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Advice on shielding issue

Advice on shielding issue

Advice on shielding issue

(OP)
Hello,
I am working on a project wherein we have a control panel 100' away from some equipment.  The equipment is outside, and the cabling is SOOW portable cord.  There is a 6 conductor cable with single overall shield bringing the field signals to the main control panel.  In that cable I have two field mounted estops, each connected to a 120VAC control relay in the cabinet.  Also in that cable, I have a 4-20mA signal for an analog signal.  The analog signal goes to a PLC which does have a 60Hz filter on the input.  Because I need to use SOOW (I cannot use tray cable), I cannot get individual shields.  I am concerned about how much error I might get in the analog signals from the ESTOP signals.  The ESTOP relays (2) are standard IDEC relays which draw around 15mA each.  They will be energized all the time.  The analog signal is not for control, only monitoring.  So there is an accuracy issue, not a safety issue.

Am I likely to have a problem with this?  

thanks for your help

RE: Advice on shielding issue

Any possibility of using a DC control relay? The likely interfering signals either go away or are at worst of a transient nature (and could probably be filtered out if necessary).
  

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RE: Advice on shielding issue

(OP)
That is an option, and I might go that route.  It would require some changes in the drawings, but that's about it.  I would prefer to leave it as is.  I just don't know how to calculate the amount on interference I should expect.

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