S-17A Resistance Test; S-17B Ground Test; Testing Thermistor, Eev Coil And Solenoid Valve Coil Resistance - Daikin DX17VSS B Series Service Instructions Manual

SERVICING

S-17A RESISTANCE TEST

inverter on the outdoor unit control board takes the position
signal from the UvW line connected with the compressor.
When the system detects the malfunction on the compres-
sor, check the insulation resistance in accordance with the
following procedure.
HIGH VOLTAGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be present. Failure to do so may
cause property damage, personal injury
or death.
1. Remove the leads from the compressor terminals.
See warnings S-17 before removing compressor
terminal cover.
2. Check the wiring connection of UvW on compressor
terminal. (the terminal indicated label located on the
top of compressor.)
3. Check the insulation resistance of compressor between
the compressor terminal and unpainted refrigerant pip-
ing.
Unpainted
Refrigerant
Piping
OHMMETER
TESTING COMPRESSOR WINDINGS
NOTE: the compressor has terminal on the top.
4. if the insulation resistance of compressor is different
from infinity, replace the compressor.
24

S-17B GROUND TEST

if fuse, circuit breaker, etc., has tripped, this is a strong in-
dication that an electrical problem exists and must be found
and corrected. the circuit protective device rating must be
checked, and its maximum rating should coincide with that
marked on the equipment nameplate.
With the terminal protective cover in place, it is acceptable
to replace the fuse or reset the circuit breaker onE tiME
onLy to see if it was just a nuisance opening. if it opens
again, do not continue to reset.
Disconnect all power to unit, making sure that all power
legs are open.
1. do not remove protective terminal cover. disconnect
the three leads going to the compressor terminals at
the nearest point to the compressor.
2. identify the leads and using an ohmmeter on the R
x 10,000 scale or the highest resistance scale on
your ohmmeter check the resistance between each
of the three leads separately to ground (such as an
unpainted tube on the compressor).
3. if a ground is indicated, then carefully remove the
compressor terminal protective cover and inspect for
loose leads or insulation breaks in the lead wires.
4. if no visual problems indicated, carefully remove the
leads at the compressor terminals.
5. Carefully retest for ground, directly between compressor
terminals and ground.
6. if ground is indicated, replace the compressor. the
Compressor
resistance reading should be infinity. if there is any
Terminal
reading on meter, there is some continuity to ground
and compressor should be considered defective.
WARNING
Damage can occur to the glass embedded terminals if
the leads are not properly removed. This can result in
terminal and hot oil discharging.
S-26 TESTING THERMISTOR, EEV COIL AND
SOLENOID VALVE COIL RESISTANCE
outdoor units, dv*fEC air handler and CAPE(A)/CHPE
cased coil models are factory equipped with:
• (Ta) an outdoor air thermistor
• (Tm) an outdoor coil thermistor
• (TI) an outdoor liquid thermistor
• (Td) an outdoor discharge thermistor
• (Tb) an outdoor coil defrost thermistor
• (Ts) an outdoor suction thermistor
• (Tgi) an indoor gas thermistor
• (Tli) an indoor liquid thermistor