Checking Compressor; S-17A Resistance Test - Daikin DP14UM Service Instructions Manual

SERVICING
Checking ECM Motor Windings
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. Disconnect the 5-pin and the 16-pin connectors from
the ECM power head.
2. Remove the 2 screws securing the ECM power head
and separate it from the motor.
3. Disconnect the 3-pin motor connector from the power
head and lay it aside.
4. Using an ohmmeter, check the motor windings for
continuity to ground (pins to motor shell). If the
ohmmeter indicates continuity to ground, the motor
is defective and must be replaced.
5. Using an ohmmeter, check the windings for continuity
(pin to pin). If no continuity is indicated, the thermal
limit (over load) device may be open. Allow motor to
cool and retest.
3-pin motor
connector
16-pin
connector
5-pin
connector
S-17 Checking Compressor
Hermetic compressor electrical terminal venting
can be dangerous. When insulating material which
supports a hermetic compressor or electrical terminal
suddenly disintegrates due to physical abuse or as a
result of an electrical short between the terminal and
the compressor housing, the terminal may be expelled,
venting the vapor and liquid contents of the compressor
housing and system.
If the compressor terminal PROTECTIVE COVER and gasket
(if required) are not properly in place and secured, there is
a remote possibility if a terminal vents, that the vaporous
and liquid discharge can be ignited, spouting flames
several feet, causing potentially severe or fatal injury to
anyone in its path.
WARNING
WARNING
This discharge can be ignited external to the compressor
if the terminal cover is not properly in place and if the
discharge impinges on a sufficient heat source.
Ignition of the discharge can also occur at the venting
terminal or inside the compressor, if there is sufficient
contaminant air present in the system and an electrical arc
occurs as the terminal vents.
Ignition cannot occur at the venting terminal without the
presence of contaminant air, and cannot occur externally
from the venting terminal without the presence of an
external ignition source.
Therefore, proper evacuation of a hermetic system is
essential at the time of manufacture and during servicing.
To reduce the possibility of external ignition, all open
flame, electrical power, and other heat sources should be
extinguished or turned off prior to servicing a system.

S-17A Resistance Test

Each compressor is equipped with an internal overload.
The line break internal overload senses both motor
amperage and winding temperature. High motor
temperature or amperage heats the disc causing it to
open, breaking the common circuit within the compressor
on single phase units.
Heat generated within the compressor shell, usually due to
recycling of the motor, high amperage or insufficient gas to
cool the motor, is slow to dissipate. Allow at least three to
four hours for it to cool and reset, then retest.
Fuse, circuit breaker, ground fault protective device, etc.
has not tripped -
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.
WARNING
17