Specifications

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The 30MPA units (condenserless) are shipped with a nitro-
gen holding charge only. After chiller assembly is completed in
the field, system must be fully charged. While the unit is run-
ning at full capacity, add refrigerant until the sight glass is clear.
R-410A is the required refrigerant.
Do not open the liquid valve until there is a charge in re-
mainder of system. A positive pressure indicates a charge in
system. With the unit operating at full load, check liquid line
sight glass to be sure the unit is fully charged (bubbles in the
sight glass indicate the unit is not fully charged).
If there is no refrigerant vapor pressure in the system, the
entire system must be leak tested. After repairing leaks, evacu-
ate the system before recharging.
Follow approved evacuation procedures when removing
refrigeration. Release remaining pressure to an approved evac-
uated cylinder.
The liquid charging method is recommended for complete
charging or when additional charge is required.
EVACUATION AND DEHYDRATION — Because the
30MP systems use polyol ester (POE) oil, which can absorb
moisture, it is important to minimize the amount of time that
the system interior is left exposed to the atmosphere. Minimiz-
ing the exposure time of the oil to the atmosphere will mini-
mize the amount of moisture that needs to be removed during
evacuation.
Once all of the piping connections are complete, leak test
the unit and then pull a deep dehydration vacuum. Connect the
vacuum pump to the high flow Schraeder valve in the suction
line and liquid line. For best results, it is recommended that a
vacuum of at least 500 microns (0.5 mm Hg) be obtained. Af-
terwards, to ensure that no moisture is present in the system,
perform a standing vacuum-rise test.
With the unit in deep vacuum (500 microns or less), isolate
the vacuum pump from the system. Observe the rate-of-rise of
the vacuum in the system. If the vacuum rises by more than
50 microns in a 30-minute time period, then continue the dehy-
dration process. Maintain a vacuum on the system until the
standing vacuum requirement is met. This will ensure a dry
system.
By following these evacuation and dehydration procedures,
the amount of moisture present in the system will be mini-
mized. It is required that liquid line filter driers be installed
between the condenser(s) and the expansion devices to capture
any foreign debris and provide additional moisture removal
capacity.
LIQUID CHARGING METHOD — Add charge to the unit
through the liquid line service valve. Never charge liquid into
the low-pressure side of the system.
1. Close liquid line ball valve (30MPA only).
2. Connect a refrigerant cylinder loosely to the high flow
Schrader valve connection on the liquid line. Purge the
charging hose and tighten the connections.
3. Open the refrigerant cylinder valve.
4. If the system has been dehydrated and is under vacuum,
break the vacuum with refrigerant gas. For R-410A, build
up system pressure to 101 psig and 32 F (697 kPa and
0° C). Invert the refrigerant cylinder so that the liquid re-
frigerant will be charged.
5. a. For complete charge of 30MPW units, follow
charging by weight procedure. When charge is
nearly full, complete the process by observing the
sight glass for clear liquid flow while the unit is
operating. The use of sight glass charging is valid
only when unit is operating at full capacity.
b. For complete charge of 30MPA units or where
refrigerant cylinder cannot be weighed, follow the
condenser manufacturer’s charging procedure or
follow charging by sight glass procedure. The use
of sight glass charging is valid only when unit is
operating at full capacity.
6. a. The 30MPA condenserless units are shipped
with a nitrogen holding charge. After installation
with the field-supplied system high side, the com-
plete system should be evacuated and charged per
the condenser manufacturer’s charging procedure
or charged until the sight glass is clear (with the
unit running at full capacity). To achieve maxi-
mum system capacity, add additional charge equal
to the difference between the condenser optimal
charge and the condenser minimum charge, which
can be obtained from the charge data provided in
the condenser installation instructions.
b. To ensure maximum performance of 30MPW
units, raise the compressor saturated discharge
temperature (SDT) to approximately 100 F
(37.8 C) by throttling the condenser water intake.
Add charge until there is approximately 9 to 12° F
(5.0 to 6.6° C) of system subcooling (SDT minus
actual temperature entering the thermostatic
expansion valve).
Operating Limitations
TEMPERATURES (See Table 20 for 30MP standard tem-
perature limits).
High Cooler Leaving Chilled Water (Fluid) Temperatures
(LCWT) — During start-up with cooler the LCWT should not
be above approximately 60 F (16 C).
Low Cooler LCWT
— For standard units with fresh water,
the LCWT must be no lower than 40 F (4.4 C). For standard
units with a proper brine solution, the LCWT must be no lower
than 32 F (0° C). If the unit is the factory-installed optional
medium temperature brine unit, the cooler LCWT can go
down to 15 F (–9.4 C).
CAUTION
Never charge liquid into low-pressure side of system. Do
not overcharge. Overcharging results in higher discharge
pressure, possible compressor damage, and higher power
consumption. During charging or removal of refrigerant, be
sure water is continuously circulating through the cooler to
prevent freezing.
CAUTION
Be careful not to overcharge the system. Overcharging
results in higher discharge pressure, possible compressor
damage, and higher power consumption.
CAUTION
Do not operate with cooler leaving chiller water (fluid)
temperature (LCWT) below 32 F (0° C) for standard units
with proper brine solution or 40 F (4.4 C) for the standard
units with fresh water, or below 15 F (–9.4 C) for units fac-
tory built for medium temperature brine or unit damage
may occur.