Air
Water
Safety
Symptom
Head
Suction Compressor Super Subcooling Temp (loops) Temp
Lock
Pressure Pressure Amp Draw
Heat
Differential Differential
Out
Charge
Undercharge System
Low
Low
Low
High
Low
Low
Low
Low Pressure
(Possible Leak)
Overcharge System
High
High
High
Normal
High
Normal
High
Pressure
Low Air Flow Heating
High
High
High
Low
High
Low
High Pressure
Low Air Flow Cooling
Low
Low
Low
High
High
Low
Low Temp
Low Water Flow Heating
Low
Low
High
Low
High
Low Temp
Low Water Flow Cooling
High
High
High
High
Low
Low
High
High Pressure
High Air Flow Heating
Low
Low
Low
Low
High
Low
Low
Low Temp
High Air Flow Cooling
Low
High
Normal
High
Low
Low
Normal
High Pressure
High Water Flow Heating
Normal
Low
Normal
High
Normal
Normal
Low
High Pressure
High Water Flow Cooling
Low
Low
Low
Low
High
Normal
Low
Low Temp
TXV Restricted
High
Low
High
High
Low
Low
IM 742 / Page 25
High
Normal
Low
Normal
Normal
Low
Troubleshooting Refrigeration Circuit
Troubleshooting
The in and outs of Enfinity
™
R-410A
Refrigerant 410A is a non-ozone depleting blend of two
refrigerants HFC-125 and HFC-32 in a fifty percent mix-
ture . Refrigerant 410A exhibits higher operating pressure
and refrigeration capacity than R-22 . R-410A refrigerant
is intended for use in new air conditioning application that
has traditionally been serviced by HCFC-22 or R-22 . Due
to higher capacity and pressure of R-410A, it is not recom-
mended as a retrofit to existing R-22 systems .
Although R-410A is non-flammable at ambient tem-
perature and atmosphere pressure, it can become com-
bustible under pressure when mixed with air. (NOTE:
R-410A should not be mixed with air under pressure for
leak testing.
Pressure mixtures of dry nitrogen and R-410A
can be used for leak testing .)
Lubrication
R410A should be used only with polyolester (POE) oil . The
HFC refrigerant components in R-410A will not be compat-
ible with mineral oil or alkylbenzene lubricants . R-410A sys-
tems will be charged with the OEM recommended lubricant,
ready for use with R-410A .
Charging
Due to the zeotropic nature of R-410A, it should be charged
as a liquid . In situations where vapor is normally charged
into a system, a valve should be installed in the charging
line to flash the liquid to vapor while charging .
Warning
It is very important to make certain that the recycle or recov-
ery equipment used is designed for R-410A . The pressure
of R-410A refrigerant is approximately 60 percent greater
than that of R-22 . Pressure gauges require a range up to
800 PSIG high side and 250 PSIG low side . Recovery cyl-
inders require a 400 PSIG rating – do not put R-410A in a
300 PSIG rated cylinder .
(NOTE: because a water source heat pump operates under
a wide range of water and air temperatures, the values
printed below are to be taken as suggested pressure and
temperatures .) All McQuay water source heat pumps are
designed for commercial use . The units are designed for
the cooling mode of operation and fail safe to cooling .
The revising valve is energized for the heating mode of
operation .
Superheat
Head Pressure
Water Delta T
8 to 14 degrees
335-355 PSIG
10° to 12°
All information above is based on ISO standard 13256-1
and are tested at these conditions .
Normal
Low
Low
Normal
Low
Normal