Door supervised input trouble.

Issue

For doors with long wire run to the controller it is very important to follow the recommendations as far as resistor tolerance and wiring distance and gauge is concerned.

 If a door still exhibits door switch trouble issues due to length etc. one possible solution is to use a resistance decade box to determine what value resistance should be used instead of the standard 10K ohms

Product Line

Andover Continuum

Environment

AC1

AC1Plus

CX9702

ACX5740

ACX5720

ACX701

ACX781

Cause

Doors with extra long run to the IOU module / controller may produce trouble condition on the supervised inputs due to wiring issue; in some cases it may be necessary to replace the 10K ohms resistor with a different value to compensate for wiring.

Please follow the procedure outline below to determine the correct resistor value to use.

Resolution

If a door exhibit supervised input trouble issues due to wire length etc. one possible solution is to use a resistance decade box to determine what value resistance should be used instead of the standard 10K ohms, when doing this it is important the find the resistance value in the middle of the range, this will avoid random trouble due to temperature variations etc if the value happens to be right at the edge of the range.

To find the correct value use the following procedure:

  1. With the door closed start with the resistance decade box at 10K ohms.
  2. While monitoring the value of the input modify the resistance (either up or down) until the input reads CLOSED. Write down this resistance value. (VAL1)
  3. Continue to modify the resistance in the same direction until the input reads trouble again, write down this value. (VAL2)
  4. Pick a resistor value that is in the middle between VAL1 and VAL2 and use this value at the door instead of the standard 10K Ohms

NOTE: for series/parallel resistor type it may be necessary to use two decade boxes to find the correct resistance value.