4/0 Service spliced down to 1/0 in panel before breaker

H

HiSpeed68

Member
Location
florida
Occupation
Home Inspector
Hey everyone, I'm a Florida home inspector who researches as much as possible before just asking for an answer. Now I've got an issue on a panel I can't find a definitive answer to. Florida owner had panel replaced after flooding and apparently fired the first electrician. There are multiple other issues I called out but I want to focus on the splicing of the service entrance between the switch and the main in the pics.

The service entrance is 4/0 copper to the main panel but it's not connected to the 200a breaker. Instead, it's has a compression splice to 1/0 THWN-2 copper that runs to a generator switch and the 1/0 copper returns back to the 200a breaker. The owner says another electrician says the splice is ok but the amperage for 1/0 is only 175a which doesn't match the 4/0 rating or the 200a breaker.

Is there something in the NEC I'm not interpreting or don't know how to interpret correctly? I've researched 240.4 with no success but 310.12(A) leads me to believe it may be acceptable with the 83% rule being applied. I'll leave it at that and hopefully get some guidance/ help interpreting. Thanks for any help and stay safe.
 

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#1/0 copper is typcially a 150 amp conductor. With the 83% rule it can be used at 175 amps as you've stated. With the 83% rule #2/0 copper is the minimum size for 200 amps. The conductors to the switch need to be in a raceway or cable.
 
infinity said:
#1/0 copper is typcially a 150 amp conductor. With the 83% rule it can be used at 175 amps as you've stated. With the 83% rule #2/0 copper is the minimum size for 200 amps. The conductors to the switch need to be in a raceway or cable.
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Thanks! I didn’t think I was off on this one! I was using the amperage chart in the NEC but checking the manufacturer’s site it said max was 170a. I did call out the conduit. There’s a lot more going on and the owner is trying to cheap out on getting it done right.
Thanks again.
 
Quick question, is there a disconnect outside or just a meter. You mentioned service entrance conductors.

If so the service conductors are passing thru the panel and the feeder is returning to the panel via the transfer switch which would be the service disconnect.

Poor home owner if they paid someone.
 
Pretty good chance that transfer switch not suitable for use as service equipment either. Ignoring other aspects, the service conductors hit that switch first - it needs to be suitable for use as service equipment. I have never seen a manual transfer switch that is.

My suggestion for this one is get an interlock kit for that panel and put back fed generator breaker and hold down in the panel and get rid of that mess involving that transfer switch.
 
As a home inspector, I would make a general observation to the effect that “There are multiple issues/NEC violations with the wiring of the service, including (but not limited to) improper raceway installation and wire sizing. This is potentially unsafe and needs a thorough investigation by a licensed electrical contractor.” I would not offer specifics nor suggest remedies.

Just my opinion.
 
Great photo thanks for sharing, seems like generator installs often have issues but this takes the cake.
The service entrance conductors cant be in the same non-raceway as the feeder. :ROFLMAO:
The manual transfer switch does not appear to be 200 Amps< the last one I saw that was a manual 200A was the size of a load-center.
There is no sign of a grounding electrode system.
If an inspector here saw that they would have the POCO immediately pull the meter and not allow it to be energized until its inspected.
 
infinity said:
There is no way a licensed electrician did this job and it was inspected. The generator wires appear to be stubbed into the wall without any raceway. Plastic loom is not a substitute for a listed raceway.
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Agreed LOL. There’s much more trust me. That’s why I said focus on the splicing. Is there anything that can be interpreted to make this acceptable with such an undersized wire?
 
Tulsa Electrician said:
Quick question, is there a disconnect outside or just a meter. You mentioned service entrance conductors.

If so the service conductors are passing thru the panel and the feeder is returning to the panel via the transfer switch which would be the service disconnect.

Poor home owner if they paid someone
Tulsa Electrician said:
Quick question, is there a disconnect outside or just a meter. You mentioned service entrance conductors.

If so the service conductors are passing thru the panel and the feeder is returning to the panel via the transfer switch which would be the service disconnect.

Poor home owner if they paid someone.
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only the meter is outside. Much wrong for sure that’s why I asked to focus on the splicing. Is there any interpretation where the splice is correct?
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Tulsa Electrician said:
Quick question, is there a disconnect outside or just a meter. You mentioned service entrance conductors.

If so the service conductors are passing thru the panel and the feeder is returning to the panel via the transfer switch which would be the service disconnect.

Poor home owner if they paid someone
Tulsa Electrician said:
Quick question, is there a disconnect outside or just a meter. You mentioned service entrance conductors.

If so the service conductors are passing thru the panel and the feeder is returning to the panel via the transfer switch which would be the service disconnect.

Poor home owner if they paid someone.
Click to expand...
only the meter is outside. Much wrong for sure that’s why I asked to focus on the splicing. Is there any interpretation where the splice is corrsct
kwired said:
Pretty good chance that transfer switch not suitable for use as service equipment either. Ignoring other aspects, the service conductors hit that switch first - it needs to be suitable for use as service equipment. I have never seen a manual transfer switch that is.

My suggestion for this one is get an interlock kit for that panel and put back fed generator breaker and hold down in the panel and get rid of that mess involving that transfer switch.
Click to expand...
Absolutley correct! It’s only rated for 100A as well and much much more. Is there any interpretation where the splice is correct? Thanks
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retirede said:
As a home inspector, I would make a general observation to the effect that “There are multiple issues/NEC violations with the wiring of the service, including (but not limited to) improper raceway installation and wire sizing. This is potentially unsafe and needs a thorough investigation by a licensed electrical contractor.” I would not offer specifics nor suggest remedies.

Just my opinion.
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Oh I get it but this owner has used me a few times and I know he’s the one trying to do the work without telling me directly!! I just want to know about the splicing and cannot be interpreted in any way to be correct? Is there anywhere in the NEC that does or doesn’t allow this downsizing?
 
tortuga said:
Great photo thanks for sharing, seems like generator installs often have issues but this takes the cake.
The service entrance conductors cant be in the same non-raceway as the feeder. :ROFLMAO:
The manual transfer switch does not appear to be 200 Amps< the last one I saw that was a manual 200A was the size of a load-center.
There is no sign of a grounding electrode system.
If an inspector here saw that they would have the POCO immediately pull the meter and not allow it to be energized until its inspected.
Click to expand...
 
Tortuga,
Thanks, definitely a mess and spot on about the size of the switch! It’s only 100A! And for the record, I did miss the doubling up in same raceway! I’ve read that before and now I have a first hand example to lock it in my brain! Thanks for that education.

LMAO, electricians are just like home inspectors though… ask for a specific answer with a picture and we all get squirrelled and give a full evaluation of the pic instead of answering the main question. Don’t get me wrong Tortuga, I appreciate the help on this one but is there any interpretation in the NEC the splicing is allowed in this manner? Thanks again
 
HiSpeed said:
Is there anywhere in the NEC that does or doesn’t allow this downsizing?
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No it's not permitted to use a #1/0 conductor for 200 amps in this application. As Retired said state what you see and walk away, this is not a code inspection and likely outside of your SOP to perform one with specific violations. And as far as helping this client out there are so many violations with this installation anything other than a thorough inspection and corrections by a licensed electrician is putting your client in danger. You're not helping him if he actually tries to fix this mess himself based on your observations.
 
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