Occupancy Sensors/motion sensors

[brother]

I was reading the schematics on these occup. sensors, and im curious exactly how they do work. I always thought they had to have a 'return'/(neutral) to operate even though i have installed them with just the switch leg and hot (and groun). Since it has a beam comming out from it to 'see' move/heat isnt the manufacturer 'technically' violating the NEC when it it appears they are using the ground as the 'return' even on the low voltage ones, not to mention the 120 277 sensors.


http://www.hubbellcatalog.com/wiring/catalogpages/section-d.pdf

 

[iwire]

I believe UL allowed them to use the EGC for a while.

On others they use the voltage drop between the incoming hot and the outgoing load.

If the switch on the occupancy sensor is not marked 'Off' you can pretty much be sure that with the light off you can still get whacked if you break the splice.

 

[brother]

I believe UL allowed them to use the EGC for a while..

This is ridiculous. So the UL let them 'violate' the NEC. And even if thats true, UL and NEC are 2 seperate jurisdictions. Just because its 'UL' listed, does not mean you can install something that is against code, but i know 'politics' play their part.

On others they use the voltage drop between the incoming hot and the outgoing load. ..

now how is this working? the voltage drop scenerio.

If the switch on the occupancy sensor is not marked 'Off' you can pretty much be sure that with the light off you can still get whacked if you break the splice.

Exactly my point!

 

[iwire]

This is ridiculous. So the UL let them 'violate' the NEC. And even if thats true, UL and NEC are 2 seperate jurisdictions. Just because its 'UL' listed, does not mean you can install something that is against code, but i know 'politics' play their part.

I really don't want to get involved in the politic topic yet again.

What code section is being violated?

now how is this working? the voltage drop scenerio.

If you had a live single pole light switch in the off position and you place your meter across the switch what would happen?


Now replace your meter with a small electronic control board.

Exactly my point!

I don't like the use of the EGC but I have no problem with using the drop across the switch to run the electronics.

If a switch or any control is not marked "Off" we should not expect it to be safe to work on.

 

[brother]

What code section is being violated?.

From what i understand from your post and what i stated before, they are using the egc as a current carrying conductor(neutral). Not good and code violation. Im tired cant think of the exact article, but im sure you know it.

If you had a live single pole light switch in the off position and you place your meter across the switch what would happen?


Now replace your meter with a small electronic control board..

Ok i gotcha.

I don't like the use of the EGC but I have no problem with using the drop across the switch to run the electronics.

If a switch or any control is not marked "Off" we should not expect it to be safe to work on.

I agree we should not expected to be safe to work on, but using the egc as any type of neutral is just unsafe.

 

[iwire]

We use the Watt Stopper WS-200 Wall Switch Sensors a lot.

From the installation instructions

The ground wire must be tightly grounded for the unit to operate properly.

Thats interesting as the entire device is plastic.

 

[480sparky]

This is why the LV industry always proposes a change to the NEC every Code cycle to require the circuit neutral to be in the switch boxes....LV techs installing this stuff don't want to take the time to wire it correctly (i.e., find the proper neutral and hook it to that), so they just use the ground.

 

[iwire]

don't want to take the time to wire it correctly (i.e., find the proper neutral and hook it to that), so they just use the ground.

They don't have to find it now, the many products use the EGC, the instructions say to.

I believe it is UL looking for the change to the NEC.

 

[peter d]

I just installed a Leviton ODS-10 (or something like that) yesterday, and the ground wire was clearly labeled that it must be connected for proper operation.

 

[frenchelectrican]

This is why the LV industry always proposes a change to the NEC every Code cycle to require the circuit neutral to be in the switch boxes....LV techs installing this stuff don't want to take the time to wire it correctly (i.e., find the proper neutral and hook it to that), so they just use the ground.

480sparky.,

You have right idea about the sisuation but the issue will come up is with the resdentail area where the AFCI/GFCI requirement it may trip the unit something like this.

And i know quite few motion sensors reqired few MA to actative it.
that why i was condersering it may trip if the MA level get to the point it will trip it easly.

[ OT but pretty much right on track here one time i did remove the motion sensor switch and i ran the probe between the motion sensor yoke and ground wire and read it 277 v after i did got mild shock after that i got a habit turn off the breaker before i remove that bloody thing. ]

Merci, Marc

 

[brother]

This is why the LV industry always proposes a change to the NEC every Code cycle to require the circuit neutral to be in the switch boxes....LV techs installing this stuff don't want to take the time to wire it correctly (i.e., find the proper neutral and hook it to that), so they just use the ground.

Ok so im right!! They are using the ground as a neutral and its clearly a code violation and very dangerous. Im just suprised that no one is up in arms over this, since these manufacturers are sooo concern about our safety (TR recetacles, Afci's etc.). Why arent they made to pull a neutral like they suppose to. Neutrals are not and should not be required for the switch per NEC, however if you install a device that needs a return then you install one. Obviously they make alot more money off of these 'energy savers' and they are not gonna say anthing about it no matter how dangerous.

They don't have to find it now, the many products use the EGC, the instructions say to.

I believe it is UL looking for the change to the NEC.

After reading many of your posts I cant believe that you are ok with this Especially after all the hoopla over safety (TR receptacles etc.)! Something that is clearly against code and very dangerous. I am 'shocked' (pun intended) that UL would allow this nonsense! I went to your link and it says the ground has to be hooked up to work properly

I just installed a Leviton ODS-10 (or something like that) yesterday, and the ground wire was clearly labeled that it must be connected for proper operation.

Again, the ground is used as a neutral!! Im suprised you not up in arms over this too I dont care how small that current is, its still wrong. Am I the only one that see this as major issue??

480sparky.,

You have right idea about the sisuation but the issue will come up is with the resdentail area where the AFCI/GFCI requirement it may trip the unit something like this.

And i know quite few motion sensors reqired few MA to actative it.
that why i was condersering it may trip if the MA level get to the point it will trip it easly.

[ OT but pretty much right on track here one time i did remove the motion sensor switch and i ran the probe between the motion sensor yoke and ground wire and read it 277 v after i did got mild shock after that i got a habit turn off the breaker before i remove that bloody thing. ]

Merci, Marc

Well you just made my point! Dangerous voltage on the egc Also, remember not to work on anything live unless is absolutely necessary!!

 

[iwire]

Ok so im right!! They are using the ground as a neutral and its clearly a code violation and very dangerous.

Brother, the NEC does not apply to the manufacturers and we have to install the UL listed product per 110.3(B)

Another common example is that UL allows manufacturers to attach grounding conductors into sheet metal with sheet metal screws, if I do that it is a violation, if they do that it's OK. If you stop and think about it you can find many such examples. Another is using wire connectors per their listing, the factories jam as many conductors as they want into a lug rated for one connector if I do that it is a violation.

I already said I was not happy about it, only telling you how it is.

This is not some sort of new development, this has been ongoing for quite a while.

Before you go off on a rant keep in mind there are already tens of thousands of these devices already installed and accepted.

 

[brother]

Brother, the NEC does not apply to the manufacturers and we have to install the UL listed product per 110.3(B).

Im aware that iwire!! However the NEC does try to regulate some products from the manufacturer (i.e. 2008 NEC 422.51, Vending machines with gfci on the cord made after Jan 1 2005). Since the NEC can require this gfci on machines and manufacturers goes ahead and comply with it, then why can they not require a 'neutral' wire or terminal on these occupancy switches seperate from the egc terminal or wire?? I know why, it cuts into their bottom line (MONEY).

Another common example is that UL allows manufacturers to attach grounding conductors into sheet metal with sheet metal screws, if I do that it is a violation, if they do that it's OK. If you stop and think about it you can find many such examples. Another is using wire connectors per their listing, the factories jam as many conductors as they want into a lug rated for one connector if I do that it is a violation.).

Im aware of that too, I was just making a point about some of these so called, "lets save the children TR Afci electrical safety" song birds out there not saying anything about something thats been going on for a while and still going on even with all the hard facts and DATA we got on this dangerous issue (egc as a neutral) unlike the A.F.C.I. (All For Cashing In). And as for all of those examples you gave and even those you did not mention IMHO does not come anywhere near as dangerous or is as more of a safety issue than installing/manufacturing products that use the egc as a neutral in this modern age residential housing. NEC is about 'minimal electrical safety' but they wont saying anything about this.

I already said I was not happy about it, only telling you how it is.

This is not some sort of new development, this has been ongoing for quite a while..).

Its good you not happy about it and thanks for telling me how it is, even though i already knew 'how it is' when it comes to the UL getting in bed with the manufactorers.

Before you go off on a rant keep in mind there are already tens of thousands of these devices already installed and accepted.

Too late, I had already went on a 'rant' when i first started this post. LOL
Just because there are thousands of these things out there and they are accepted does not make it right. If the NEC can make the new house ranges and dryers seperate their egc from the neutral, then im sure they can have some influence on this issue. Thanks for the replies.

 

[iwire]

Since the NEC can require this gfci on machines and manufacturers goes ahead and comply with it, then why can they not require a 'neutral' wire or terminal on these occupancy switches separate from the egc terminal or wire?? I know why, it cuts into their bottom line (MONEY).

You know I am getting a bit tired of reading accusations with nothing to back them up.

What cuts into who's bottom line?

Im aware of that too, I was just making a point about some of these so called, "lets save the children TR Afci electrical safety" song birds out there not saying anything about something thats been going on for a while and still going on even with all the hard facts and DATA we got on this dangerous issue (egc as a neutral) unlike the A.F.C.I. (All For Cashing In). And as for all of those examples you gave and even those you did not mention IMHO does not come anywhere near as dangerous or is as more of a safety issue than installing/manufacturing products that use the egc as a neutral in this modern age residential housing. NEC is about 'minimal electrical safety' but they wont saying anything about this.

You have absolutely no data to support your claims, all you have above is a rant.

Have you one bit of information that supports your thoughts that this use of the EGC has lead to injuries?

Its good you not happy about it and thanks for telling me how it is, even though i already knew 'how it is' when it comes to the UL getting in bed with the manufacturers.

Another accusation without any documentation at all.

Too late, I had already went on a 'rant' when i first started this post.

It seems to be you usual way to go...:roll: :grin:

Just because there are thousands of these things out there and they are accepted does not make it right.

No but it would have a trail of injuries behind it if it was as big a deal as you seem to feel it is.

If the NEC can make the new house ranges and dryers separate their egc from the neutral, then im sure they can have some influence on this issue.

Say what?

The NEC did not make any changes to ranges and dryers, they made changes to the branch circuits supplying them, if you buy either a range or dryer today they can still be wired either 3 wire or 4 wire.

Considering your extreme displeasure with the NEC I assume you must have sent in many proposals to change the items that you feel are wrong.

 

[JohnJ0906]

I was reading the schematics on these occup. sensors, and im curious exactly how they do work. I always thought they had to have a 'return'/(neutral) to operate even though i have installed them with just the switch leg and hot (and groun). Since it has a beam comming out from it to 'see' move/heat isnt the manufacturer 'technically' violating the NEC when it it appears they are using the ground as the 'return' even on the low voltage ones, not to mention the 120 277 sensors.


http://www.hubbellcatalog.com/wiring/catalogpages/section-d.pdf

I wonder how much current they put onto the EGC? Enough to trip an AFCI?

 

[brother]

You know I am getting a bit tired of reading accusations with nothing to back them up.

What cuts into who's bottom line? .

Well just think LOGICALLY, Do you really think that if afci were not required that they would make as much money as them being required?? do you really think if these 'fancy' occupancy switches were required to be hooked up to a neutral and the NEC did not require the neutral at the switch, and the average homeowner knew it would costs more to pull wire/circuit just to have that fancy switch you think they would sell as many?? They would still sell alot, no doubt, but definetly not as many IMHO.

Brother says : while and still going on even with all the hard facts and DATA we got on this dangerous issue (egc as a neutral) unlike the A.F.C.I. (All For Cashing In).

iwire says:
You have absolutely no data to support your claims, all you have above is a rant

Have you one bit of information that supports your thoughts that this use of the EGC has lead to injuries?.

I cannot believe you just made that comment.
First off, when i said that 'issue' of the egc as a neutral I was not limiting myself to the occupancy switches. I was speaking in general. Yes there have been documented cases where someone miss wired something and egc was the neutral and not used to clear a fault! Im not gonna dig it up for you im sure you can find it yourself. A situation that comes to mind is when A friend of mine told me about a guy that miswired a mobile home. He used a 3 wire instead of a 4 wire. One day it was raining and the homowner was comming home and and stuck his key in the door and go a shock. It didnt kill them but it hurt. Come to find out that mobile home had the egc used as a neutral and the skin of that metal mobile home was 120v!! Contrary to popular belief, current dont just take the path of least resistance, the current flows in PORPORTION to the resistance of all paths. Just on that rainy day apparently there was less resistance in the ho than the egc back to the panel.

brother says:
...the UL getting in bed with the manufacturers

Iwire says:
Another accusation without any documentation at all.
.

Another comment i cant believe you said. No im not the 'batman detective' nor have i talked to 'deep throat' from watergate, but the passage of certain products and requirements speaks for themselves. I know you not naive enuff to believe that all the UL listed products is passed 'unbiased' and 'fair' .

No but it would have a trail of injuries behind it if it was as big a deal as you seem to feel it is.

Like i said the 'issue' of the egc as a neutral was not limited to the o.s. and yes there are a 'trail' of injuries behind it see example above.

Say what?

The NEC did not make any changes to ranges and dryers, they made changes to the branch circuits supplying them, if you buy either a range or dryer today they can still be wired either 3 wire or 4 wire.

Considering your extreme displeasure with the NEC I assume you must have sent in many proposals to change the items that you feel are wrong.

Ok that is true about the range/dryer that the NEC did not DIRECTLY make them do it. But the requirement to the branch circuit of seperating the neutral and egc forces the homeowner to purchase a 4 wire cord and thus having the manufacturers instructions to remove the egc from the neutral terminal in the product. So it took care of that issue indirectly. As for the proposals, I will be submitting some, but i like coming to the mike holt guys just to bounce off my displeasure cause someone will always challage me back, making me think even deeper and see things from a different angle Even you iwire LOL .