Guy is saying a licensed electrician installed service panel

[Sam Morris]

The secondary panel was 6" away from main panel with a 100 amp OCPD device installed in main service panel. The aka sub panel had a double tap at main lug with service going to outbuilding that had a 100 amp panel inside the building. I told the homeowner that there was NO disconnect for the service wires going to outbuilding (which was 100 yards away) and the "electrician" had doubled tapped on a lug that is rated for 1 wire only. I'm hoping this was a correct statement ??

[Jerry Peck]

(underlined all caps is my edit to keep terms consistent for clarity, not sure why two different terms were used for the same panel ... or were the two terms for DIFFERENT panels?)


The secondary panel was 6" away from main panel with a 100 amp OCPD device installed in main service panel. The SECONDARY panel had a double tap at main lug with service going to outbuilding that had a 100 amp panel inside the building.

Need more information: the 100 OCPD was the main service disconnect? Or was it a breaker which fed the secondary panel? It makes a difference.

First thing - there is that multiple tapping issue ... it is there regardless of what else is there.

Second thing - if ... IF ... if that 100 amp OCPD IS the main service disconnect and the bus is a feed-through bus (terminal lugs at top and at bottom) or has a sub-feed tap without OCP (is not a breaker), then the feeders to the secondary panel are required to be rated for at least 100 amp, the mains of the secondary panel are required to be rated for at least 100 amp, the feeders to the outbuilding panel are required to be rated for at least 100 amp, and the mains at that outbuilding panel are required to rated for at least 100 amp ... oh, and that entire service ... it is no more than 100 amp FOR EVERYTHING as not more than 100 amp is getting through that mains service disconnect.

Third thing - if ... IF ... if that 100 amp OCPD IS fed off the main service equipment panel bus (is a breaker in the service equipment panel) to the secondary panel and to the outbuilding panel, then the feeders to the secondary panel are required to be rated for at least 100 amp, the mains of the secondary panel are required to be rated for at least 100 amp, the feeders to the outbuilding panel are required to be rated for at least 100 amp, and the mains at that outbuilding panel are required to rated for at least 100 amp.

Regarding this part:

I told the homeowner that there was NO disconnect for the service wires going to outbuilding (which was 100 yards away) and the "electrician" had doubled tapped on a lug that is rated for 1 wire only. I'm hoping this was a correct statement ??

If the "second thing" above is correct, then the main service disconnect is the OCPD for the feeders going to the secondary panel and for the feeders going to the outbuilding panel.

If the "third thing" above is correct, then the OCPD in the service equipment panel which feeds the secondary panel is the OCPD for the feeders going to the secondary panel and the feeders going to the outbuilding panel.

As long as the feeders for both the secondary panel and the outbuilding panel, and the mains for both the secondary panel and the outbuilding panel, are all rated at least 100 amps, then it becomes a tap issue only ... presuming that the outbuilding panel is installed properly, has a 4-wire feeder, has a grounding electrode system, has less than six mains, etc.

[Sam Morris]

The secondary panel was 100 amp (the OCPD for secondary panel was installed in the main service panel, which was a 200 amp) The double taps were in the secondary panel. So its OK to have the 100 amp secondary panel OCPD in the main service panel and not inside the secondary panel itself (the only problem is the DOUBLE tap correct ? The secondary panel service wires coming into box were rated for 100 amp, at the double tap was the 100 amp with 200 amp (with 200 amp are lateral service wires going to outbuilding over 75 yards away. Thanks In Advance

[Jerry Peck]

The secondary panel was 100 amp (the OCPD for secondary panel was installed in the main service panel, which was a 200 amp) The double taps were in the secondary panel. So its OK to have the 100 amp secondary panel OCPD in the main service panel and not inside the secondary panel itself (the only problem is the DOUBLE tap correct ? The secondary panel service wires coming into box were rated for 100 amp, at the double tap was the 100 amp with 200 amp (with 200 amp are lateral service wires going to outbuilding over 75 yards away. Thanks In Advance

The easy way to think of it is that, in order to protect the conductors, the overcurrent device has to be located at the supply (line side) of the conductors. Service entrances conductors are permitted to be protected on the load side as service entrance conductors are located outside the structure (with an exception for a very limited length inside the structure), there are also exceptions for protection of outside tap conductors ... but basically think of it protecting the conductors at their supply (line) end.

The 200 amp feeders (underground laterals) to the outbuilding seem like overkill, except that at 75 yards (150 feet) the conductors were likely upsized to account for voltage drop for that distance.

[Brad Richter]

Am I mistaken or are those 100 amp conductors not full conductors inserted into the 100 amp breaker? May be an illusion but it looks like only one strand terminated on the breaker.

[Sam Morris]

Am I mistaken or are those 100 amp conductors not full conductors inserted into the 100 amp breaker? May be an illusion but it looks like only one strand terminated on the breaker.
Its 2 wires going in

[Brad Richter]

Its 2 wires going in
2 wires or 2 strands?

[Jerry Peck]

I just noticed something, something that I have mentioned before as I recall - see that yellow stripe on the neutral? What does the identification for those conductors say it is?

My recollection is that (I've forgotten the designation I found before) was rated only for use as service entrance conductor ONLY and was specifically stated as (maybe it was on the conductors, or maybe in the information I looked up) NOT being suitable for use inside a building.

If that is the case with that, then those are intended for installation by utility companies as use for underground service laterals TO the service equipment located on the exterior of the building ONLY, and not to continue into the building (not go through the building's exterior wall to a panel inside, and not to be used inside the building).

Just my recollection of that yellow stripe in the past - would need the markings on the conductor to know or check on it.

[jack davenport]

Maybe I missed it - BUT nobody has mentioned that bright green bond screw installed on the neutral bar in that secondary ( sub) panel............

[Jerry Peck]

Maybe I missed it - BUT nobody has mentioned that bright green bond screw installed on the neutral bar in that secondary ( sub) panel............

Because I can't tell from the photo that it is actually screwed into place in the back of the enclosure.

[John Kogel]

Because I can't tell from the photo that it is actually screwed into place in the back of the enclosure.Nice quick comeback, JP.
But a licensed electrician would pull the screw to prevent a goof from tightening it.

All further proof of a pack of lies surrounding that amateur installation.:(

[Jerry Peck]

But a licensed electrician would pull the screw to prevent a goof from tightening it.

All further proof of a pack of lies surrounding that amateur installation.:(

I disagree.

I rarely saw the screws removed by the electricians on new houses.

One more 10 second action which was not needed, so way do it ... seemed to be the reasoning.

I definitely WOULD NOT call it a amateur installation based on the ground bond screw having been left in place - that is kind of like saying it is an amateur installation because there is a multiple tap ... and how many times have we seen electricians make multiple taps on new installations - a bunch.

[jack davenport]

My money is on that screw being installed completely. But will never know unless the OP chimes back in.................

[Sam Morris]

My money is on that screw being installed completely. But will never know unless the OP chimes back in.................
It looks like the bonding screw was not removed (good catch)

[Rollie Meyers]

I just noticed something, something that I have mentioned before as I recall - see that yellow stripe on the neutral? What does the identification for those conductors say it is?

My recollection is that (I've forgotten the designation I found before) was rated only for use as service entrance conductor ONLY and was specifically stated as (maybe it was on the conductors, or maybe in the information I looked up) NOT being suitable for use inside a building.

If that is the case with that, then those are intended for installation by utility companies as use for underground service laterals TO the service equipment located on the exterior of the building ONLY, and not to continue into the building (not go through the building's exterior wall to a panel inside, and not to be used inside the building).

Just my recollection of that yellow stripe in the past - would need the markings on the conductor to know or check on it.

It's URD cable, & is not allowed in a building.

There is a whole lot of things wrong with that install, another question to ask is what is right with it.

[Jerry Peck]

It's URD cable, & is not allowed in a building.

Thank you for the memory jog, Rollie.

When HIs see that yellow stripe, they need to read along the conductor identification, I believe it says that in the identification markings.

If it comes up out of the ground and terminates in service equipment mounted on the exterior - no problem with it there, but ... if it continues "into or through the wall" ... then it is not allowed.