Ingersoll-Rand EP 20-ESP, Руководство оператора/инструкция по эксплуатации и перечень запасных частей

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3.6 SETTING NEMA 4 PRESSURE SWITCH
1. Open isolation valve, allowing control system to
sense “line” pressure.
2. Start the compressor.
The compressor should load if the line pressure is
lower than then the maximum discharge pressure stat-
ed on the compressor data plate. It may be necessary
to vent air from customer system load unit.
3. Slowly close the isolation valve allowing the air line
pressure to rise to the maximum discharge pressure or
“trip” setting of the pressure switch.
4. OPERATING RANGE ADJUSTMENT: Turn lock nut
on adjustment screw “A” counterclockwise to loosen.
Turn adjustment screw “A” clockwise to raise upper and
lower pressure settings. To decrease the upper pres-
sure settings, turn “A” counterclockwise. The approxi-
mate upper pressure setting is shown by an indicator in
the left window between the calibration scales on the
nameplate. When the proper setting is reached, tighten
the lock nut on screw “A” clockwise.
5. DIFFERENTIAL ADJUSTMENT: Remove the front
cover. When the differential screw “B” is flush with the
enclosure base, the control will function at minimum dif-
ferential. To increase the differential, turn adjustment
screw “B” clockwise. This will decrease the lower set-
ting only. The higher setting will not change. Similarly,
to decrease the differential turn the differential adjust-
ment screw “B” counterclockwise. This will raise the
lower setting only.
Condensed instructions can be found on the inside of
the front cover of the switch.
NOTE: The use of a pressure gauge is desirable
when setting the control.
6. After the desired setting has been accomplished,
mount the cover and tighten the four cover screws 6-8
in. lbs. thereby compressing the gasket seal.
CAUTION
The adjustment screw “A” should not be forced
beyond the range of the control indicated on the
calibrated scale. The adjustment screw “B”
should never extend above the base of the enclo-
sure nor be adjusted beyond the maximum speci-
fied differential of the control.
7. Vent air from customer system to confirm switch
operation is satisfactory.
8. Place unit in service.
Operating variables in a system may cause changing
pressure requirements. It is recommended that a peri-
odic inspection of the gauge pressure be made and
the pressure control adjusted to compensate when
necessary for these changes.
FIGURE 3.6-1 NEMA 4 PRESSURE SWITCH (1PS)
CONTACT
BLOCK
UPPER PRESSURE
SETTING INDICATOR
DIFFERENTIAL
PRESSURE
ADJUSTMENT
SCREW “B”
LOCKING NUT
OPERATING
RANGE
ADJUSTMENT
SCREW “A”
GROUND
SCREW