4
TROUBLESHOOTING
Before proceeding through the troubleshooting section, ensure that all device latches are not
binding against their corresponding strikes. A bound latch can cause sluggish electric pullback or
prevent pullback entirely.
Power Limited Outputs
All outputs to the 781N are power limited. Depending on the output, if a short circuit or an over load
condition should occur, the output will either shut off entirely or go into a safe current limiting state.
IMPORTANT!: THE MAXIMUM RATED LOAD FOR ALL OUTPUTS COMBINED IS 2.0 AMPS,
INCLUDING 250mA (MAX.) FOR EACH AUXILIARY OUTPUT.
The outputs to Device One (TB3, terminals 5 & 6) and Device Two (TB3, terminals 11 & 12) will
completely shut down to 0 volts when a short circuit across the output occurs or when the load
exceeds 5 amps. To reset the output, the short circuit or overload must first be located and removed.
Next, momentarily switch off the outputs by opening the contacts across input terminals 1 & 2 or 7
&8, whichever is used. Before switching outputs back on, ensure the load does not exceed the
maximum current ratings.
Both auxiliary outputs will go into a current limiting state when the load exceeds approximately 2.0
amps or in the event of a short circuit. The current is reduced to a safe level when either of these
conditions occur. The output voltage will automatically return to its normal level when the short
circuit or overload condition is removed and replaced by a load falling under the maximum current
rating.
Symptom:
Neither DEVICE ONE or DEVICE TWO pulls back after the control switch is activated.
Possible Causes:
1. The power limited output to Device 1 or Device 2 (or both) may have shut down.. When this
happens, the field wires that are run to the exit device are probably shorted together against the
conduit, door frame or electric hinge.
2. The slow blow 4 amp fuse (Littlefuse #239.004) inside the exit device has blown. The most likely
cause would be reversed polarity of the exit device red and black leads: RED = "+"; BLACK = "-".
(Refer to the wiring diagram for proper connection.) Other possible causes may be shorted wires
in the solenoid assembly or a defective pulse module.
3. An open connection in the field wiring between the power supply and control switch used for
activating latch pullback.
4. A defective control switch.
5. An open connection in the field wiring between the power supply and exit device.
An ASSA ABLOY Group brand
80-9477-0781-010 (01-13)
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