McQuay AGR 070AS, Operation Manual

Page: 61 / 100

IOMM AGR-1 AGR 070A through 100A 61
External Alarm Annunciator Circuitry
An audible alarm can be connected to the Alarm Output terminals #19 and #28 of TB-3 of the control
panel and is highly recommended to make certain the operator is alerted to any alarm condition. This
output can also be used to alert a building automation system or other controls as required. This
circuit is a 24Vac 1.8 amp maximum load output but can be used as a dry contact or another voltage
by rewiring the circuit. Refer to the unit schematic.
The alarm output can be programmed to activate when an alarm or pre-alarm condition is detected.
The alarm signal is de-energized during normal operations. During a fault alarm condition the alarm
circuit will energize and the alarm status light will be on. During a pre-alarm condition the alarm
output and status light will pulse “on” for one-half second and “off” for four seconds.
Note: The alarm signal is not active during a power failure and will not provide a “Loss of
Power” alarm.
PC Connection
The MicroTech controller can be connected to an IBM or IBM compatible computer for local or
remote system monitoring. Communication network wiring uses low voltage shielded twisted pair
cable (Belden 8760 or equal). The network uses the RS232 communications standard with a
maximum cable length of 50 Feet. An RS232/485 adapter may be used to allow for cable runs to
5000 feet.
Telephone line
If remote access and monitoring of the unit is chosen, then a voice quality direct dial telephone line is
required. The line must be a dedicated line and used only for modem access. The phone line must be
terminated with a standard RJ-11 modular phone plug.
Software Identification
Control software is factory installed and tested in each panel before shipment. The software is
identified by a program code printed on a small label attached to the controller. The software version
may also be displayed on the keypad display by viewing the menu items in the Misc. Setup menu.
The software “version” is the last three digits of the software identification code.
Example of typical software identification: AGR2E01A
Controller Inputs /Outputs
Analog Inputs
Analog inputs are used to read the various temperatures and pressures on the chiller as well as any
customer supplied 4-20mA reset signals. The controller’s internal regulated 5 Vdc and 12 Vdc
supplies provide correct operating voltage for the sensors. See Table 18 for details.
Table 18, Analog Inputs
Input LED Description Location Range Resolution
0 0 Leaving Chilled Water Temp Leaving Chw nozzle -40 to 263°F 0.1°F
1 1 Circuit #1 Evap Pressure Circuit #1 Suction Line 0 to 145 psi 0.1 psi
2 2 Circuit #2 Evap Pressure Circuit #2 Suction Line 0 to 145 psi 0.1 psi
3 3 Circuit #1 Cond Pressure Compressor Discharge Line- 20 to 450 psi 0.5 psi
4 4 Circuit #2 Cond Pressure Compressor Discharge Line- 20 to 450 psi 0.5 psi
5 5 Voltage Ratio Signal EnGinn Power Supply 4.1 to 5.1 Vdc --
6 6 Chw Water Reset Supplied by others 4 to 20 mA DC --
7 7 Demand Limit Signal Supplied by others 4 to 20 mA DC --
8 8 Entering Evap Water Temp Entering Chw Nozzle -40 to 263°F 0.1°F
9 9 Entering Cond Water Temp Enter Cond Water Nozzle -40 to 263°F 0.1°F
10 10 Leaving Cond Water Temp Leaving Cond Water Nozzle -40 to 263°F 0.1°F
11 11 % Total Unit Amps Control Cabinet 0 to 4 Vdc --
12 12 Circuit #1 Suction Temp Circuit #1 Suction Line -40 to 263°F 0.1°F
13 13 Circuit #2 Suction Temp Circuit #2 Suction Line -40 to 263°F 0.1°F
14 14 Circuit #1 Liquid Line Temp Circuit #1 Liquid Line -40 to 263°F 0.1°F
15 15 Circuit #2 Liquid Line Temp Circuit #2 Liquid Line -40 to 263°F 0.1°F