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Refrigerant Type
The standard refrigerant will be R-404A 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.
Access Panels
All electrical and drain access panels are clearly labeled on
the deck of the produce stand. The access for condensing
units (in the self contained units) is located on the side of
the stand, at the end. Ends of stand are fitted for removal,
if condensing unit has to be taken out.
Refrigeration Lines
Liquid
3/8" O.D.
NOTE:
The standard coil is piped at
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
or 1
/
". Refer to the particular case you are hooking up.
1
8
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 RGDC technical data sheet for the appropriate
settings for your merchandiser. Maintain these parameters
to achieve near constant product temperatures. Product
temperature should be measured first thing in the
morning, after having been refrigerated overnight. For all
multiplexing, defrost should be time terminated. Defrost
times should be as follows: OFF CYCLE - One time daily
for 110 minutes. 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 and Drain Lines
Mechanical - Remove product from 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 master and
slave cylinder(s) are located within the electrical access
panel(s).
Refrigeration
Suction
5/8" O.D.
/
" (suction); however,
5
8
/
",
/
",
5
7
8
8
10
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.
Thermostatic Expansion Valve Location
An Alco balanced port expansion valve model is furnished
as standard equipment, unless otherwise specified by
customer. There is one expansion valve located on the right
side of each evaporation coil under the bottom deck pans.
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.
5. The difference is superheat.
6. Set the superheat for 5°F - 7°F.
Condenser Ventilation
Be sure to supply adequate ventilation for the condenser in
Self Contained units. Allow 150 square inches for units up
to 1 1/2 h.p., and 200 for condenser units over 2 h.p.
T-STAT Location
The T-STATS are located within the electrical raceway. The
raceway location is dependent on the style of the front panel
and whether the case is going to be pushed up against a
wall. In all cases, the T-STAT is located on the same side
of the case. If you are looking at the case from the front, it
is the right-hand side. If you are looking at the case from
the back, it is the left-hand side.
Start-up
Self Contained
On self contained cases the unit is completely charged
and tested to the proper temperature. Switch on the
compressor. Set the time clock to the proper time of day
by turning the dial in the direction of the arrow until the
pointer and current time of day align.
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