ACCESS TO EXPANSION VALVES AND
DRAIN LINES
Mechanical
Remove product and product racks from each end
of case. Remove refrigeration and drain access
panels (labeled). The thermostatic expansion
valve (mechanical only) and drain are located
under the deck pan at end of the case.
Electronic (Optional)
The Electronic Expansion valve master and slave
cylinder(s) are located under the deck pan on the
end of the case.
ELECTRONIC EXPANSION VALVE
(Optional)
A wide variety of electronic expansion valves and
case controllers can be utilized. Please refer to
valve and controller manufacturers’ information
sheets. Sensors for electronic expansion valves
will be installed on the coil inlet, coil outlet, and
in the discharge air. (Some supermarkets require
a fourth sensor in the return air.) Case controllers
will be located in the electrical wire-way or under
the case.
THERMOSTATIC EXPANSION VALVE
ADJUSTMENT
Thermostatic expansion valves must be adjusted
to fully feed the evaporator. Before attempting
any adjustments, make sure the evaporator is
either clear or very lightly covered with frost, and
that the fixture is within 10°F of its expected
operating temperature.
MEASURE OPERATING SUPERHEAT
1. Determine the suction pressure with an accu-
rate pressure gauge at the evaporator outlet.
2. From a refrigerant pressure temperature chart,
determine the saturation temperature at the
observed suction pressure.
3. Measure the temperature of the suction gas at
the thermostatic remote bulb location.
4. Subtract the saturation temperature obtained
in step No. 2 from the temperature measured
in step No. 3. The difference is superheat.
5. Set the superheat for 5°F to 7°F (–15°C to
–14°C) average, with a swing tolerance of no
more than +/–2°F (1°C).
Island & Multi-deck Island
HUSSMANN CORPORATION • BRIDGETON, MO 63044-2483 U.S.A.
P/N 0446551_A
2-3
Electric
Drain
Refrigeration
CL
Thermostat and
Compressor Controls (S.C.)
Compressor (S.C.)
