rev. 1209
9
electronic expansion Valve (optional)
A wide variety of electronic expansion valves and case
controllers can be utilized. Please refer to EEV and
controller manufacturers 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. The
front Self Service Evaporator has an EPR valve installed to
maintain a constant discharge temperature. It is located in
the front at the right side of the case under the fan plenum
near the TX valve.
thermostatic expansion Valve location
This device is located on the same side as the refrigeration
stub. A Sporlan balanced port expansion valve model
is furnished as standard equipment, unless otherwise
specified by customer.
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.
Measuring the operating superheat
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.
The difference is superheat.
5. Set the superheat for 5°F - 7°F.
evaporator pressure regulator
An Evaporator Pressure Regulator is installed in the front
of the self service section to maintain a constant discharge
temperature. It is located at the front right side of the case,
under the fan plenum near the TX Valve.
service case temperature control
Temperature control in the upper section of the R3 with
the Service Option is done by means of a thermostat and
suction solenoid valve. This controls both temperature
and humidity.
t-stat location
T-STATS are located within the electrical raceway. Refer
to diagram below.
refrigeration (cont'd)
refrigeration data
note:
this data is based on store temperature and humidity
that does not exceed 75f and 55% r.h.
discharge air (f) 28
evaporator (f)
20
note:
not recommended to control temp by regulating coil
temp allow t-stat to cycle and control temp.
Btu/hr/total*
parallel
750
conventional
863
*For all refrigeration equipment other than Hussmann use
conventional Btu values.
defrost data
frequency hrs
6
offtiMe
temp term °f
54
failsafe Minutes
40
electric or Gas not recommended
physical data
Merchandiser Drip Pipe (in.)
1 ½*
Merchandiser Liquid Line (in.)
3/8*
Merchandiser Suction Line (in.)
5/8*
Estimated Charge (lb)***
4ft
1.2
5ft
1.5
6ft
1.8
*Dependent on case length and refrigerant type.
*** This is an average for all refrigerants types. Actual
refrigerant charge may vary by approximately half a
pound.
Glycol requirements
GpM
psi
n/a
n/a
n/a
n/a
n/a
n/a
