Specifications

30
the installation of the new compressor, tighten all hardware to
the following specifications. (See Table 21.)
Table 21 — Unit Torque Specification
30MPW Condenser and 30MP Cooler
BRAZED-PLATE COOLER AND CONDENSER HEAT
EXCHANGER REPLACEMENT — Brazed-plate heat ex-
changers cannot be repaired if they develop a leak. If a leak
(refrigerant or water) develops, the heat exchanger must be
replaced. To replace a brazed plate heat exchanger:
1. Disconnect the liquid-in and liquid-out connections at the
heat exchanger.
2. Check that the replacement heat exchanger is the same as
the original heat exchanger. For the condensers, compare
part numbers on the heat exchangers. For the coolers, in-
sulation covers the manufacturer’s part number. Make
sure the depths of the replacement and original cooler
heat exchangers are the same.
3. Recover the refrigerant from the system, and unsolder the
refrigerant-in and refrigerant-out connections.
4. Remove the four nuts holding the heat exchanger to the
brackets. Save the nuts.
5. Install the replacement heat exchanger in the unit and at-
tach to the bracket using the four nuts removed in Step 4.
For sizes 015 and 020, torque is 7-10 ft-lb. For sizes 030-
045, torque is 35 to 50 ft-lb.
6. Carefully braze the refrigerant lines to the connections on
the heat exchanger. Lines should be soldered using silver
as the soldering material with a minimum of 45% silver.
Keep the temperature below 1472 F (800 C) under nor-
mal soldering conditions (no vacuum) to prevent the cop-
per solder of the brazed plate heat exchanger from chang-
ing its structure. Failure to do so can result in internal
or external leakage at the connections which cannot be
repaired.
7. For coolers, ensure that the original size tubing is used
(
1
/
2
-in. for sizes 015 and 020 and
5
/
8
-in. for sizes 030-045)
between the TXV and the cooler. The TXV must be lo-
cated within 1 ft of the heat exchanger, with no bends be-
tween the TXV outlet and the cooler inlet.
8. Reconnect the water/brine lines.
9. Dehydrate and recharge the unit. Check for leaks.
BRAZED-PLATE COOLER AND CONDENSER HEAT
EXCHANGER CLEANING — Brazed-plate heat exchang-
ers must be cleaned chemically. A professional cleaning ser-
vice skilled in chemical cleaning should be used. Use a weak
acid (5% phosphoric acid, or if the heat exchanger is cleaned
frequently, 5% oxalic acid). Pump the cleaning solution
through the exchanger, preferably in a backflush mode. After
cleaning, rinse with large amounts of fresh water to dispose of
all the acid. Cleaning materials must be disposed of properly.
The strainers in front of the water/brine inlets of the heat
exchangers should be cleaned periodically, depending on con-
dition of the chiller water/brine.
Oil Charge
Puron refrigerant systems use a polyol ester (POE) oil. Use
only Carrier approved compressor oil. Oil should be visible in
compressor oil sight glass. An acceptable oil level is from
1
/
8
to
3
/
8
of sight glass. All compressors must be off when checking
oil level. Recommended oil level adjustment method is as
follows:
ADD OIL — Additional oil may be required in 30MPA units.
Tables 22 and 23 provide an estimate of the amount of oil re-
quired, based on the line length and the recommended pipe siz-
es. The actual circuit oil charge will depend on the application
piping. The guidelines listed are estimates and will likely need
adjusting depending on the number of traps in the application
and the pipe sizes utilized.
No attempt should be made to increase the oil level in the
sight-glass above the
3
/
4
full level. A high oil level is not sus-
tainable in the compressor and the extra oil will be pumped out
into the system causing a reduction in system efficiency and a
higher-than-normal oil circulation rate.
Add oil to suction line Schrader valve on tandem compres-
sors sets and the compressor Schrader on the trios. When oil
can be seen at the bottom of the sight glass, add oil in 5 oz in-
crements which is approximately
1
/
8
in oil level. Run all com-
pressors for 20 minutes then shut off to check oil level. Repeat
procedure until acceptable oil level is present.
NOTE: Use only Carrier approved compressor oil. Approved
sources are:
Totaline . . . . . . . . . . . . . . . . . . . . . . 3MAF POE, P903-1601
Mobil . . . . . . . . . . . . . . . . . . . . . . . . . . .EAL Arctic 32-3MA
Uniqema . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RL32-3MAF
Do not reuse oil that has been drained out, or oil that has
been exposed to atmosphere.
Check Refrigerant Feed Components
FILTER DRIER — The function of the filter drier is to main-
tain a clean, dry system. The moisture indicator (described
below) indicates any need to change the filter drier. The filter
drier is a sealed-type drier. When the drier needs to be
changed, the entire filter drier must be replaced.
MOISTURE-LIQUID INDICATOR — The indicator is located
immediately ahead of the TXV to provide an indication of the
refrigerant moisture content. It also provides a sight glass for
refrigerant liquid. Clear flow of liquid refrigerant (at full unit
loading) indicates sufficient charge in the system. Bubbles in the
sight glass (at full unit loading) indicate an undercharged system
or the presence of noncondensables. Moisture in the system,
measured in parts per million (ppm), changes the color of the
indicator as follows:
Green (safe) —Moisture is below 75 ppm
Yellow-Green (caution) — 75 to 150 ppm
Yellow (wet) — above 150 ppm
The unit must be in operation at least 12 hours before the
moisture indicator gives an accurate reading, and must be in
contact with liquid refrigerant. At the first sign of moisture in
the system, change the corresponding filter drier.
FASTENER RECOMMENDED TORQUE
Compressor Mounting
Bolts
7 to 10 ft-lb (9.5 to 13.5 N-m)
Compressor Power
Connections
24 to 28 in.-lb (2.7- to 3.2 N-m)
Compressor Ground
Terminal Connections
14 to 18 in.-lb (1.6 to 2.0 N-m)
CAUTION
The compressor in a Puron
®
refigerant (R-410A) system
uses a polyol ester (POE) oil. This is extremely hygro-
scopic, 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 precau-
tions to avoid exposure of the oil to the atmosphere. Failure
to do so could result in possible equipment damage.