hussman VGM Refrigerant Type, Measuring the Operating Superheat, Stat Location, Refrigeration

Page 8

VGM, VGD-0505

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.

REFRIGERATION LINES

LIQUID SUCTION

3/8" O.D.

5/8" O.D.

THERMOSTATIC EXPANSION VALVE LOCATION

This device is located on the same side as the refrigera- tion stub. An ALCO expansion valve model is furnished as standard equipment, unless otherwise specified by customer.

EXPANSION VALVE ADJUSTMENT

There is one (1) valve on the right side of each coil.

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 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 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.

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, de- termine 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.

CONTROL SETTINGS

See the ÒCase SpecsÓ section of this guidebook 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 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 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).

ELECTRONIC EXPANSION VALVE (OPTIONAL)

A wide variety of electronic expansion valves and case controllers can be utilized. Please refer to EEV and controller Hussmanns information sheet. Sensors for electronic expansion valves will be installed on the coil inlet, coil outlet, and in the discharge air. (Some super- markets require a 4th sensor in the return air). Case controllers will be located in the electrical raceway or under the case

T - STAT LOCATION

T-Stats are located within the electrical raceway. Refer to diagram below.

 

 

 

 

 

 

 

 

 

 

 

 

T

 

B

 

 

 

 

B

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

WATER,

 

 

 

DRAIN

 

 

ELEC. &

 

 

 

C

 

 

 

MECHANICAL

REFRIG.

 

 

 

STUB UP AREA

L

MECHANICAL

 

 

 

19" X 19"

DRAIN

STUB UP AREA

 

 

 

 

 

 

19" X 19"

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CASE FRONT

CASE FRONT

T-STAT AND BALLAST LOCATIONS

SELF CONTAINED CASES

The only difference between a remote case and a self- contained case is the addition of a condensing unit.

SELF CONTAINED START-UP

Self contained cases are totally ready to run once power is supplied. All controls are set and units charged with refrigerant.

DEFROST SET-UP

Defrost times vary according to case model - refer to Case specification section in the back of the book for proper duration and frequency. Self contained cases have individual defrost time clocks. When power has been applied, set the time clock to the proper duration and frequency.

The time clock is located behind the front panel under the case. Turn the clock dial counterclockwise until the pointer is directed to the current time of day.

8

Image 8
Contents VGM, VGD Contents General InstructionsImportant Information Cut & Plan ViewsInstallation C a T I O NUncrating the Stand V E L I N GDo not use bolts To pull cases together Plumbing Installing Condensate DrainWaste Outlet and P Trap Humidification System Where Applicable S T R U C T I O N SHumidification Important InformationRefrigerant Type Measuring the Operating SuperheatStat Location RefrigerationCase Cleaning O C K I N GImportant Steps User InformationCleaning Glass & Mirrors CleaningPlexiglass & Acrylic Care NON Glare GlassElectrical Precautions Tips & TroubleshootingMaintenance Replacing Fluorescent LampsGlass Replacement & Right Left Adjustment Where Applicable InstructionsCase Specifications VGDElectrical Schematics Switch Dupex Outlet Single OutletLight 125-01-1023HARNESSPERBALLAST 125-01-1024HARNESSPERBALLASTElectrical Schematics Humidifier FANS1. Comair Airsweep FANS2. ComairWire OFF APC L-120-3LH Fulham LIGHT,SHELFNOSELIGHT,LEDGELIGHTLightswitch Tippette CIRCUIT#1 120-LH3 LhamfuSHELFLIGHT,NOSELIGHT,LEDGELIGHT LightsAppendix C . Field Recommendations AppendicesIs there a shortage of refrigerant? Appendix D . Recommendations to UserLimited Warranty Service Record