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Old 12-21-2012, 10:20 AM   #16
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House Ground not strong enough


fowlkesfamily, please post the name and model of the switch you have. Also, please tell us exactly what wires and splices exist in the box.

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Old 12-21-2012, 11:00 AM   #17
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House Ground not strong enough


Not necessarily the sensor that the OP has, but follow the link in Post #7 for an example of a neutral-less occupancy sensor.

In fact, it comes in two versions, one where a neutral is present and one which uses the ground wire.
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Old 12-21-2012, 12:48 PM   #18
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Originally Posted by Dave632 View Post
Not necessarily the sensor that the OP has, but follow the link in Post #7 for an example of a neutral-less occupancy sensor.

In fact, it comes in two versions, one where a neutral is present and one which uses the ground wire.
I realize there are two versions, but they cannot use the ground as a neutral. As stated in those instructions: "These versions use the ground connection to
complete the relay circuit while producing a minimal amount of ground leakage."

They are calling it "ground leakage" as opposed to ground current. How they do this is beyond my knowledge, but I would think they'd be taking far too much of a risk imposing actual current on the ground.

I guess this is what electures was referring to.
Thanks.
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Old 12-21-2012, 12:56 PM   #19
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They are calling it "ground leakage" as opposed to ground current. How they do this is beyond my knowledge, but I would think they'd be taking far too much of a risk imposing actual current on the ground.
Yeah, I'm surprised the UL listed it.
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Old 12-21-2012, 01:09 PM   #20
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House Ground not strong enough


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I'm sorry, but I don't buy it.
There should be NO current on the equipment ground, period, and I'm not sure what the EG has to do with the grounded conductor (neutral) being required in switch boxes. I can see your point only in that dumb people were using the EG as a neutral in places where a switch loop existed and an OC switch was install that required a neutral. This creates a tiny amount of circuit current on the EG systems which is NOT good.

The equipment ground and the neutral are two different things. I have never seen an OC switch that required an equipment ground to work properly.
Copied and pasted from an IAEI article found here;

Grounded Circuit Conductors at Switch Locations

New requirements in the latest edition of the Code requires that where switches control lighting loads such as luminaires, ceiling paddle fans, etc., and are supplied by a general-purpose branch circuit that is grounded, the grounded circuit conductor (generally neutral conductor) for the controlled lighting circuit is required to be provided at the switch location. An exception to this requirement permits the grounded (neutral) conductor to be omitted from the switch enclosure where one of the following conditions applies:
(1) Conductors for switches controlling lighting loads enter the box through a raceway, with the raceway having sufficient cross-sectional area to accommodate adding a grounded conductor at a later date or (2) where cable assemblies such as Type NM cable enter the box through a framing cavity that is open at the top or bottom on the same floor level, or through a wall, floor, or ceiling that is unfinished on one side [see NEC 404.2(C)].
Many electronic lighting control devices, such as occupancy sensors require a standby current to maintain a ready state of detection for the function of these devices. This also allows immediate switching of the load to the “on” condition. These types of devices require standby current when they are in the “off” state as well. These devices typically utilize the grounded conductor for the standby current flow. In some situations, such as where the grounded conductor is provided at the lighting outlet location, a grounded conductor is typically not provided in the switch box for switches controlling lighting loads. When a snap switch is replaced with an occupancy sensor at a later date, installers have typically employed the equipment grounding conductor for the standby current of these control devices. This is not a good practice due to the introduction of circulating current onto the equipment grounding conductor. Occupancy sensors are permitted by UL 773A to have a current of up to 0.5 mA on the equipment grounding conductor. Current flowing at the load when the device is presumed to be off could create a potential risk to installers.
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Old 12-22-2012, 05:51 PM   #21
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House Ground not strong enough


So I tried to run a new ground wire from an incoming copper pipe to the ground on the sensor, but the light still remains on. I have included 2 pictures of the sensor.
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Old 12-22-2012, 06:35 PM   #22
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House Ground not strong enough


What kind of bulb is in the light fixture? If compact fluorescent, please try an incandescent -- just to eliminate one more variable.

As for grounding to the copper water pipe, was it hot or cold? Hot will usually not work as there's typically a dielectric coupling at the water heater.
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Old 12-28-2012, 01:37 PM   #23
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House Ground not strong enough


I changed the bulb from a compact fluorescent to incandescent. I also verified that the additional ground wire I ran from the water pipe was connected to the COLD water pipe. Light still on.

I just bought another occupancy switch (exactly the same type) and I'll install that next to see if the switch is defective. More news later.
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Old 12-28-2012, 08:51 PM   #24
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House Ground not strong enough


Somebody correct me if this is a crazy idea because it might be but...

Is there a neutral wire in the box you're placing the occupancy sensor in? If there is, you may be able to try taking the ground wire to that instead of a copper pipe to test it out.

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