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(©October, 2006)
CyberChiller Series Installation, Operation & Maintenance Manual
cycle, one scroll remains stationary while the other
scroll orbits around the first. As this motion occurs,
gas is drawn into the scrolls and moved in increasingly
smaller pockets toward the center. At this point, the
gas, now compressed to a high pressure, is dis-
charged from a port in the center if the fixed scroll.
During each orbit, several pockets of gas are com-
pressed simultaneously, creating smooth, nearly
continuous compression.
Due to the design of the scroll compressor, the internal
compression components always start unloaded even
if the system pressures are not balanced. In addition,
since internal compressor pressures are always
balanced at start-up, low voltage starting characteris-
tics are excellent for scroll compressors
With fewer moving parts, the
scroll compressor sets the
industry standard for reliabil-
ity among one and a half to
twelve horsepower compres-
sors. The compressor’s
simple design and proven
day-to-day performance
means less maintenance
calls for field personnel.
The scroll compressor has
demonstrated superior
durability. Its axial and radial
compliance make the scroll
compressor more tolerant to liquid refrigerant and
debris - two of the most common causes of system
failure.
The scroll compressor is quiet, but not silent. On
average, the compressor is up to five decibels quieter
than standard piston compressors. A scroll compres-
sor, however, has different sound characteristics from
reciprocating compressors. These sounds do not
affect system reliability or performance.
Upon shut-down of a normal run cycle, the compressor
will run backwards for one or two seconds as the
scrolls internal pressures are equalized. A short
reverse rotation “burp” will result. This sound is normal.
A check valve in the discharge tube of the compressor
prevents the compressor from running backwards for
more than a second or two. This normal direction
reversal of the scrolls at shut down has no effect on
compressor reliability.
Each scroll compressor comes equipped with a
crankcase heater, used to evaporate any liquid that
may have migrated to the compressor during extended
periods on non-operation (>12 hours). The crankcase
heaters are equipped with over current protection.
CAUTION
Prior to initial start-up (only when main power
has been disconnected for 12 hours or longer),
allow at least ten (10) minutes (two (2) hours is
recommended) with main power reconnected.
This will allow sufficient time for the crankcase
heaters to evaporate any liquid that may have
migrated to the compressor crankcase. When
this procedure is completed, the CyberChiller is
ready to be run.
Automatic, staged starting of the compressors is
provided to prevent an in rush of current to the
CyberChiller. High and low pressure safety switches
prevent operation of the compressor during high or low
pressure conditions.
1.2.3.8 Strainer
A “Y” strainer is included to remove any debris that
may be circulated to the chiller.
1.2.4 Safety Features
Low and high-pressure switches are provided for each
refrigeration circuit. The pressure switches are non-
adjustable encapsulated control switches. If a high
pressure switch is tripped for any reason, it must be
manually reset. The cause for tripping of the high
pressure switch must be determined. The low pressure
switches are reset automatically. These pressure
switches are installed as safety devices and will help
prevent compressor failure or other serious damage to
the system.
A flow switch is provided which will disable the refrig-
eration circuits if the coolant flow drops below a pre-
set limit.
A blocked flow bypass valve is recommended for field
installation to ensure proper return flow to the chiller at
all times.
Manual reset circuit breakers will open to de-energize
a failed component if electrical overload conditions are
encountered.
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