Rev.0105
5
Refrigeration
REFRIGERANT TYPE
The standard refrigerant will be R-22 unless otherwise
specified on the customer order. Check the serial plate
on the case for information.
PIPING
The refrigerant line outlets are located under the case.
Locate first 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
See the “Case Specs” section of this guidebook for the
appropriate settings for your merchandiser. Maintain
these parameters to achieve near constant product
temperatures. Product temperature should be mea-
sured first thing in the morning, after having been
refrigerated overnight. For all multiplexing, defrost
should be time terminated. Defrost times should as
directed in the Case Specifications section of this guide.
The number of defrosts per day should never change.
The duration of the defrost cycle may be adjusted to
meet conditions present at your location.
ACCESS TO TX VALVES & DRAIN LINES
MECHANICAL
- Remove product from left end of case.
Remove product racks. Remove refrigeration and drain
access panels (labeled). TX valve (mechanical only) and
drain are located under each access panel at end of the
case.
ELECTRONIC
- The Electronic Expansion valve control-
ler is located within the electrical access panel(s)
(Remote models only).
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 race-
way or under the case
THERMOSTATIC EXPANSION VALVE LOCATION
This device is located on the same side as the refrigera-
tion stub. An Alco 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.
3. The difference is superheat.
5. Set the superheat for 5
°
F - 7
°
F.
T-STAT LOCATION
T-Stats are located within the electrical raceway. Refer
to diagram below.
Optional
Light
RCD - Remote
Shown with Options
Scale = 3/4"
T Stat
RCD - SC
Shown with Refrigerated Rear Storage
Scale = 3/4"
T Stat
COIL
