CeilAir DX Series Manuel de l'opérateur télécharger pdf (Page 36)

(Mar, 2012)

CeilAiR OHS Series Installation, Operation & Maintenance Manual

ir Technology Systems, Inc.

2.9.8.1 Snap Acting Hot Gas Bypass

The snap acting hot gas bypass system provides for

some modulated capacity control and freeze protec-

tion. The hot gas bypass system includes a discharge

bypass valve that allows some hot gas from the com-

pressor discharge line to pass into the evaporator coil

to maintain a preset suction pressure. The compres-

sor cycles on demand from the controller.

The snap acting hot gas bypass system also provides

freeze protection for the evaporator coil by limiting the

minimum refrigerant pressure, preventing the surface

temperature of the evaporator coil from dropping

below 32°F.

The normal control setting is 50-55 psig (suction

pressure) read from the suction (low) side of the

compressor as it operates in full hot gas bypass

operation. The valve is factory set and no adjustment

should be necessary. If adjustment is required, block

one half of the coil and remove adjustment cap from

end of valve. Using a 5/16 inch Allen wrench, turn

clockwise to increase pressure or counterclockwise

to lower pressure.

2.9.8.2 Full Floating Hot Gas Bypass

A full ﬂ oating hot gas bypass system is provided for

capacity control and freeze protection. The hot gas

bypass system may include a quench solenoid valve,

a quench solenoid coil, a quench expansion thermal

valve, a hot gas (discharge) solenoid valve, a hot

gas (discharge) solenoid coil, and a hot gas bypass

valve. To ensure a constant running compressor, the

hot gas and quench solenoid valves are open and

the liquid line solenoid valve cycles on the demand of

the controller.

The hot gas bypass valve allows refrigerant to ﬂ ow

from the discharge line directly to the suction line.

The hot gas bypass entering the suction side of the

compressor would raise the operating temperature

of the compressor to a point where failure could

occur. To prevent overheating of the compressor, a

small amount of liquid refrigerant passes through the

quench valve and mixes with the hot gas entering the

compressor, maintaining normal compressor suction

pressure and temperature.

The full ﬂ oating hot gas bypass system provides

freeze protection for the evaporator coil by limiting

the minimum refrigerant pressure, preventing the

surface temperature of the evaporator coil from

dropping below 32°F. The hot gas (discharge)

regulating valve has a normal control setting at 50-55

psig (suction pressure) read from the suction (low)

side of the compressor as it operates in full hot gas

bypass operation. The valve is factory set and no

adjustment should be necessary. If adjustment is

required, remove the adjustment cap from end of the

valve. Using a 5/16 inch Allen wrench, turn clockwise

to increase pressure or counterclockwise to lower

pressure.

CAUTION

Do not exceed 20°F superheat. Exceeding this

temperature may cause failure of the compres-

sor.

The quench valve normal control setting is 20°F

superheat (when there is no call for cooling). The

valve is factory set and no adjustment should

be necessary. If adjustment is required, remove

adjustment cap from the valve. Turn the adjusting

stem clockwise to increase superheat and

counterclockwise to decrease the superheat.

2-25

1 2 ... 31 32 33 34 35 36 37 38 39 40 41 ... 59 60

Commentaires sur ces manuels

Pas de commentaire

CeilAir DX Series Manuel de l'opérateur Page 36

Commentaires sur ces manuels

Produits connexes et manuels pour Climatiseurs à système divisé CeilAir DX Series