McQuay AGS 225D, Operating Manual

Page: 50 / 82

50 OM AGSD-1
When EXV control is set to manual, the EXV position is equal to the manual EXV position
setting. If set to manual when the compressor state transitions from run to another state, the
control setting is automatically set back to auto.
Compressor Status Enable Output
Each circuit will have its own digital output enabled while that circuit is operating. Any
time the compressor starter output is on, the status enable output will be on for that
compressor .
Economizer Control
The economizer is activated when the circuit state is Run and the slide target exceeds 95%.
It turns back off when either the circuit goes a state other than Run or the slide target drops
below 60%.
Figure 8, Economizer Piping
Filter
Drier
SV
SV
Economizer
To
vaporator
To
Compressor
Interstage
TXV
EXV
From
Condenser
SV
Solinoid
Valve
Ball
Valve
EXV
Electronic
Expansion
Valve
TXV
Thermal
Expansion
Valve
Legend