Reznor MAPSII Series REDA Users Manual - Manual (Page 11)

Form RZ-NA O-MAPS II, P/N 209179 R7, Page 11
The re-heat heat pump refrigerant circuit is a closed system that includes the
same components as the larger cooling circuits. The system is fully charged
with either R22 or R407C refrigerant before it leaves the factory. For charging,
see page 14.
Both the condenser coil and the compressor are located inside the coil cabinet
downstream of the cooling evaporator coil. In this location, they act to raise the
temperature (reheat) of the airstream after it has passed through the reheat
evaporator coil.
The re-heat heat pump performance can be checked in a stand-alone mode
or in conjunction with the primary refrigeration system. In general, suction line
super heat should be in the 8 to 15°F (4.5 to 8.4°C) range, and liquid line sub-
cooling should be in the 18 to 25°F (10.1 to 14°C) range.
When compared to conventional refrigeration performance, the re-heat suction
pressures will tend to be higher and discharge pressures lower.
FIGURE 5 - Operating
Head Pressure of the
Compressor in the
Re-Heat Heat Pump
Circuit
7.0 Compressor
Maintenance
and
Replacement
DANGER: Never use oxygen to pressurize a refrigeration system. Oxygen can ex-
plode on contact with oil and could result in personal injury or death. When using
high pressure gas such as nitrogen for this purpose, ALWAYS USE A PRESSURE
REGULATOR that can control the pressure down to 1 or 2 psig. Failure to use a regu-
lator will result in extremely high pressure which could exceed the burst pressure of
the compressor or other system components and result in personal injury or death.
DANGER: The refrigeration circuits are high pressure systems.
Hazards exist that could result in personal injury or death. It
is therefore required that the removal and installation of a
hermetic compressor be performed by qualified personnel
only.
Do not lift compressor by copper tubing. To prevent internal damage, compres-
sors must ALWAYS be held upright.
The following instructions include major points of consideration that will ensure
proper installation and protect you from potential personal injury. Please use
the following 13 steps as a checklist, taking each item in order before proceed-
ing to the next. If more information is required, call the Reznor Service Depart-
ment.
WARNINGS: For your safety, wear eye protection and gloves
when handling refrigerant or oil and when brazing. Have a
fire extinguisher nearby when brazing tubing.
Typical Re-Heat Heat Pump Performance
50-80°F Entering Reheat Condenser
(subtract 8 psig for liquid line pressure)
145
165
185
205
225
245
265
62 80 90
Suction Psig
Discharge Psig
50
55
60
65
70
80
°F