McQuay WGS130AA: WGS140AW, Руководство по эксплуатации

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14 WGS 130A to 190A OM WGS-5
General Description
The MicroTech II controller’s design permits the chiller to run more efficiently, and it
simplifies troubleshooting if a system failure occurs. Every MicroTech II controller is
programmed and tested prior to shipment to assist in a trouble-free start-up. The MicroTech
II controller can be used to cycle fans on remote air-cooled condensers for head pressure
control when the setpoint Water Cooled=N is selected in one of the setpoint menu screens.
Water Cooled=Y sets the chiller for operation with the water-cooled condenser and activates
settings for cooling tower control. Remote evaporative condensers will have to have self-
contained, on-board, head pressure control systems.
Units of measure
Version “C”, as described in this manual, supports metric (SI) units of measure.
Inch-Pound SI

F to 0.1

F

C to 0.1

C
psi to 0.1 psi KPa to 1.0 kPa
Distributed Control
The WGS units have three MicroTech II microprocessors, a Unit Controller plus a Circuit
Controller for each of the two circuits. The Circuit Controllers are independent such that
either one will operate its circuit if the other Circuit Controller is out of service.
Operator-friendly
The MicroTech II controller menu structure is separated into three distinct categories, which
provide the operator or service technician with a full description of the following:
1. Current unit status
2. Control parameters (setpoint settings and adjustment). Security protection prevents
unauthorized changing of the setpoints and control parameters.
3. Alarm notification and clearing
The MicroTech II controller continuously performs self-diagnostic checks, monitoring
system temperatures, pressures and protection devices, and will automatically shut down a
refrigerant circuit or the entire unit if a fault occurs. The cause of the shutdown and date
stamp are retained in memory and can be easily displayed in plain English for operator
review, which is an extremely useful feature for troubleshooting. In addition to displaying
alarm diagnostics, the MicroTech II controller also provides the operator with a warning of
pre-alarm limit conditions.
Staging
The two screw compressors are loaded and staged on and off as a function of leaving chilled
water temperature, number of starts and run-hours. See Sequence of Operation beginning
on page 16.
Equipment Protection
The unit is protected by alarms that shut it down and require manual reset, and also by limit
alarms that limit unit operation in response to some out-of-ordinary condition. Shutdown
alarms activate an alarm signal that can be wired to a remote device.