I just inspected a condominium. The utility company meter was outside as was the disconnect (adjacent to the meter). The panel inside seemingly serves as the main service panel (and the sole panel) but there is no main service disconnect in the panel box (as it is outside) and the panel is bonded as a sub-panel given the neutrals and grounds were totally separate. I am assuming this is a sub-panel. Can I also assume that whenever the main service disconnect resides outsides of the electrical panel then that panel will be a sub-panel?
NEVER assume anything when it comes to electrical. You must verify everything!
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If I remember correctly @rmeier2 described a situation whereas that is not always the case. He may drop in and add some clarity.
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Some usage of correct terminology would help. The disconnect outside would be the service where the neutral and ground bond would be installed. Any panel downstream would be a distribution panel feed by 4 wires and have neutrals and grounds separated.
A distribution panel on or in the same building as the service does not require a main breaker.
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Thank you. With you AND … what is the fourth wire for? For sure two hots and a ground. The fourth?
Will there always be a fourth when the disconnect is not present in the inside panel box?
Next question … is it the responsibility of the inspector to inspect proper bonding of the external disconnect? And in the report literally treat the two boxes as main service panel and sub-panel?
Thanks in advance for helping me here.
Bob Lam
Bob Lam Solutions
(703) 201-2121
Sub panels may or may not have a disconnect. Anything downstream from the main panel in the same structure should have grounds and neutrals isolated (keep in mind “panel” could be as simple as a disconnect switch which is sounds like it is in your case). Four wires incoming to the sub = 2 hots, 1 neutral, 1 ground.
Is it the inspector’s job to (fill in the blank)??? Yes, if it’s in the SOPs and you don’t state otherwise. No, if it’s not in the SOPs. I report if a system is grounded from the panel but I don’t go verify all paths to earth as they are typically underground or otherwise hidden. Remember you are only there to determine if things are “performing as intended.” Don’t get too caught up scrutinizing the design. It’s a long and winding road with changes at every curve (code cycle) that you are unlikely to be able to keep track of… nor are you supposed to be or being paid to do.
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I would just add that, in my opinion, you are also there to identify issues that may prevent proper performance moving forward. For instance, undersized conductors may be performing well at the time of the inspection, but may get overloaded by a new occupant.
It’s important to know some basics about how the electric system should be set up. Based on the OP’s questions and terminology, my best recommendation would be to get further training.
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If the distribution panel has a main has nothing to due with the number of wires feeding it. It would simply be a redundant switch.
The 4th wire is a grounding conductor and allows the neutral and grounding to be separated at the distribution panel. A rigid metallic conduit can qualify as the 4th conductor if continuous between enclosures.
Older codes allowed distribution panels in detached buildings from the service to be fed with 3 wires. The neutral was bonded to ground like a service.
With the 2020 NEC for dwellings an emergency disconnect is required on the outside of the house. This disconnect is not required to be the service disconnect so it is possible that on the load side of the EM disconnect you may still find only 3 conductors with the fourth conductor (the EGC) originating further downstream at the service.
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Thank you
Bob Lam
Bob Lam Solutions
(703) 201-2121
To put it simply…No. A home inspector is doing a visual inspection of the panel. If all conductors appear secured in their termination, then good. Inspectors do not determine the adequacy of bonding or trace circuits. AND inspectors do not poke around, probe or pull on anything in the panel.
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We see this often in Florida, an exterior electrical disconnect panel with the interior panel wired as a main panel. It is also very rare when you are doing condominium inspections that you will be given access to the main electrical shut-off which is usually located in a utility room on the floor of the condominium unit.
Are you saying that the service disconnect is on the exterior but the interior panel is not wired as a sub-panel?
Frank, thanks you sir.
Bob Lam
Bob Lam Solutions
(703) 201-2121
Disconnect on the exterior. Interior panel bonded as a sun-panel, not main panel.
Bob Lam
Bob Lam Solutions
(703) 201-2121
How does that pass inspection?
Let’s see some pic’s.
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Why would it not pass inspection? Exterior is treated as main panel and interior as sub-panel.
Regards,
Bob Lam
Bob Lam Solutions
BobLamSr@gmail.com
(703) 201-2121
My original quote was of Frank’s post where he stated that the interior panel was wired as a main with an exterior service disconnect.