Accumulators - Emerson Copeland Scroll ZH04K1P Manual

Figure 5: Suction tube connecting areas

The copper-coated steel tubes on scroll compressors can be brazed in approximately the
same manner as any copper tube.

Recommended brazing materials: any silfos material is recommended, preferably with a
minimum of 5% silver. However, 0% silver is acceptable.

Be sure tube fitting inner diameter and tube outer diameter are clean prior to assembly.

Using a double-tipped torch, apply heat in area 1.

As the tube approaches brazing temperature, move the torch flame to area 2.

Heat area 2 until braze temperature is attained, moving the torch up and down and rotating
around the tube as necessary to heat the tube evenly. Add braze material to the joint while
moving the torch around the joint to flow braze material around the circumference.

After the braze material flows around the joint, move the torch to heat area 3. This will draw
the braze material down into the joint. The time spent heating area 3 should be minimal.

As with any brazed joint, overheating may be detrimental to the final result.
To disconnect:

Heat joint areas 2 and 3 slowly and uniformly until the braze material softens and the tube
can be pulled out of the fitting.
To reconnect:

Recommended brazing materials: Silfos with minimum 5% silver or silver braze used on
other compressors. Due to the different thermal properties of steel and copper, brazing
procedures may have to be changed from those commonly used.
NOTE: Since the discharge stub contains a check valve, care must be taken not to
overheat it to prevent brazing material from flowing into it.
NOTE: Since the injection tubing design of the ZHI*K1P compressors includes some
O-rings, a wet rag or any other suitable heat protection device must be used when
brazing the injection line to the compressor.
3.3

Accumulators

CAUTION
Inadequate lubrication! Bearing and moving parts destruction! Minimise
liquid refrigerant returning to the compressor. Too much refrigerant dilutes
the oil. Liquid refrigerant can wash the oil off the bearings and moving parts
leading to overheating and bearing or compressor failure.
Due to Copeland Scroll compressors inherent ability to handle liquid refrigerant in flooded start
and defrost cycle operation, an accumulator is not required for durability in most systems.
However, large volumes of liquid refrigerant repeatedly flooding back to the compressor during
normal off cycles, or excessive liquid refrigerant flooding back during defrost or varying loads,
can dilute the oil, no matter what the system charge is. As a result, bearings and moving parts
will be inadequately lubricated and wear may occur.
To determine if the accumulator can be removed, dedicated tests must be carried out to ensure
that excessive liquid does not flood back to the compressor during defrost or varying loads. The
defrost test must be done at an outdoor ambient temperature of around 0°C in a high humidity
environment. Liquid floodback must be monitored during reversing valve operation, especially
when coming out of defrost. Excessive floodback occurs when the sump temperature drops
below the safe operation line shown in Figure 6.
If an accumulator has to be used,
models ZH04K1P to ZH19K1P and ZHI05K1P to
ZHI46K1P, depending on compressor size and compressor floodback results.
protective screen no finer than 30 x 30 mesh (0.6 mm openings) is required to protect this small
10
Copeland Scroll compressors have copper-plated
steel suction, injection and discharge tubes. These
tubes are far more robust and less prone to leaks
than copper tubes. Due to the different thermal
properties of steel and copper, brazing procedures
may have to be changed from those commonly used.
Refer to Figure 5 and procedure below for the
brazing of the suction and discharge lines to a Scroll
compressor.
the oil-return orifice should be from 1 to 1.4 mm in diameter for
ZHI23K1P, and 2.0 mm for models ZHI27K1I to
A large-area
C6.2.26/1013-1116/E