Carrier 50ZHK, Installation Instructions Manual, Page: 19 / 22

50ZHK: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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Metering Devices
Refrigerant cooling metering device is a piston located upstream of the
indoor coil distributor assembly. Refrigerant heating mode metering
device is a piston located upstream of the outdoor coil distributor
assembly.
High Flow Valves
High flow valves are located on the compressor hot gas and suction
tubes. Large black plastic caps distinguish these valves with O-rings
located inside the caps. Ensure the plastic caps are in place and tight or
the possibility of refrigerant leakage could occur. To replace valve core
body without removing charge, service tool p/n SCFT20A is required.
High Pressure Switch
The high-pressure switch is located in the discharge line and protects
against excessive condenser coil pressure. It opens at 650 psig (4482
kPA). High pressure may be caused by a dirty condenser coil, failed fan
motor, or condenser air recirculation.
To check switch:
1. Turn off all power to unit.
2. Disconnect leads on switch.
3. Apply ohmmeter leads across switch. You should have continuity
on a good switch.
Loss of Charge Switch
The loss of charge switch is located in the liquid line and will protect the
compressor against a loss of charge condition. It opens at 20 psig (138
kPa). If switch is open check system pressures. If pressures are normal,
check continuity and wiring of switch. Repair or replace as required.
Puron (R-410A) Compressor
The compressor used in this product is specifically designed to operate
with Puron (R-410A) refrigerant and cannot be interchanged.
The compressor is an electrical (as well as mechanical) device. Exercise
extreme caution when working near compressors. Power should be shut
off, if possible, for most troubleshooting techniques. Refrigerants
present additional safety hazards.
Compressors vary in type by unit size. See Table 8 below for compressor
type by size.
All compressors in these units have internal overload protection. This
protection will interrupt motor current under fault conditions such as
running current overload. The Copeland Scroll compressors also have
internal pressure relief that will relieve from the high side to the low side
if the differential is between 550 and 625 psig.
Refrigerant
This system uses Puron (R-410A) refrigerant which has higher operating
pressures than R-22 and other refrigerants. No other refrigerant may be
used in this system. Gauge set, hoses, and recovery system must be
designed to handle Puron (R-410A). If you are unsure, consult the
equipment manufacturer. Failure to use Puron (R-410A) compatible
servicing equipment or replacement components may result in property
damage or injury.
Compressor Oil
Use only manufacturer suggested compressor oil, see Table 8 for correct
oil.
NOTE: Alternate manufacturer approved compressor oil for Copeland
Scroll compressor: Uniqema RL32-3MAF, Copeland Ultra 32 CC,
Mobil Arctic EAL22 CC, ICI Emkarate RL22 or ICI Emkarate 32CF.
This oil is extremely hygroscopic, meaning it absorbs water readily.
POE/PVE oils can absorb 15 times as much water as other oils designed
for HCFC and CFC refrigerants. Take all necessary precautions to avoid
exposure of the oil to the atmosphere.
Servicing Systems on Roofs with Synthetic
Materials
POE/PVE (polyolester) compressor lubricants are known to cause long
term damage to some synthetic roofing materials. Exposure, even if
immediately cleaned up, may cause embrittlement (leading to cracking)
to occur in one year or more. When performing any service that may risk
exposure of compressor oil to the roof, take appropriate precautions to
protect roofing. Procedures which risk oil leakage include, but are not
limited to, compressor replacement, repairing refrigerant leaks, replacing
refrigerant components such as filter drier, pressure switch, metering
device, coil, accumulator, or reversing valve.
Synthetic Roof Precautionary Procedure
1. Cover extended roof working area with an impermeable
polyethylene (plastic) drip cloth or tarp. Cover an approximate 10 x
10 ft (3 x 3 m) area.
2. Cover area in front of the unit service panel with a terry cloth shop
towel to absorb lubricant spills, prevent run-offs, and protect drop
cloth from tears caused by tools or components.
3. Place terry cloth shop towel inside unit immediately under
component(s) to be serviced and prevent lubricant run-offs through
the louvered openings in the unit base.
4. Perform required service.
5. Remove and dispose of any oil contaminated material per local
codes.
Liquid Line Filter Drier
The filter drier is specifically designed to operate with Puron (R-410A).
Use only factory-authorized components. Filter drier must be replaced
whenever the refrigerant system is opened. When removing a filter drier,
use a tubing cutter to cut the drier from the system. Do not unsweat a
filter drier from the system. Heat from unsweating will release moisture
and contaminants from drier into system.
WARNING
!
EXPLOSION HAZARD
Failure to follow this warning could result in personal injury or death
and/or property damage.
Wear safety glasses and gloves when handling refrigerants. Keep
torches and other ignition sources away from refrigerants and oils.
Table 8 – Compressor Type
UNIT
COMPRESSOR
TYPE
MANUFACTURER SUGGESTED
OIL TYPE
024 Copeland Scroll 3MAF Polyolester Oil (POE)
030 Copeland Scroll 3MAF Polyolester Oil (POE)
036 LG Scroll RB32G Polyolester Oil (POE)
042 LG Scroll RB32G Polyolester Oil (POE)
048 Copeland Scroll 3MAF Polyolester Oil (POE)
060 Copeland Scroll 3MAF Polyolester Oil (POE)
CAUTION
!
EXPLOSION, ENVIRONMENTAL SAFETY HAZARD
Failure to follow this warning could result in personal injury, death or
equipment damage.
This system uses Puron (R-410A) refrigerant which has higher
operating pressures than R-22 and other refrigerants. No other
refrigerant may be used in this system. Gauge set, hoses, and recovery
system must be designed to handle Puron (R-410A). If you are unsure,
consult the equipment manufacturer.