ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
Recent Posts
VFD MotorFeeders
by gfretwell. 10/19/17 01:02 AM
Generator Cable Sizing
by brsele. 10/18/17 07:39 PM
What do you do?
by gfretwell. 10/17/17 01:08 AM
Good ol' copper pipe in the fuse holder trick
by HotLine1. 10/16/17 07:16 PM
Another generator question
by HotLine1. 10/16/17 07:02 PM
New in the Gallery:
Gallery Test
Popular Topics(Views)
241,402 Are you busy
177,364 Re: Forum
168,970 Need opinion
Who's Online Now
0 registered members (), 55 guests, and 9 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
#96112 - 11/04/05 11:44 PM Occupancy sensor  
George Little  Offline
Member
Joined: Jan 2004
Posts: 1,489
Michigan USA
210.70(A)(1) Exception No.2 talks about an override capability and my question is- What gets overridden- the turning on or the turning off? And what does the overriding? duh


George Little

2017 / 2014 NEC & Related Books and Study Guides

#96113 - 11/05/05 04:21 AM Re: Occupancy sensor  
Tesla  Offline
Member
Joined: Jun 2004
Posts: 1,273
Sacramento, CA
The 1st exception is clear: it allows bedroom wall switches to control one or more suitable receptacles that will be subsequently used by the resident to heat up free standing lamps.

In the code, an outlet is taken to be a direct wiring of a light fixture -- in this instance -- whereas it is so common to have no overhead light fixture in the bedroom: all lights are to be lamps.

This style of lighting may include a more substantial space such as a living room.

The Second exception allows for occupancy sensors in lieu of traditional switches. Think of WattStoppers and its rivials. These can be dropped in directly to replace ordinary switches. They can also be wired in series with traditional switches.

These 'new' devices are what is addressed. Again, they are switching wall receptacles that are intended to heat up free standing or table lamps.



[This message has been edited by Tesla (edited 11-05-2005).]


Tesla

#96114 - 11/05/05 07:02 AM Re: Occupancy sensor  
iwire  Offline
Moderator
Joined: Jan 2003
Posts: 4,391
North Attleboro, MA USA
Quote
What gets overridden- the turning on or the turning off?


George I am glad you asked as that is something I have wondered.

Most of the wall switch motion sensors I have installed can only be overridden to the 'off' mode. To override them to 'on' usually means getting into the adjustment section.

Here is the exception George is asking about.

Quote
210.70(A)(1)Exception No. 2: Lighting outlets shall be permitted to be controlled by occupancy sensors that are (1) in addition to wall switches or (2) located at a customary wall switch location and equipped with a manual override that will allow the sensor to function as a wall switch.


I have a related question.

Quote
110.26(D) Illumination. Illumination shall be provided for all working spaces about service equipment, switchboards, panelboards, or motor control centers installed indoors. Additional lighting outlets shall not be required where the work space is illuminated by an adjacent light source or as permitted by 210.70(A)(1), Exception No. 1, for switched receptacles. In electrical equipment rooms, the illumination shall not be controlled by automatic means only.


Does this rule out a motion sensor even if it can be overridden?

Bob


Bob Badger
Construction & Maintenance Electrician
Massachusetts

#96115 - 11/05/05 09:13 AM Re: Occupancy sensor  
resqcapt19  Offline
Member
Joined: Nov 2000
Posts: 2,148
IL
Bob,
Quote
Does this rule out a motion sensor even if it can be overridden?

If it can be overridden, it is not "automatic only".
Don

[This message has been edited by resqcapt19 (edited 11-05-2005).]


Don(resqcapt19)

#96116 - 11/05/05 09:24 AM Re: Occupancy sensor  
iwire  Offline
Moderator
Joined: Jan 2003
Posts: 4,391
North Attleboro, MA USA
Don the question still remains which way must the override work?

Override it ON, OFF or both?

It seems self explanatory that in the Elec room you would want to override the light ON but it does not say that.

I think there may be a conflict with the energy codes with a ON override.

Bob


Bob Badger
Construction & Maintenance Electrician
Massachusetts

#96117 - 11/05/05 10:00 AM Re: Occupancy sensor  
Tiger  Offline
Member
Joined: May 2005
Posts: 706
Crystal Lake, IL USA
Leviton's Occupancy sensor that replaces a switch is Catalog No. 6768. (if anyone can provide a link).

It states in the catalog "Push-botton manual override allows controls to be used like standard ON/OFF switches;

manual-ON/Auto-OFF mode"

I read that as the unit overriding the ON.

Dave


#96118 - 11/05/05 11:02 AM Re: Occupancy sensor  
HLCbuild  Offline
Member
Joined: Dec 2004
Posts: 209
Herndon,Va USA
Seems to me if it is required to function as a wall switch, it must be able to turn on and off...just as a wall switch will do.


#96119 - 11/05/05 01:04 PM Re: Occupancy sensor  
gfretwell  Online Content


Member
Joined: Jul 2004
Posts: 9,123
Estero,Fl,usa
If it replaces the wall switch it is clear it must have both manual on and off capability. The question is with "in addition to..."
Basically is the M/D wired in series or parallel?
I think it is ultmately a design decision. I have about 20 in and out of the house so can argue both sides of that ;-)


Greg Fretwell

#96120 - 11/05/05 05:35 PM Re: Occupancy sensor  
HLCbuild  Offline
Member
Joined: Dec 2004
Posts: 209
Herndon,Va USA
I think it would have to be wired in parallel. If it was in series and the primary wall switch were in the off position it would not allow the motion switch to "function as a wall switch".


#96121 - 11/05/05 10:25 PM Re: Occupancy sensor  
Tesla  Offline
Member
Joined: Jun 2004
Posts: 1,273
Sacramento, CA
These switches -- WattStopper, etc. -- inregards to 210.70 (A) exception 2 are for habitable spaces.

In all my days, I've never installed one in an electrical or service room.

The energy conservation rules kick intelligence in at 100 square feet whenever it would not create a hazard.

If you're in the room, the automatic feature triggers it on...with a delay after your departure.

You can kill it anyway so as to permit viewing movies, TV, or sleeping.

The device logic always requires power ahead of its own switching. So the automatic switch is in series with the manual override built into the device.


Tesla


Member Spotlight
Admin
Admin
NY, USA
Posts: 3,458
Joined: October 2000
Show All Member Profiles 
Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.017s Queries: 14 (0.004s) Memory: 0.8115 MB (Peak: 0.9866 MB) Zlib enabled. Server Time: 2017-10-20 01:32:57 UTC