82
Table 15 - Acceptable Air-Cooled
Refrigeration Circuit Values
Air-Cooled Cond./Air-Source Heat Pump
Sub-Cooling**
8-15°F / 2-4°F (HP)*
Sub-Cooling with
Hot Gas Reheat**
8-15°F / 2-6°F (HP)*
Superheat***
8-15°F
*In cooling mode operation
**Sub-cooling must be increased by 2°F per
20 feet of vertical liquid line rise for R-410A
***Superheat will increase with long
suction line runs.
Table 16 - Acceptable Water-Cooled
Refrigeration Circuit Values
Water-Cooled Condenser
Sub-Cooling
4-8°F
Sub-Cooling with
Hot Gas Reheat
8-15°F
Superheat
8-15°F
Adjusting
Sub-Cooling
and
Superheat
Temperatures
The system is overcharged if the sub-cooling
temperature is too high and the evaporator is
fully loaded (low loads on the evaporator
result in increased sub-cooling) and the
evaporator
superheat
is
within
the
temperature range as shown in the table
above (high superheat results in increased
sub-cooling).
Correct an overcharged system by reducing
the amount of refrigerant in the system to
lower the sub-cooling.
The system is undercharged if the superheat
is too high and the sub-cooling is too low
Correct an undercharged system by adding
refrigerant to the system to reduce superheat
and raise sub-cooling.
If the sub-cooling is correct and the
superheat is too high, the TXV may need
adjustment to correct the superheat. Before
adjusting the TXV, verity the sensing bulb is
in the correct position according to Figure
20 and follows the guidelines below.
1. The suction line is clean where the
sensing bulb is attached.
2. The entire length of the sensing bulb is in
contact with the suction line.
3. The sensing bulb should be placed several
inched downstream of the equalizer line.
4. The sensing bulb is fully insulated.
5. If the sensing bulb is installed on a
vertical portion of the suction line, the
sensing bulb should be placed upstream of a
suction line trap.
DO NOT OVERCHARGE!
Refrigerant overcharging leads to
excess refrigerant in the condenser
coils resulting in elevated compressor
discharge pressure.
CAUTION
Thermal expansion valve must be
adjust to approximately 8-15°F of
suction superheat. Failure to have
sufficient superheat will damage the
compressor and void the warranty.
CAUTION
Summary of Contents for M2 Series
Page 2: ......
Page 5: ...5 Split System Piping Diagrams 98 M2 Series Startup Form 115 Maintenance Log 121 ...
Page 35: ...35 Table 1 Electric and Gas Heating Capacities ...
Page 38: ...38 Figure 5 M2 Series Unit Four Point Lifting ...
Page 39: ...39 Figure 6 M2 Series Unit Eight Point Lifting ...
Page 58: ...58 Figure 32 Supply Fan Banding ...
Page 95: ...95 Figure 52 Filter Layout Viewed from the Upstream Side of the Cooling Coil ...
Page 98: ...98 Split System Piping Diagrams Figure 53 A C Split System Piping Suction Down ...
Page 99: ...99 Figure 54 A C Split System Piping Suction Up ...
Page 100: ...100 Figure 55 A C with LAC Split System Piping Suction Up ...
Page 101: ...101 Figure 56 A C with Modulating Hot Gas Reheat Split System Piping Suction Down ...
Page 102: ...102 Figure 57 A C with Modulating Hot Gas Reheat Split System Piping Suction Up ...
Page 103: ...103 Figure 58 A C with Hot Gas Bypass Split System Piping Suction Down ...
Page 104: ...104 Figure 59 A C with Hot Gas Bypass Split System Piping Suction Up ...
Page 107: ...107 Figure 62 Heat Pump Split System Piping Suction Down ...
Page 108: ...108 Figure 63 Heat Pump Split System Piping Suction Up ...
Page 109: ...109 Figure 64 Heat Pump with Modulating Hot Gas Reheat Split System Piping Suction Down ...
Page 110: ...110 Figure 65 Heat Pump with Modulating Hot Gas Reheat Split System Piping Suction Up ...
Page 111: ...111 Figure 66 Heat Pump with Hot Gas Bypass Split System Piping Suction Down ...
Page 112: ...112 Figure 67 Heat Pump with Hot Gas Bypass Split System Piping Suction Up ...