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grease. If fan motor must be removed for service or replace-
ment, be sure to regrease fan shaft and reinstall fan guard. The
fan motor has a step in the motor shaft. For proper perfor-
mance, fan should be positioned such that it is securely seated
on this step. Tighten the bolt to 12 to 15 ft-lb (16 to 20 N-m).
IMPORTANT: Check for proper fan rotation (coun-
terclockwise viewed from above). If necessary, switch
any 2 power leads to reverse fan rotation.
Refrigerant Circuit
LEAK TESTING — Units are shipped with complete operat-
ing charge of refrigerant R-410A (see Physical Data tables
supplied in the 30RB Installation Instructions) and should be
under sufficient pressure to conduct a leak test. If there is no
pressure in the system, introduce enough nitrogen to search for
the leak. Repair the leak using good refrigeration practices.
After leaks are repaired, system must be evacuated and
dehydrated.
REFRIGERANT CHARGE — Refer to Physical Data tables
supplied in the 30RB Installation Instructions). Immediately
ahead of filter drier in each circuit is a factory-installed liquid
line service valve. Each filter drier has a
nection for charging liquid refrigerant.
Charging with Unit Off and Evacuated — Close liquid line
service valve before charging. Weigh in charge shown on unit
nameplate. Open liquid line service valve; start unit and allow
it to run several minutes fully loaded. Check for a clear sight
glass. Be sure clear condition is liquid and not vapor.
Charging with Unit Running — If charge is to be added while
unit is operating, all condenser fans and compressors must be
operating. It may be necessary to block condenser coils at low
ambient temperatures to raise condensing pressure to approxi-
mately 450 psig (3102 kPa) to turn all condenser fans on. Do
not totally block a coil to do this. Partially block all coils in
uniform pattern. Charge each circuit until sight glass shows
clear liquid, and has a liquid line temperature of 103 F (39 C).
IMPORTANT: When adjusting refrigerant charge,
circulate fluid through cooler continuously to prevent
freezing and possible damage to the cooler. Do not over-
charge, and never charge liquid into the low-pressure
side of system.
Chillers contain many safety devices
Safety Devices —
and protection logic built into electronic control. Following is a
brief summary of major safeties.
COMPRESSOR PROTECTION
Circuit Breaker — Each compressor is equipped with one
molded case circuit breaker to provide short circuit protection.
Do not bypass or increase size of a breaker to correct problems.
Determine cause for trouble and correct before resetting break-
er. Circuit breaker current rating is listed on individual circuit
breakers.
A high-pressure switch with a trip pressure of 641 psig
(4419 kPa) is mounted on the discharge line of each circuit.
Switch is wired in series with the SPM modules of all compres-
sors in the circuit. If switch opens, the SPM opens all compres-
sor contactors in the circuit and all compressors are locked off.
See the table below for high pressure switch protection.
DEVICE
CUT-OUT
High Pressure
641 ± 10 psi
Switch
(4420 ± 70 kPa)
CRANKCASE HEATERS — Each compressor has a 56-w
crankcase heater to prevent absorption of liquid refrigerant by
/
-in. Schrader con-
1
4
CUT-IN
493 ± 29 psi
(3400 ± 200 kPa)
56
oil in crankcase when compressor is not running. Heater power
source is control power transformer.
IMPORTANT: Never open any switch or disconnect
that deenergizes crankcase heaters unless unit is being
serviced or is to be shut down for a prolonged period.
After a prolonged shutdown or service, energize
crankcase heaters for 24 hours before starting unit.
Fusible plugs are located in each
Relief Devices —
circuit to protect against damage from excessive pressures.
HIGH-SIDE PROTECTION — One device is located be-
tween condenser and filter drier; a second is on filter drier.
These are both designed to relieve pressure on a tempera-
ture rise to approximately 210 F (99 C).
LOW-SIDE PROTECTION — A device is located on
suction line and is designed to relieve pressure on a tempera-
ture rise to approximately 170 F (77 C).
Some local building codes require that relieved gases be
removed. This connection will allow conformance to this
requirement.
Compressors
WARNING
Do not supply power to unit with compressor cover
removed. Failure to follow this warning can cause a fire
resulting in personal injury or death.
WARNING
Exercise extreme caution when reading compressor cur-
rents when high-voltage power is on. Correct any of the
problems described below before installing and running a
replacement compressor. Wear safety glasses and gloves
when handling refrigerants. Failure to follow this warning
can cause a fire, resulting personal injury or death.
CAUTION
Do not manually operate contactors. Serious damage to the
machine may result.
COMPRESSOR REPLACEMENT — To change out a
faulty compressor, refer to the compressor replacement proce-
dure included with the new compressor.
OIL CHARGE — All units are factory charged with polyol
ester (POE) oil to
/
sight glass. Acceptable oil level for each
7
8
compressor is
3
/
to
7
/
full in the sight glass.
4
8
CAUTION
The compressor in a Puron
(POE) oil. This oil is extremely hygroscopic, meaning it
absorbs water readily. POE oils can absorb 15 times as
much water as other oils designed for HCFC and CFC
refrigerants. Take all necessary precautions to avoid expo-
sure of the oil to the atmosphere.
When additional oil or a complete charge is required it must
meet the following specifications:
• Manufacturer . . . . . . . . . . . . . . . . .ICI Emkarate RL 32H
• Oil Type. . . . . . . . . . . . . . . . Inhibited polyol ester-based
• ISO Viscosity Grade . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Do not reuse drained oil or any oil that has been exposed to
the atmosphere.
®
system uses a polyol ester
synthetic compressor lubricant.
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