Refrigeration
REFRIGERANT TYPE
The standard refrigerant will be
PIPING
The refrigerant line outlets are located under the fixture at the left hand end when viewed from the back. Insulate the suction lines to prevent condensation leakage.
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
5/8", 7/8", or 11/8". 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
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 tempera- tures.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 loca- tion.
ACCESS TO TX VALVES & DRAIN LINES
tronic 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
AnAlco balanced port expansion valve model is furnished as standard equipment, unless otherwise specified by cus- tomer.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 evapo- rator. 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.
FAN SPEED CONTROL
Located in the electrical raceway on the lower right end is a fan speed control.This control is set at the factory for maximum. To adjust, turn the knob clockwise to obtain approximately 50 FPM air speed. This may vary due to store ambient conditions, especially the relative humidity. With low humidity, slow the fan.With high humidity con- ditions, set the control for maximum. Each case has its own control and allows independant settings in case line- ups.
NOTE: Slow air picks up more humidity from coil and ice.
MECHANICAL - Remove product from the case. Remove product racks (if applicable).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).
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 elec-
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 condensr units over 2 h.p.
6