Simplex 4010 Service Manual page 17

NAC Troubles,
Type Trouble Message
NAC 1 Signal Power
NAC
NAC 2 Signal Power
Card
NAC 3 Signal Power
Troubles
NAC 4 Signal Power
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Continued
Table 2-1. NAC Card and Point Troubles (continued)
Indicates a power trouble on the NAC. Check the following:
•
Check the load on the NAC in question while it is in the alarm state.
The load on each NAC must not exceed 2A. The SFIO board has
overcurrent protection for each NAC. An overloaded NAC trips this
protection and displays a NAC Signal Power Trouble for the circuit.
Unless the circuit is grossly overloaded, you should have several
seconds to measure the voltage before the protection trips. Measure
the current in either one of the following ways:
-
-
•
If the problem is with NAC 3 or 4, and they are powered by the 4010's
Expansion Power Supply (EPS), check the following:
-
-
-
-
P13 (Red
Harness)
Possible Causes / Troubleshooting
Current Draw for a Single NAC. Use a DC ammeter, connected
in series with the load, to measure the load.
Current Draw for all NACs. Measure the voltage across R150,
which is located above the LCD on the left-hand side of the SFIO.
Divide the measured voltage by .025. The result is the sum of all
NAC and auxiliary power loads.
Verify that the red shunt has been removed from connector P13
on the SFIO board.
Verify that the red (power) harness is connected to P1 on the
EPS and P13 on the SFIO board. Verify the white harness
(communication) is connected to P14 on the SFIO and P2 on the
EPS.
Remove the harness and visually inspect each female pin on
both harness connectors. Make sure that none of the pins is
pushed back into the connector. Gently tug on each wire at the
back of the connector. If a wire pulls out from the connector,
re-insert it until the pin clicks back into place. Meter each wire for
continuity.
Verify that no circuit draws more than 2A.
- +
2 1
P14 (White
Harness)
2-3
+ - + -
P1 (Red
P2 (White
Harness)
Harness)