1997 Manufactured home. Meter base is a few yards from the home. Under the meter is a 200amp breaker disconnect along with a couple other breakers that run the well, an outlet located at the meter base and one other unmarked breaker.
On each side of the base are two Square D disconnect panels with a 100 amp breaker in each. One goes to the garage and one to the home.
Inside both the home and the garage is a 100 amp panels but both are wired like main panels with bonded neutral and ground busbars. I am a little confused in this entire configuration so I need a little help with it please.
There is a sub-sub panel in the home that is also has bonded busbars so I’m calling it out to be evaluated, but I’m not sure if the outside panels (disconnects would be considered the main panel and all other panels are subpanels???)
To me it looks like a mess, (but that’s not a very professional assesment)
1st pic is one of the two 100a disconnects. Pic 2 shows the 200a main disconnect under the meter and the two boxes on either side. Pic 3 is the panel in the garage.
There are instances where a “sub-panel” in a detached structure can have the neutrals and grounds bonded and that sub “acts” like a main panel.
A mobile home with a pedestal service is a classic example.
I can and will agree that there are exceptions, but in all the manufactured homes I have inspected I have never seen a situation where the description that Kevin posted would be correct.
I do agree with the pedestal comment but personally I have only seen these in RV parks not perminently site manufactured home sites.
First off, I need to clarify a mistake I made. I meant to say “modular” home, not “mobile”.
OK, it was (is) very common to run just a three conductor feeder to a detached structure. As long as there are no other metallic paths between structures this is perfectly legal and safe. In any situation, a detached structure fed by a feeder (as opposed to just a branch circuit) DOES require a ground rod(s).
There is talk that this {250.32(B)(2)} will be eliminated from the 2008 code, but there are thousands of legal installations like this out there.
For an NEC reference:
250.32(B) Grounded Systems For a grounded system at the separate building or structure, the connection to the grounding electrode and grounding or bonding of equipment, structures, or frames required to be grounded or bonded shall comply with either 250.32(B)(1) or (B)(2).
**
(1) Equipment Grounding Conductor* An equipment grounding conductor as described in 250.118 shall be run with the supply conductors and connected to the building or structure disconnecting means and to the grounding electrode(s). The equipment grounding conductor shall be used for grounding or bonding of equipment, structures, or frames required to be grounded or bonded. The equipment grounding conductor shall be sized in accordance with 250.122. Any installed grounded conductor shall not be connected to the equipment grounding conductor or to the grounding electrode(s).
(2) Grounded Conductor Where (1) an equipment grounding conductor is not run with the supply to the building or structure, (2) there are no continuous metallic paths bonded to the grounding system in each building or structure involved, and (3) ground-fault protection of equipment has not been installed on the supply side of the feeder(s), the grounded conductor run with the supply to the building or structure shall be connected to the building or structure disconnecting means and to the grounding electrode(s) and shall be used for grounding or bonding of equipment, structures, or frames required to be grounded or bonded. The size of the grounded conductor shall not be smaller than the larger of either of the following:
(1) That required by 220.61
(2) That required by 250.122*
lol…fine as speedy says until indeed 2008 NEC is adopted, then in new construction the allowances of 250.32(B)(2) will VANISH…so it will linger on in older or pre-2008 NEC worlds…BUT our childrens children will not even know 250.32(B)(2) even existed someday…;)…I HOPE
250.32(B)(2) was the last of the WWII “copper saving” rules that were in the code (allowing current in load side grounds). As Phil Simmonds said in his 1996 proposal to remove the exception for dryers and ranges “the war is over”.
