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6. Refrigeration
Piping
The refrigerant line outlets are located under the case.
Locate fi rst the electrical box, the outlets are then on the
same side of the case but at the opposite end. Insulate
suction lines to prevent condensation drippage.
Refrigeration Lines
Liquid
Suction
3/8" O.D.
5/8" O.D.
NOTE: The standard coil is piped at
5
/
8
" (suction); however,
the store tie-in may vary depending on the number of
coils and the draw the case has. Depending on the case
setup, the connecting point in the store may be
5
/
8
",
7
/
8
",
or 1
1
/
8
". Refer to the particular case you are hooking up.
Refrigerant lines should be sized as shown on the
refrigeration legend furnished by the store.
Install
P-TRAPS
(oil traps) at the base of all suction line
vertical risers.
Pressure drop
can rob the system of capacity. To keep the
pressure drop to a minimum, keep refrigerant line run as
short as possible, using the minimum number of elbows.
Where elbows are required, use long radius elbows only.
Control Settings
Maintain these parameters to achieve near constant product
temperatures. Product temperature should be measured
fi rst thing in the morning, after having been refrigerated
overnight. Defrost times should be as follows: OFF CYCLE
- The number of defrosts per day and the duration of the
defrost cycle may be adjusted to meet conditions present
at your location.
Access to Thermostatic Expansion
Valve (TEX) and Drain Lines
Mechanical -
Remove product from end of case. Remove
product racks. Remove refrigeration and drain access
panels (labeled). TEX valve (mechanical only) and drain
are located under each access panel at end of the case.
Electronic -
The Electronic Expansion valve master and
slave cylinder(s) are located within the electrical access
panel(s).
Electronic Expansion Valve EEV
(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.
Thermostatic Expansion Valve
Location
This device is located on the same side as the refrigeration
stub. A balanced port expansion valve model is furnished
as standard equipment, unless otherwise specifi ed 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 fi xture 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 TEX Valve.
Service Case Temperature Control
Temperature control in the upper section of the CR3 with
the Service Option is done by means of a thermostat and
suction solenoid valve. This controls both temperature
and humidity.
Thermostat (T-STAT) Location
Thermostats are located within the electrical raceway. Refer
to diagram below. There are also labels on the back of the
case indicating T-STAT location(s).
