McQuay AGZ026BS, Installation, Operation And Maintenance Manual

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IOMM AGZ-5 AGZ 026B through 130B 55
Overview
MicroTech II controller’s state-of-the-art design not only permits the chiller to run
more efficiently, but also can simplify troubleshooting if a system failure occurs.
Every MicroTech II controller is programmed and tested prior to shipment to facilitate
start-up.
Operator-friendly
The MicroTech II controller menu structure is separated into three distinct categories
that provide the operator or service technician with a full description of 1) current unit
status, 2) control parameters, and 3) alarms. Security protection prevents unauthorized
changing of the setpoints and control parameters.
MicroTech II control continuously performs self-diagnostic checks, monitoring system
temperatures, pressures and protection devices, and will automatically shut down a
compressor or the entire unit should a fault occur. The cause of the shutdown will be
retained in memory and can be easily displayed in plain English for operator review.
The MicroTech II chiller controller will also retain and display the date/time the fault
occurred. In addition to displaying alarm diagnostics, the MicroTech II chiller
controller also provides the operator with a warning of limit (pre-alarm) conditions.
General Description
AGZ-B Inputs/Outputs
Table 35, Analog Inputs
No. Description Type Signal Source Range
1 Evaporator Refrigerant Pressure #1 C1 0.1 to 0.9 VDC 0 to 132 psi
2 Evaporator Refrigerant Pressure #2 C2 0.1 to 0.9 VDC 0 to 132 psi
3 Condenser Refrigerant Pressure #1 C1 0.1 to 0.9 VDC 3.6 to 410 psi
4 Leaving Evaporator Water Temperature UT
NTC Thermister
(10k@25°C)
-58 to 212°F
5 Outside Ambient Temperature UT
NTC Thermister
(10k@25°C)
-58 to 212°F
6 Condenser Refrigerant Pressure #2 C2 0.1 to 0.9 VDC 3.6 to 410 psi
7 Reset of Leaving Water Temperature UT 4-20 mA Current 0-(10 to 80°F)
8 Demand Limit UT 4-20 mA Current 0-100 % Load
9 Compressor Suction Temperature #1 C1
NTC Thermister
(10k@25°C)
-58 to 212°F
10 Compressor Suction Temperature #2 C2
NTC Thermister
(10k@25°C)
-58 to 212°F
NOTE: C1 = Refrigerant Circuit #1, C2 = Refrigerant Circuit #2, UT = Unit
Table 36, Analog Outputs
No. Description Output Signal Range
1 Fan #1 VFD 0 to 10 VDC 20 to 60 Hz
2 Fan #2 VFD 0 to 10 VDC 20 to 60 Hz