Gardner Denver AirSmart VS135A, Operating And Service Manual

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13-18-607 Page 27
Blow Down Valve (P)
- This (two-way solenoid) device vents compressed air from the air/oil sump.
During compressor operation (e.g., compressors are running or they have temporarily stopped due to line
pressure reaching unload pressure); the blow down valve remains energized (closed) and the air/oil
reservoir remains pressurized. When compressor operation is halted (e.g., by use of the red
“STOP”
controller button, by loss of electrical energy, or by a shutdown condition), the valve is de-energized
(normally open state) and the air/oil reservoir is blown down.
Oil Flow Control Valve (U) – This (normally open, two-way solenoid) device reduces the flow of injection
oil the compressor. Valve U is normally held open (de-energized) and is closed (energized) to reduce the
flow of injection oil to raise the discharge temperature of the compressor during operational conditions
such as cold ambient temperature or low package load levels.
Oil Flow Control Valve (V) – This (normally open, two-way solenoid) device increases the flow of
injection oil the compressor. Valve V is normally held closed (energized) and is open (de-energized) to
increase the flow of injection oil during the start-up phase of package operation, thus allowing faster build-
up of compressed air in the sump.
Check Valve – Auxiliary Purge (Z) –
This device supplies air to the compressor inlet during operation
which requires the inlet valve to remain closed (e.g., unloaded running).
Air Filter Vacuum Switch (O) -
This device monitors the vacuum pressure at the discharge side of the
inlet air filter. When air filter vacuum reaches 30
” of water column, it triggers an air filter service
notification via the AirSmart controller.
Shuttle Valve (AA) –
This device allows fast operation of the Inlet Feed Valve (C) even when the sump is
depressurized.
Shaft Seal Drain Valve (X) –
This device allows the collection of oil bypassing the compressor shaft seal,
as well as its return into the compressor inlet. It is a 3-way solenoid valve which in its normally closed
state (de-energized), it allows the collection of shaft bypassed oil in a nylon tube connected to its exhaust
port. In its open state (energized), the valve drains the collection tube with a short blast of compressed
(air tapped from the dry-side of the oil sump) and routed to the compressor inlet. The valve is powered by
the AirSmart controller, via its built-in
“Drain Close/Open Intervals” logic usually dedicated to actuate the
condensate drain valve on the optional dryer modules. One (2) sec [open] interval and one (30) minute
[close] intervals are typically adequate to collect and drain shaft bypass oil - See AirSmart controller
manual 13-17-600 for further instructions.