Full Load Mode - 50 To 100 Psig (3.4 To 6.9 Bar); Modulating Mode - 100 To 110 Psig (6.9 To 7.6 Bar); Unload Mode- In Excess Of 110 Psig (7.6 Bar); Load / No Load Control - Sullair 3007 Operators Manual & Parts Lists

Full Load Mode - 50 to 100
PSIG (3.4 to 6.9 BAR)
When the compressed air pressure rises above 50 psig
(3.4 bar), the minimum pressure valve opens allowing
compressed air to flow into the service line. From this point
on, the line air pressure is continually monitored by the WS
Controller. The pressure regulator and the solenoid valve
remain closed during this phase. The inlet valve is in the
fully open position as long as the compressor is running at
100 psig (6.9 bar) or below.
Modulating Mode - 100 to 110
PSIG (6.9 to 7.6 BAR)
If less than the rated capacity of compressed air is being
used, the service line pressure will rise above 100 psig
(6.9 bar). The pressure regulator valve gradually opens,
directing air pressure to the inlet control valve, reducing air
entering the compressor until it matches the amount of air
being used. The control system functions continually in
this manner between the limits of 100 to 110 psig (6.9 to
7.6 bar) in response to varying demands from the service
line.
The integrated inlet valve has an orifice which vents a small
amount of air to the compressor inlet when the pressure
regulator controls the inlet control valve. The orifice also
bleeds any accumulated moisture from the control lines.
Unload Mode- In Excess of 110
PSIG (7.6 BAR)
When a relatively small amount or no air is being used, the
service line pressure continues to rise. When it exceeds
110 psig (7.6 bar), the WS Controller control system de-
energizes the solenoid valve allowing receiver tank air
pressure to be supplied directly to close the inlet valve.
Simultaneously, the solenoid valve sends a pneumatic
signal to the blowdown valve. The blowdown valve opens
SULL AIR
® ®
3000-4500 Operator's Manual and Parts List
to the atmosphere, located in the compressor receiver
tank, reducing the receiver tank pressure to approximately
17 psig (1.2 bar). The check valve in the air service line
prevents line pressure from returning to the receiver tank.
When the line pressure drops to the low setting (cut-in
pressure; usually 100 psig (6.9 bar) on low pressure (7 bar)
compressors and 125 psig (8.6 bar) on high pressure (9
bar) compressors, 150 psig (10.3 bar) on (10 bar)
compressors, 175 psig (12.0 bar) on (12 bar)
compressors), the WS Controller energizes the solenoid
valve and allows the blowdown valve to close. The re-
energized solenoid valve again prevents line pressure
from reaching the inlet control valve. Should the pressure
begin to rise, the pressure regulator will resume its normal
function as previously described.

Load / No Load Control

If desired by the customer, the compressor can be set to
operate load/no load without modulating control. This
control mode is often selected when a large amount of
compressed air storage (air tank) is available. Using the
WS Controller keypad, select "load/no load control" from
the menu. On a machine rated for 100 psig (7 bar) the
compressor will run in the full load mode up to 100 psig (7
bar). If less than the rated capacity is required, pressure
will rise above 100 psig and the WS Controller will de-
energize the solenoid valve, causing the compressor to
run in the unload mode. When the system pressure falls to
90 psig (6.3 bar), the WS Controller energizes the solenoid
valve, causing the compressor to return to the full load
mode. The compressor will thus operate to keep the
system pressure in the range of 90-100 psig (6.3 - 6.9 bar).

Automatic Operation

For applications with varied periods of time when there are
no air requirements, the WS Controller's AUTOMATIC
mode allows the compressor to shutdown (time delayed)
when no compressed air requirement is present and
restart as compressed air is needed.
DESCRIPTION
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