Trane GSSD - Manual (Page 13)

13
Pressure Switch
A high pressure switch is provided to
protect the compressor against exces-
sive refrigeration pressure. The low
pressure switch should be wired in ac-
cordance with the type of freezestat
that is used. Trane factory supplies
two low pressure switches in the re-
frigerant circuit. The electrical con-
nection is dependant upon which
freezestat (35 or 20 degree) is selected
The pressure switch is used to protect
the compressor against operation un-
der low charge or catastrophic loss of
charge situations.
The low water temperature switch is
provided to protect the water-to-re-
frigerant heat exchanger from freez-
ing. This device triggers the lock out
relay when leaving water temperatures
fall below the preset freezestat setting.
This device may be reset by cycling
power, but the system should be re-
viewed for operational error.
Important Notice
The low pressure switch should be
wired to activate at refrigerant
pressures of 35 psig when a 35
degree F freezestat is used; 7 psig
when a 20 degree F freezestat is
used. The installer should verify
that the correct freezestat and low
pressure switch are used in your
application. Misapplication can
produce a failure to the unit and
cause the warranty to be voided.
Installation- Electrical
35-DEGREE F
OR
20-DEGREE F
FREEZESTAT
WATER-OUT
WATER-IN
LIQUID LINE
SUCTION-DISCH
HEAT EXCHANGER
EXPANSION VALVE
FILTER DRIER
DESUPERHEATER
DESUPERHEATER PUMP
COMPRESSOR
LINE
DESUPERHEATER-OUT
DESUPERHEATER-IN
REVERSING VALVE
35 PSIG LOW PRESSURE
SWITCH USED FOR 35
DEGREE FREEZESTAT
7 PSIG LOW PRESSURE
SWITCH USED FOR 20
DEGREE FREEZESTAT