225 amp spliced to 100 amp service - crazy?

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anclarizio

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Just curious if anyone else has ever seen this? I manage the facilities at several camps and was having an issue with breaker tripping in one of the buildings. Called my electrician
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and we discovered this box between 2 buildings. It is 225 amp wire coming from a main outdoor panel box with 1 225 amp breaker and then 100 amp wire spliced going to 2 different building with 100 amp panels. He was pretty freaked out by this just wondering if this was done regularly back in the day? This mess would have been installed in the 1980s I think.
 
So you have wire with 225A capacity fed by a 225A breaker, which splits to two 100A wires which then supply 100A breakers?

If so, this means that you have 'taps' protected by the breakers at the load end. Not knowing anything else about the installation, this aspect sounds correct.

There are specific rules for the allowed break sizes and tap lengths.

Jon
 
winnie said:
So you have wire with 225A capacity fed by a 225A breaker, which splits to two 100A wires which then supply 100A breakers?

If so, this means that you have 'taps' protected by the breakers at the load end. Not knowing anything else about the installation, this aspect sounds correct.

There are specific rules for the allowed break sizes and tap lengths.

Jon
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The 100 amp wires from this box run underground to 2 separate buildings and 100 amp panels. Electrician says this in dangerous and instead of splices this box should have 100 amp disconnects in it for each building.
 
It appears that the outside taps of unlimited length was added in the 1999 code, so not likely compliant when installed, but likely compliant now.
 
Okay he was leading me to believe this was a dangerous and illegal installation because of the 225 amp load on 100 amp wires but when I just read the rule it makes sense because of the 100amp breakers at the load.
As far as the breaker tripping -when taking readings at the panel he is getting 25 volts on the neutral even when the main switch is off. He is also getting low voltage on the conduit coming into the building. He said this would cause a breaker to trip but not sure why it's just 1 breaker.
 
ptonsparky said:
Very common installation.
I would be looking more closely at the breaker and it's connections. Line, load and internal.
Detail we should know first, Is the breaker actually tripping on overload or fault?
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I think fault but I would have to ask electrician.
 
At this point you should suggest that your electrician join to get help troubleshooting. Trying to provide indirect support is a never ending story of missed details.
 
letgomywago said:
What were the tap rules before then? Just 25ft and 10ft?
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don_resqcapt19 said:
It appears that the outside taps of unlimited length was added in the 1999 code, so not likely compliant when installed, but likely compliant now.
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I don’t know when it changed, but it was very common in rural areas here. It really did not make much sense to allow #6 to a building with no overcurrent protection ahead of it, vs one with 200 amp, not allowed.
 
anclarizio said:
The 100 amp wires from this box run underground to 2 separate buildings and 100 amp panels. Electrician says this in dangerous and instead of splices this box should have 100 amp disconnects in it for each building.
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As mentioned above, this installation is likely safe and code compliant because it's protected by breakers at the far end.

While it is hypothetically possible that a fault could occur upstream of the breakers and overload & overheat these feeders, the risk of that happening is low because they're underground. And the risk of them setting anything on fire if that does happen is also low because they're underground.

A critical inspection is never a bad idea, but this doesn't sound like something to lose sleep over.
 
don_resqcapt19 said:
It appears that the outside taps of unlimited length was added in the 1999 code, so not likely compliant when installed, but likely compliant now.
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I have a copy of the 1996 NEC, and I think I see a section describing outside feeder taps of unlimited length. Section 240-21 (m), Outside Feeder Taps. It allows outdoor conductors suitably protected from physical damage to be installed with no overcurrent protection at their supply end, provided a single set of fuses or breakers protects them at the other end.
The margin has markings indicating revisions from a previous code version, so it must have already been in whatever revision came before 1996.
 
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