
Check the connection of the
fan motor power cables with
the connector for fan motor
power supply (CN35) and with
the fan motor terminal box.
Connect it
Check if the fan motor power
cables (U,V,W) and the
fan motor earth cable are
disconnected from the variable
frequency driver.
Repair the connections