Refrigeration System - GE GEH50DEED Technical Service Manual

Hybrid water heater

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Owner's manual (72 pages)

Owner's manual & installation instructions (25 pages)

Owner's manual & installation instructions (72 pages)

Table Of Contents

Table of Contents

Electronic Expansion Valve (EEV)

This valve replaces the capillary tube typically used

in refrigeration appliances. The EEV meters the flow

of liquid refrigerant entering the evaporator at a rate

that matches the amount of refrigerant being boiled

off in the evaporator (gas). The valve maintains the

proper superheat between the evaporator inlet and

evaporator outlet.

Superheat is the temperature of a gas above the

boiling point for that liquid. if a refrigerant liquid

boils at a temperature of 40°F in a cooling coil, and

then the refrigerant gas increases in temperature,

superheat has been added. if this refrigerant

changed from a liquid to a gas or vapor at 40°F, and

then the refrigerant vapor increased in temperature

to 50°F, it has been superheated by 10°F.

At temperatures of 95°F or lower, the EEV maintains

the proper superheat of approximately 10°F (T3b-

T3a). Although the EEV is designed to maintain

a superheat of approximately 10°F (T3b–T3a), a

range of 5°F to 15°F is considered normal when

temperatures are between 45°F and 95°F.

To prevent the compressor from stalling at

temperatures of 95°F or greater, the superheat value

changes. The control takes the T5 temperature

minus 95 and adds 10 to calculate superheat,

superheat = (T5-95)+10. The EEV will then maintain

a superheat within 1 degree of the target

temperature.

Example: Ambient temperature is 110.

Superheat is (110-95)+10 = 25. Target temperature

is 25+/- 1.

The T3a (inlet) and T3b (outlet) sensors monitor the

evaporator temperature. The board then energizes a

stepper motor which rotates a magnet-needle valve

assembly and by means of a screw structure linear

motion, opening and closing to regulate refrigerant

flow.