McQuay AGR 070AS, Руководство по эксплуатации

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60 AGR 070A through 100A IOMM AGR-1
Power Wiring
The installing contractor provides the unit voltage power source, disconnect, fuses and necessary
wiring for these circuits. All wiring must conform to the National Electrical Code and applicable
local building codes. If the control power source (120Vac) or the evaporator heater power source
(120Vac) or both are supplied from a separate external supply, remove wires 540 and 545 as indicated
on the field wiring diagram.
Power Supplies
There are several internal power supplies used by the controller and related circuitry. The regulated
5 Vdc power is supplied by the controller and provides power to all analog inputs into the ADI board.
Do not use this power supply to operate external devices. A 24 Vac power supply is available for the
alarm bell option. Wire according to the field wiring diagram.
Analog Input Signals
All sensors and transducers required for normal chiller operation are installed and wired at the factory,
All optional analog signal wiring provided by the installing contractor must be twisted, shielded pair
(Belden #8760 or equal). The optional demand limit and leaving water reset signals are 4 to 20
milliamp DC signals. The resistive load that conditions the milliamp signal is a 249 ohm resistor
mounted on the ADI board at the factory.
Digital Input Signals
Remote contacts for all digital inputs into the MicroTech controller must be dry contacts suitable for
the 24 Vac control signals from the control panel. Do not connect 120 Vac power to the digital inputs.
Remote Stop/Start
If remote stop/start control is selected, remove the jumper between terminals #140 and #141 on TB-7.
When the remote stop/start switch is open, the controller will be in the “Off: Remote Sw” mode. The
unit will be enabled when the switch is closed.
Chilled Water Flow Switch
The chilled water flow switch is connected to field wiring terminals #142 and #143 on TB-7. When
the chilled water pump is enabled, the MicroTech controller checks for proof-of-flow through the
flow switch digital input.
Digital Outputs
The digital output board has normally open solid-state relays with an on-board replaceable 5 amp
fuse. The status of all outputs are shown by the individual output red LEDs.
Chilled Water Pump Relay
The optional chilled water pump relay is connected to terminal #10 and #9 on TB-2. When the unit is
enabled, the chilled water pump relay is energized. Be sure the relay coil is rated for a maximum load
of 1.8 amps at 120 Vac. There is a 5 amp fuse on the digital output board for this control circuit.