94
IOMM ACZ/AGZ-1
Troubleshooting Analog Inputs
An analog input, such as a temperature sensor, is connected to the ADI board. The ADI board then
conditions the analog input. 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 incorrect-wiring. 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 ADI board then conditions the signal. 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 incorrect-wireing. 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 34). 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.
Summary of Contents for ACZ 045A
Page 6: ...6 IOMM ACZ AGZ 1 Figure 3 Clearance Requirements...
Page 27: ...IOMM ACZ AGZ 1 27 Figure 12 AGZ AM Single point Connection with FanTrol...
Page 28: ...28 IOMM ACZ AGZ 1 Figure 13 AGZ AM Single point Connection with SpeedTrol...
Page 29: ...IOMM ACZ AGZ 1 29 Figure 14 AGZ AM Unit Control Schematic UNT...
Page 30: ...30 IOMM ACZ AGZ 1 Figure 15 AGZ AM Staging Schematic UNT...
Page 31: ...IOMM ACZ AGZ 1 31 Figure 16 AGZ AM MicroTech Controller Schematic...
Page 32: ...32 IOMM ACZ AGZ 1 Figure 17 AGZ AM Unit Control Schematic MicroTech...
Page 33: ...IOMM ACZ AGZ 1 33 Figure 18 AGZ AM Staging Schematic MicroTech...
Page 34: ...34 IOMM ACZ AGZ 1 Figure 19 ACZ Field Connection Diagram No Capacity Control...
Page 35: ...IOMM ACZ AGZ 1 35 Figure 20 ACZ Field Wiring Diagram Capacity Control Staging...
Page 104: ...Post Office Box 2510 Staunton Virginia 24402 2510 USA 800 432 1342 www mcquay com...
