Pete,
I would say we need to continue to call it out. Unless you know of some way to absolutely, positively prove that there is no other metallic pathway, defer to the electrician. Let them make the call on their letterhead.
Ok…Peter we are getting into some TECHINCAL stuff here for Home Inspectors…let me try to explain because I want you to be clear on this…as well as anyone reading it because as electricians WE know this stuff my heart…but we need to break it down for clarity.
[size=2]408.40 Grounding of Panelboards
Panelboard cabinets and panelboard frames, if of metal, shall be in physical contact with
each other and shall be grounded. Where the panelboard is used with nonmetallic
raceway or cable or where separate grounding conductors are provided, a terminal bar for
the grounding conductors shall be secured inside the cabinet. The terminal bar shall be
bonded to the cabinet and panelboard frame, if of metal; otherwise it shall be connected
to the grounding conductor that is run with the conductors feeding the panelboard.
Ok…read this portion…
A separate equipment grounding conductor terminal bar must be installed and bonded
to the panelboard for the termination of feeder and branch-circuit equipment grounding
conductors. Where installed within service equipment, this terminal is bonded to the
neutral terminal bar. Any other connection between the equipment grounding terminal
bar and the neutral bar, other than allowed in 250.32, is not permitted. If this
downstream connection occurs, current in the neutral or grounded conductor would
take parallel paths through the equipment grounding conductors (the raceway, the
building structure, or earth, for example) back to the service equipment. Normal load
currents on the equipment grounding conductors could create a shock hazard. Exposed
metal parts of equipment could have a potential difference of several volts created by
the load current on the grounding conductors. Another safety hazard created by this
effect, where subpanels are used, is arcing or loose connections at connectors and
raceway fittings, creating a potential fire hazard.
Hope this explains it better…[/size]
One could have a 40 ckt panel with just 6 overcurrent devices and it would be compliant. It is not the available spaces in a panel, it is the number of overcurrent devices. We install and inspect for what is installed, not “what if”.
See now this I never knew. It is interpreted around here like I explained. I have done that for years. I never get bigger than a 6/12 panel if no main will be used.
Thanks for the clarification Pierre.
Pierre and Pete
Care should be taken when using the six disconnect rule in a remote building such as a detached garage.
225 clearly states that there must be a disconnect and that this disconnect is to be suitable as service equipment.
To the best of my knowledge there is not a manufacture of main lug panels that list their panels suitable as service equipment using the six disconnect rule. They require that a main be installed.
lets throw some confussion in the mix…
What if they are “Sub-Feeding” a pool panel with only 6 OCPD breaker in it…it is not passing thru anything and all exterior/exposed mountings…
So…is a main breaker needed or a MLO only…
Pete
You are welcome>
Mike
You may be on to something there… Now you have got me wondering about that for detached buildings…I will have to do some research.
This is a good reason why I visit these different sites, always something to learn.
Thanks Mike
Well let’s look at what is said in 225
I think that there would be no argument about what a building is but, what is a structure?
If this panel is mounted on something that is built I would say that a main would be required.
Ahhh… we all can agree to that…now what if the so called sub-panel is a pool control system which is designed for pool controls…lol…has main lug only…but only for pool equipment…then is it really a subpanel or pool equipment panel…then is a main needed…lol…p.s. i know what 225 says…i an trying to confuse it a bit…lol
lol…Ok…let me see if can clarify this a bit…lol
NEC 225.31 says as you stated mike :
However…lets examine 225.33 a bit…
AHhh…so are you saying 225.33 does not apply to 225.31 and the ability to have not more than 6 switches or six circuit breakers mounted in a single enclosure?
Lets look at NEC 225.30 now…just for fun…
Ok…we are talking about a single feeder to a single sub-panel…yep…225.30 applies to this application.
BTW…great discussion…my pool reference was to inteli panels that are control centers as well and they ONLY come as main lug only panels with a rating up to 125A…since they are dedicated for pool systems only…are they SUB PANELS…or pool control panels ?..interesting stuff my fellow electricians…;)[/size][/FONT][/size][/FONT]
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In this case I would go to 680.12 Maintenance Disconnecting Means. One or more means to disconnect all ungrounded conductors shall be provided for all utilization equipment other than lighting. Each means shall be readily accessible and within sight from its equipment.
Now this disconnecting means will need something to mount on so I am back to 225 and 250.32
How am I doing???
Do I get another one to them little square things?
ok…no greenie just yet ( but you know I will give you one anyway )…so this control panel and listed as such with an 8 circuit main lug assembly must have an " Disconnect " ahead of it at the control panel location…is that what you are saying…gotta ask before I give our greenies…lol
And if you rule this as a " sub-panel ",…man I hate that term…but anyway if you rule it as a sub…are you saying ( taking you back to memories of 2005 now )…the 6 throw rule does not apply to this enclosure?
Remember now…if it is a inteli-panel…would not have anything inside what so ever refering to as service equipment…which it is not anyway.
man I can’t wait all day for replies…lol…
This question was posted at a IAEI meeting and code panel responded with this:
- I have a detached garage with a panel in that accessory building that has 12 circuits available in that panel. I am installing only 6 - 120 volt single pole branch circuits in that panel in that garage. Do I meet the requirements of the 6-disconnect rule because I only have 6 sweeps of the hand installed? (service or sub-panel)
Panel Response: Yes, assuming the panel is served by a feeder with overcurrent protection, then mains are not required in this panel. NEC 408.36(A) Exception 1
Hang in there…I have a method to my madness…
OK…the reason I gave the senerios is because of a proposal I am working on…but I wont bore you with it…
My opinion is that YES, each seperate structure does require a disconnect and it can be governed under the 6 disconnect rule…but does not remove the requirements of the disconnects within 225.32
It is not a service and would not be considered as such…
Now granted 408.36(A)(1) says that no main is required IF the OCPD feeding the said MLO panel does not exceed the panels rating…yada…yada…yada…basically here is my take on this…
Nothing will remove the requirement of 225.32 on a “outside” detached structure…it needs to have disconnection means…the 6 breakers would comply…but they need to be present…the 408.36(A)(1) is applying to panelboards in general…we can’t delute the requirements of 225.32…this is why if the panel is not detached ( within the dwellling so to speak )…it can be a MLO as long as the OCPD feeding this panel does not exceed the panels ratings…
Good stuff…man I am glad someone bought up that topic
If this is a control panel that is listed as part of the pool equipment it would fall under the rules of 680.12 and a disconnect would be required for the control panel.
If this panel is remote from the building that it is fed from the six disconnect rule wouldn’t matter as there has to be a disconnect that is rated as service equipment installed at the remote building or structure.
I am not quite sure what you mean by inteli-panel. I think of an inteli-panel as an electronic control panel that does not have overcurrent protection. If this panel has overcurrent or not if it is part of the listed pool equipment it is required to have a disconnect ahead of it and this required service disconnect then would have to comply with 225.30 through 39 and 250.32
I feel one of them greenies coming on lol
OH…BTW…is the inteli-panel control center at a pool a power panel or L & A panel anyway…lol…only supplying utilization equipment for the pool…BUT does have line to neutral loads exceeding 10%…
interesting stuff…
lololol…greenie hungry are ya Mike…lol
But what if not listed as part of ANY pool equipment…yet designed to work WITH pool equipment…lol
actually the inteli-panels I see mike have both a main lug 8 ckt buss on the bottom and above it has relays that control lights in the pools, spa pumps and so on…kinda intergrated together…
The manuals for these things I believe state the OCPD needs to be in the dwelling…lol…you would think if that is the case the installation manuals for the control center would say about a disconnect ahead of it at the pump/panel installation point…
here you go mike…these are the ones I am refering too
http://www.aqua-pool-warehouse.com/Catalogs/catTimersNControls/Enclosure-Kits.asp