Table of Contents
Advertisement
Electronic Expansion Valve (Optional)
A wide variety of electronic expansion valves and case
controllers can be utilized. Please refer to EEV and
controller Hussmann's information sheet. Sensors for
electronic expansion valves will be installed on the coil inlet,
coil outlet, and in the discharge air. (Some supermarkets
require a 4th sensor in the return air). Case controllers will
be located in the electrical raceway or under the case.
Expansion Valve Adjustment
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.
After case has been brought to running temperature
verify screws along glass clamp aluminum
extrusion are tight.
Refrigeration (Cont'd)
Measuring the Operating Superheat
Thermostat Location
Thermostats are located in the electrical section; behind
the rear panel, on the right-hand side of the case (facing
the back of the case).
14
1. Determine the suction pressure with an accurate
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.
5. The difference is superheat.
6. Set the superheat for 5°F - 7°F.
Advertisement
Table of Contents
