McQuay AGZ 035A, Инструкция по установке, эксплуатации и обслуживанию

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84 AGZ 035A through 065A IOMM AGZ-3
Troubleshooting Analog Inputs
An analog input, such as a temperature sensor, is connected to the ADI board. The analog input is
then conditioned by the ADI board. The conditioned input is transferred to the MCB via a ribbon
cable.
Analog Input not Read by the MCB
If the MCB appears to be functioning properly and the analog input is not being read by the MCB,
perform the following procedure:
1. Try cycling power to the controller by opening and then closing circuit breaker CB1.
2. Check the ribbon cable, power wiring connector, and the field wiring connections from the
analog input device. Look for bent pins, cable on backwards, or mis-wires. Restore power after
reconnecting all cables and wires.
3. If the problem persists, try swapping a known good ribbon cable or analog input device. Swap
these components separately to isolate the problem. Remove power from the controller before
disconnecting the suspect component, and restore power after connecting the replacement
component. If the problem persists, it is likely that the MCB is defective.
Troubleshooting Digital Inputs
A digital input device is connected to the ADI board. 24Vac, supplied by transformer T2, is sent to
the digital input device via a supply wire. When a contact in the digital device makes, a return signal
is sent back to the ADI board. The signal is then conditioned by the ADI board. The conditioned
digital input is then sent to the MCB via a ribbon cable.
Digital Input not Read by the MCB
If the MCB appears to be functioning properly and the digital input is not being read by the MCB,
perform the following procedure:
1. Try cycling power to the controller by opening and then closing circuit breaker CB1.
2. Check the ribbon cable, power wiring connector, and the field wiring connections from the digital
input device. Look for bent pins, cable on backwards, or mis-wires. Restore power after
reconnecting all cables and wires.
3. If the problem persists, try swapping a known good ribbon cable or a digital input device. Swap
these components separately to isolate the problem. Remove power from the controller before
disconnecting the suspect component, and restore power after connecting the replacement
component. If the problem persists, it is likely that the MCB is defective.
Troubleshooting Output Boards
Each output on the Output Board consists of a solid-state relay, an LED, 5-amp fuse, and an MOV
(metal oxide varistor).
Normally, when the MCB commands an output to energize, the solid-state relay contacts will close
and the LED will glow. The contacts of each solid-state relay are in series with a 5-amp fuse. These
fuses resemble small resistors and are located on the board adjacent to the relays they serve (see
Figure 4). The fuses are pressed into place. They can be removed with needle nose pliers. The MOV,
which is located on the underside of the output board, protects the solid-state relay from high transient
voltages. MOVs are part of the output board and cannot be replaced.
Following are troubleshooting procedures for various symptoms of output board problems:
Note: It should be possible to determine whether a solid-state relay is defective by using
these procedures.