13–10–613 SP Page 33
FIGURE 4–7 – SHUTTLE VALVE
tion. If both valves are energized, control pressure is
relieved from the inlet piston to allow the valve to open.
Pressure Regulator – The pressure regulator is used
to supply a constant and low control pressure to pre-
vent damage to the inlet valve from “slamming.” The
regulator should be set for 25–30 psig.
Shuttle Valve (FIGURE 4–7) – Also known as a
double check valve, the shuttle valve is a device which
will take two (2) supply signals and allow the one with
the highest pressure to pass through. The shuttle valve
is used to provide control air pressure from either the
reservoir or plant air system, as required during differ-
ent operating conditions.
Purge Air Valve – The purge valve is a normally closed
two–way air actuated valve that admits purge air from
the final discharge manifold to the compressor to coun-
teract the oil knock that occurs in oil–flooded rotary
screw compressors when they are completely un-
loaded with pressure in the oil reservoir. This valve is
controlled by the same control pressure which controls
the inlet valve.
Turn Valve (Electra–Saver only) (FIGURE 4–8)– The
turn valve is a helical valve which, when rotated, opens
and closes a series of ports cast into the compressor
cylinder. When these ports are open, they direct some
of the air which would otherwise be compressed back
to the inlet, reducing both capacity and power con-
sumption.
Turn Valve Actuator (Electra–Saver only)
(FIGURE 4–9, page 34) – The turn valve actuator is a
rotary rack and pinion device which positions the turn
valve according to system demand. Filtered oil from
the compressor sump is directed to the outboard end
of the two actuating cylinders to move the rack and ro-
tate the valve. Located on the ends of the cylinders are
adjusting screws which limit the travel of the actuator.
The adjusting screw on the top adjusts the open posi-
tion of the turn valve; the bottom adjusting screw ad-
justs the full closed (full load) position of the valve. The
full load position of the actuator may be checked by re-
moving the adjusting screw at the unloaded end of the
actuator (top of the compressor) and using a rod to
push the pistons to the full load position. The rod must
be clean and free of burrs and scale. Take care not to
scrape the cylinder walls when moving the pistons.
Solenoid Valves TVC and TVO (Electra–Saver only)
– These valves control the position of the turn valve in
response to signals from the “AUTO SENTRY–ES+”
controller. With both valves de–energized, equal pres-
sure is applied to both ends of the actuator to hold it in
its present position. If TVC only is energized, the bot-
tom of the turn valve actuator is exhausted to the com-
pressor inlet cavity, causing the turn valve to move to-
wards the full load position. If TVO only is energized,
the top of the turn valve actuator is exhausted to the
compressor inlet cavity, causing the turn valve to move
towards the unload position. See “AUTO SENTRY–
ES+ OPERATION” in this section for a description of
FIGURE 4–8 – TURN VALVE CONTROL
Содержание ELECTRA-SAVER EAYQ E
Страница 15: ...13 10 613 SP Page 6 DECALS 206EAQ077 212EAQ077 218EAQ077 211EAQ077 207EAQ077 ...
Страница 16: ...13 10 613 SP Page 7 DECALS 216EAQ077 217EAQ077 222EAQ077 221EAQ077 208EAQ077 ...
Страница 31: ...13 10 613 SP Page 22 FIGURE 4 2 FLOW CHART FOR SET UP PROGRAMMING ...
Страница 45: ...13 10 613 SP Page 36 FIGURE 4 10 CONTROL SCHEMATIC COMPRESSOR AT FULL LOAD 204EAY797 Ref Drawing ...
Страница 48: ...13 10 613 SP Page 39 FIGURE 4 13 WIRING DIAGRAM 202EAY546 Ref Drawing ...
Страница 75: ......
