McQuay AGR 080AS Product Manual

6
AGR 070A through 100A Product Manual AGR-3
Electrical Control Center
Operating and equipment protection controls and motor starting components are separately housed in a
centrally located, weatherproof control panel with hinged and key locked doors. In addition to one of
the three types of control described in the next sections, the following components are housed in the
panel:
•
Power terminal block
•
Control, input, and output terminal block
•
120V control circuit transformer
•
Optional disconnect switch with through-the-door operating handle
•
Compressor contactors (circuit breakers are available as an option) (part winding on 208/230V,
across-the-line on 380/460/575V) compressor motor inherent thermal and overload protection is
standard.
•
Optional phase voltage monitor with under/over/phase reversal protection
•
Fan contactors with separate fuse blocks
•
The standard FanTrol system controls fan staging for control of refrigerant discharge pressure.
The FanTrol system cycles condenser fans based on discharge pressure and outdoor temperature
and is suited for operation to 40°F (4.4°C).
•
The optional SpeedTrol control uses both fan cycling and fan speed control on the lead fan per
circuit and allows operation to 0°F (-18°C) outdoor temperature.
•
Mechanical high pressure cutout
Global UNT Controller (Standard on R-22)
Microprocessor based control that accomplishes unit capacity control by 6-stage cross-circuit
compressor cycling and unloading based on leaving chilled water temperature. Setpoint and control
band are easily field adjusted. Anti-cycling and stage delay timers are included. Equipment protection
controls include low refrigerant pressure, low evaporator flow (field installed flow switch), low oil
pressure, and sensor failures. Outside air temperature sensor is standard. Reset options are; outside air,
return water, remote reset, demand limit, zone temperature reset. The optional Zone Terminal control is
required to adjust the reset setpoints. The UNT control is used only with R-22.
Thirty feet of sensor cable is included, rolled up in the control panel, on remote evaporator models.
Figure 2, Standard Global UNT Controller

McQuay AGR 080AS Specifications

General

Brand	McQuay
Model	AGR 080AS
Category	Chiller
Language	English