Technical description
DRYPOINT® RA HT 20-350 NA UL
23
11.12 Refrigerant pressure switches LPS
– HPS – PV
To ensure the operational reliability and the protection of the dryer, a series of pressure switches are installed in the gas
cycle.
LPS :
Low-pressure guard on the suction side of the compressor, which is triggered when the pressure drops below
the predetermined value. The values are reset automatically as soon as the nominal conditions are re-
established.
Calibrated pressure :
R 407 C
Stop 24.7 psig (1.7 barg) - Restart 39.2 psig (2.7 barg)
HPS :
The high-pressure control unit on the discharge side of the compressor is activated when the pressure exceeds
the predetermined value. It has a manual reset button on the control itself.
Calibrated pressure :
R 407 C
Stop 435 psig (30 barg) - Manual reset P<334 psi (P<23 bar)
PV :
Fan control pressure switch which is installed on the discharge side of the compressor. It keeps the
condensation temperature and pressure constantly in the range of the preadjusted limit values
Calibrated pressure :
R 134.a
Start 160 psig (+7.25 / -0 psi) [11 barg (+0.5 / -0 bar)]
Stop 116 psig (+0 / -7.25 psi) [8 barg (+0 / -0.5 bar)]
R 407 C
Start 261 psig (+7.25 / -0 psi) [18 barg (+0.5 / -0 bar)]
Stop 203 psig (+0 / -7.25 psi) [14 barg (+0 / -0.5 bar)]
11.13 Safety temperature switch TS
To ensure the operational safety and the soundness of the dryer, a safety
temperature switch (TS) is installed at the refrigeration cycle. In the event that the
pressure gas temperature is too high, the sensor of the temperature switch will stop
the refrigerating compressor to prevent the pressure gas temperature getting too
high.
The temperature switch is reset manually, but only when the normal operating
conditions are reached again. Unscrew the cover (see pos. 1 in the illustration) and
press the reset button (see position 2 in the illustration).
TS setting :
temperature 235,4°F (+0/-10°F) [113°C (+0 / -6 °K)]
11.14 Aftercooler safety thermo-switch TSA
To guarantee the operating safety and the integrity of the dryer, an aftercooler
thermo-switch (T
SA
) is installed on the after cooler circuit. In case of unusual
temperatures the thermo-switch sensor behind the after cooler, stops the air
compressor.
T
SA
setting :
temperature 163,4°F (+0 / -10°F) [73 °C (+0 / -6 °K)]
1
2
PQ
S0005
PQS
009
0
Summary of Contents for DRYPOINT RA HT 100-P NA UL
Page 19: ...DRYPOINT RA HT 20 350 NA UL 19 10 2 Technical data DRYPOINT RA HT 150 350 NA E 1 230 60 UL ...
Page 34: ...Appendices 34 DRYPOINT RA HT 20 350 NA UL 13 1 2 Dryers Dimensions DRYPOINT RA HT 75 NA UL ...
Page 35: ...Appendices DRYPOINT RA HT 20 350 NA UL 35 13 1 3 Dryer dimensions DRYPOINT RA HT 100 NA UL ...
Page 36: ...Appendices 36 DRYPOINT RA HT 20 350 NA UL 13 1 4 Dryer dimensions DRYPOINT RA HT 150 NA UL ...
Page 46: ...Appendices 46 DRYPOINT RA HT 20 350 NA UL 13 3 2 Electric diagram DRYPOINT RA HT 20 50 NA UL ...
Page 47: ...Appendices DRYPOINT RA HT 20 350 NA UL 47 13 3 3 Electric diagram DRYPOINT RA HT 75 100 NA UL ...
Page 48: ...Appendices 48 DRYPOINT RA HT 20 350 NA UL 13 3 4 Electric diagram DRYPOINT RA HT 150 NA UL ...
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