Refrigeration Repair Practice - Daikin DX17VSS B Series Service Instructions Manual

SERVICING
to check these thermistors:
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 power to all equipments.
2. disconnect the thermistor connector from the control board.
3. Connect an ohmmeter across the thermistor terminals.
the ohmmeter should read the resistance shown in the
table tHERMiStoR RESiStAnCE And tEMPERA-
tURE CHARACtERiStiCS. Replace the thermistor if
the thermistor is open, shorted, or outside the valid re-
sistance range.
Testing EEV Coil Resistance
To check the resistance of the EEV coil, first disconnect
the EEV cable from the control board. Read resistance
between the connector pins, and then make sure the resis-
tance falls in the range of 40 to 50 Ω.
Outdoor unit (HP): 1.5 - 3.0 ton
Testing Solenoid Valve Coil Resistance
to check the resistance of the solenoid valve coil, first dis-
connect the cable from the control board. Read resistance
between the connector pins, and then make sure the resis-
tance falls in the range of 1,480 to 1,820 Ω.
Outdoor unit (HP): 3.5 - 5.0 ton
Indoor unit
S-100 REFRIGERATION REPAIR PRACTICE
DANGER
Always remove the refrigerant charge in a proper
manner before applying heat to the system.
NOTICE
There is no specific "Pump down" function.
When the unit needs to be removed/relocated,
please recover all refrigerant from the system.
Use the service ports (2 locations) on the stop
valves to recover refrigerant. You may not recover
all refrigerant unless you use the 2 service ports.
When repairing the refrigeration system:
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. never open a system that is under vacuum. Air and
moisture will be drawn in.
2. Plug or cap all openings.
3. Remove all burrs and clean the brazing surfaces of the
tubing with sand cloth or paper. Brazing materials do
not flow well on oxidized or oily surfaces.
4. Clean the inside of all new tubing to remove oils and
pipe chips.
5. When brazing, sweep the tubing with dry nitrogen to
prevent the formation of oxides on the inside surfaces.
6. Complete any repair by replacing the liquid line drier in
the system, evacuate and charge.
BRAZING MATERIALS
IMPORTANT NOTE: torch heat required to braze tubes of
various sizes is proportional to the size of the tube. tubes
of smaller size require less heat to bring the tube to braz-
ing temperature before adding brazing alloy. Applying too
much heat to any tube can melt the tube. Service personnel
must use the appropriate heat level for the size of the tube
being brazed.
NOTE: the use of a heat shield when brazing is recommended
to avoid burning the serial plate or the finish on the unit. Heat
trap or wet rags should be used to protect heat sensitive
components such as stop valves, EEv and filters.
Copper to Copper Joints - Sil-fos used without flux (alloy
of 15% silver, 80% copper, and 5% phosphorous). Recom-
mended heat 1400°f.
Copper to Steel Joints - Silver Solder used without a flux
(alloy of 30% silver, 38% copper, 32% zinc). Recommend-
ed heat - 1200°f.
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