International Comfort Products NASA001SC Installation Manual
INSTALLATION INSTRUCTIONS
PTC Compressor Start Assist
NASA001SC
These instructions must be read and understood completely before attempting installation.
Safety Considerations:
Installing and servicing of air conditioning equipment can be hazardous due to system pressure and electrical
components. Only trained personnel should install or service air conditioning equipment.
Untrained personnel can perform basic maintenance functions such as cleaning coils or cleaning and replacing filters.
All other operations should be performed by trained service personnel. When working on air conditioning equipment
observe precautions in the literature and on tags and labels attached to the unit.
Follow all safety codes. Wear safety glasses and work gloves. Use a quenching cloth for brazing operations. Have a
fire extinguisher available.
Safety Labeling and Signal Words
DANGER, WARNING, CAUTION, and
NOTE
The signal words DANGER, WARNING, CAUTION, and NOTE are used to identify levels of haz-
ard seriousness. The signal word DANGER is only
used on product labels to signify an immediate hazard. The signal words WARNING, CAUTION, and
NOTE will be used on product labels and throughout this manual and other manuals that may apply
to the product.
DANGER − Immediate hazards which will result in
severe personal injury or death.
WARNING − Hazards or unsafe practices which
could result in severe personal injury or death.
CAUTION − Hazards or unsafe practices which
may result in minor personal injury or product or
property damage.
NOTE − Used to highlight suggestions which will
result in enhanced installation, reliability, or operation.
Signal Words in Manuals
The signal word WARNING is used throughout this
manual in the following manner:
WARNING
!
The signal word CAUTION is used throughout this
manual in the following manner:
!
Signal Words on Product Labeling
Signal words are used in combination with colors
and/or pictures on product labels.
WARNING
CAUTION
!
ELECTRICAL SHOCK HAZARD
Failure to turn off electric power could result in
personal injury or death.
Before installing or servicing system, turn off
main power to the system. There may be more than
one disconnect switch, including accessory
heater(s).
WARNING
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in unit
damage
PTC temperature can exceed 250° F during unit
operation. Make sure no wiring comes in contact
with the device. Do not touch the device during
unit operation.
CAUTION
482 01 5160 00 January 2006
INSTALLATION INSTRUCTIONS PTC Compressor Start Assist
INTRODUCTION
This instruction covers the installation of PTC
Compressor Start Assist kit Part No. NASA001SC for air
conditioners and heat pumps.
DESCRIPTION AND USAGE
The Positive Temperature Coefficient (PTC) thermistor
causes the compressor “run” capacitor to be bypassed for
a brief period of time at start up, creating extra starting
torque in the compressor motor. Use with 208−volt,
230−volt, or 208/230−volt, 60−hertz, single−phase units.
Included in the kit are:
Mounting Bracket 1
Wiring Label 1
Wires 3
Three−terminal PTC Thermistor 1
Installation Instructions 1
INSTALLATION
1. Mount clamp in electrical control box with at least
½ inch clearance of all surfaces including electrical
terminals and wires that could conduct electricity.
Route and secure all wires away from thermistor
body.
2. Install short jumper wire to connect 2 end terminals
of PTC thermistor. Use other 2 wires to connect
center terminal and either 1 of end terminals to run
capacitor. (Refer to Figure 1.)
3. Push PTC thermistor into its holding clamp.
4. Attach the wiring label supplied with the kit to the
unit control box cover near the unit wiring label.
5. Replace all panels on unit.
The PTC Compressor Start Assist is designed to boost
compressor starting torque.
Refrigerant flow−control devices, capillaries, or
bleed−type thermostatic expansion valves (TXV) can be
used as metering devices in systems utilizing this PTC
thermistor.
NOTE: This PTC thermistor, in most instances, will not
provide adequate starting torque for non−bleed systems
or for systems equipped with a start capacitor and relay.
If this kit is used to replace an existing PTC device, simply
remove the defective PTC device and install the new one
in the existing bracket.
Figure 1 PTC (Start Thermistor) Wiring
TO CONTACTOR
CONTACTS
RUN CAPACITOR
*
TO COMPRESSOR
TERMINALS
TROUBLESHOOTING
The PTC thermistor is a fail−safe device. If the
component becomes defective it will fail to open (breaking
the circuit).
The PTC thermistor is a resistor with an inherent
self−heating characteristic. The temperature of the PTC
device increases very rapidly at start−up and its
increased resistance reaches a level that takes it out of
the circuit within approximately 2 seconds.
If a unit having a PTC device fails to start the compressor,
remove PTC device from unit and take to a cool place.
Wait 10 minutes for device to cool, then check for an open
circuit. The resistance between either end terminal and
the middle terminal with the jumper installed across both
end terminals should be its normal resistance of 12 to 25
ohms.
PTC
START THERMISTOR
JUMPER
If the PTC device is in working condition, measure the line
voltage. The line voltage must be within voltage operating
range indicated on unit rating. Also check that system
pressures are equalized. Some compressors may
experience rough handling in transit and may fail to start
due to a locked condition. Should a compressor fail to
start for this reason, “bump” it with an appropriately sized
start capacitor. After this initial “bump” and an hour run−in,
the compressor should restart with the PTC thermistor.
2 482 01 5160 00
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