Thanks Thanks:  0
Likes Likes:  0
Dislikes Dislikes:  0
Results 1 to 4 of 4

Thread: rewire no-neutral devices to avoid ground current?

  1. #1

    rewire no-neutral devices to avoid ground current?

    occupancy sensing switch like MS-OPS2 puts a current on the ground wire. I don't like doing this, since ground wire is not meant to carry current.

    The wiring diagram suggests connecting both the green wire and the metal face plate to the ground wire.

    If neutral wire is available, can I connect the green wire to neutral, and the metal plate to the ground?

    There is no version of this switch that requires neutral wire. There is a more expensive sensor switch that requires neutral wire.

    MS-OPS2 install manual





  2. #2
    Senior Member
    Join Date
    Nov 2014
    Posts
    222
    Did you measure a current level on the ground? Or just assuming because the device needs a ground to work that a current is present?

  3. #3
    Quote Originally Posted by Lukeetal View Post
    Did you measure a current level on the ground? Or just assuming because the device needs a ground to work that a current is present?
    Both.

    I once bought a more expensive dual-sensor lutron occupancy sensor that also did not require ground (MS-A102). I measured it and found current on the ground. I remember the current is much less than what's required to trip a GFCI.

    That is to be expected since the device requires power to work. I eventually returned it and bought a version of that sensor (MS-B102) that required neutral, and therefore did not pass a current into ground wire.

    I want to buy another occupancy sensor switch but the price of the MS-B102 has gone way up. Perhaps I bought it on sale. So I decided the cheaper MS-OPS2 is good enough. But oddly this sensor does not have a version that required neutral, like the MS-A102.

    The instruction of MS-OPS2 said the device would not work if ground is not connected. That also implies a current is flowing into ground; otherwise why would it affect whether it works or not.

  4. #4
    Authorized Lutron Contributor
    Join Date
    Dec 2015
    Posts
    181
    Hello shortcircuit,

    There is a tiny amount of current that runs through the device in the off state. The exact amount is 0.04W/hr. The reason the ground connection is required is that the power supply inside of the sensor needs to see a potential difference via the ground.

    There is absolutely no safety concern with hooking the sensor up with the ground.

Similar Threads

  1. House Has No Ground Wires
    By Oakley in forum General Discussion - CAS
    Replies: 6
    Last Post: 08-17-2016, 11:25 AM
  2. Inrush current for dimmers
    By Arsen in forum Compatibility - LED
    Replies: 1
    Last Post: 06-23-2016, 10:48 AM
  3. two wire switch no ground no neutral wires UMS-OPS6M-DV-WH
    By dfphoto in forum General Discussion - Controls
    Replies: 0
    Last Post: 11-21-2014, 03:10 PM
  4. Hybrid Keypad Neutral wire (When use it)?
    By Fabio Bortolin in forum General Discussion - HWQS
    Replies: 1
    Last Post: 11-13-2014, 04:18 PM
  5. 8ANS without a neutral
    By Craig W. in forum General Discussion - HWQS
    Replies: 0
    Last Post: 01-20-2014, 07:58 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •