Gardner Denver AirSmart EAU99T Operating And Service Manual page 38

Overload protection is provided for each motor on full voltage and Wye Delta applications. The overloads
are adjustable and are factory set based on the motor nameplate amps and the instructions located inside
the control box door. Less starter applications utilize a control relay for control of a remote mounted
motor starter (not provided with compressor package). Wye-delta starters employ three contactors which
are controlled sequentially to provide low current starting. For wye-delta starters, the motor nameplate
amps must be first multiplied by 0.577 before using the heater table.
COMPRESSOR CAPACITY CONTROL - TURN VALVE UNITS ONLY
The capacity of the compressor is controlled by the action of the turn valve and the compressor inlet
valve.
The turn valve controls compressor delivery to match demands of 40% to 100% of the compressor's
maximum capacity. The inlet valve throttles to control compressor delivery to match demands of 0% to
40% of the compressors maximum capacity.
Example with normal setting of 100 PSIG:
Compressor Delivery
Capacity
Full
70%
40%
30%
20%
0%
Inlet Valve Position
Open
Open
Open
Closing
Closing
Closed
13-10-618
Turn Valve Position
Closed
50% Open
Full Open
Full Open
Full Open
Full Open
Page 37
Discharge Manifold
Pressure (psi)
100
100
100
103
103
103