Inspector-"I want to see some load calcs"

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sfav8r

Senior Member
We have a 6 unit building where the owners (6 unit TIC bldg) want to replace the 6 sub panels and 1 house panel because the existing equipment is FP. These are approximately 600sq ft units with the typical 2 outlets per room for this vintage bldg. Some have dishwasher/disposals. None have laundry circuits, 2 appliance circuits, etc.

The current configuration is overhead feed to a disconnect which feeds a 3-meter gutter and a 4-meter gutter. Each meter drops down to a sub panel.

We recommended that the entire service be changed and upgraded to 300a and we also gave an alternate estimate to replace just the sub panels and leave the existing 175a disconnect. The association opted to do the panels now and build a reserve account to upgrade the service at the end of next year. We had the inspector look at the job prior to starting because of some clearance concerns. At that time he said "you're going to need to upgrade the service." We argued that we were not doing anything to the service and were just changing sub panels since everything we were doing is after the disconnect. He said "if you can't show me load calcs showing that the service is adaquate then you can' change just the sub panels because you are "essentially" changing the service.

So here are my specific questions:

I believe that I am 100% correct that this is NOT a service upgrade in any way as far as the NEC is concerned.

I believe that it would be best to upgrade the service, but that if the client cannot afford to do it all at once it is reasonable to get rid of the FP panels now and upgrade the service later.

I believe that the inspector should NOT require any load calcs for the changing of the panels only. And, if he did want to see calc, it should be only on what is actually installed at this time and not the 2 appliance circuits per unit, laundry, etc, that would be required on a new service.

Any thouoghts?
 

480sparky

Senior Member
Location
Iowegia
There is no such thing as a 'service upgrade' as far as the NEC is concerned.

The NEC only addresses the work you are going to do, and you're installing a new service. New services require load calcs.
 

480sparky

Senior Member
Location
Iowegia
I disagree Replacing sub panel is not changing a service.
The point is, will the newly installed equipment be able to handle the load impressed on it?

If you were asked to replace a #12 wire that you knew had 50amps on it, would you just pull the old 12 out and put new 12 back in just because you're not 'updating' the circuit with new overcurrent devices, new raceways, etc?
 

SEO

Senior Member
Location
Michigan
If you were asked to replace a #12 wire that you knew had 50amps on it, would you just pull the old 12 out and put new 12 back in just because you're not 'updating' the circuit with new overcurrent devices, new raceways, etc?
Good analogy 480sparky.
 

mikeames

Senior Member
Location
Germantown MD
Occupation
Teacher - Master Electrician - 2017 NEC
I disagree it is not a good analogy because one scenario is a great immediate danger and one is not.
There is a huge difference between a #12 with 50 amps on it and an existing service with properly sized OCPD. OCPDs are designed to interrupt power if the load becomes too great. As far as the NEC is concerned everything is acceptable. The service will be upgraded in the near future but as of now I would feel it is safe, unlike the 50 amps on a #12.
 

resistance

Senior Member
Location
WA
The point is, will the newly installed equipment be able to handle the load impressed on it?
I agree that a DLC can be requested---yet the inspector cannot require them to upgrade the service--without knowing the load cals.. I've never heard of inspector asking for DLC's for a panel change. I say, "Bravo!!!!" I wish they would start making DLC's mandatory [specific to the project]!! This would force us to utilize the skills we worked so hard to gain!! ...............May even create some work for electrical contractors!
 

mivey

Senior Member
If my 200 amp panel serves as my disconnect, And I replace two 125 amp subpanels, I am now required to change the service?:confused:
 

mikeames

Senior Member
Location
Germantown MD
Occupation
Teacher - Master Electrician - 2017 NEC
No but you have to do a load calc to be sure. :grin:

According to the OP nothing has changed. They just want to change the equipment because its FP. granted the 175 is too small and circuits shoul dbe added but thats not part of this discussion. The issues is a replacement. The Op did not mention adding circuits / loads. If I am hired to do a 200 amp service upgrade on a 70 years old house I am not going to rewire the entire house to bring it up to current code.
 
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resistance

Senior Member
Location
WA
No but you have to do a load calc to be sure. :grin:
Doing a DLC doesn't seem unreasonable to me!! Maybe if we start doing them, we will know how to do them!


Yet, I do find it unreasonable for an inspector to request a service upgrade, if he or she has no idea about the load requirements!!
 

mikeames

Senior Member
Location
Germantown MD
Occupation
Teacher - Master Electrician - 2017 NEC
Doing a DLC doesn't seem unreasonable to me!! Maybe if we start doing them, we will know how to do them!


Yet, I do find it unreasonable for an inspector to request a service upgrade, if he or she has no idea about the load requirements!!
I dont think its unreasonable either, but why if no loads have changed??? Yea the service is undersized for todays standards but nothing has change and many many buildings today do not meet current code, but they are grandfathered in. If something with the service was being change then I would agree that a load calc should be done and the service should be brought up to current code, but this application is talking about sub panels.

Also why do we need to do more of them to know how to do them. I know how to do them and I have only done a few. I think they are straight forward.
 

resistance

Senior Member
Location
WA
I dont think its unreasonable either, but why if no loads have changed??? Yea the service is undersized for todays standards but nothing has change and many many buildings today do not meet current code, but they are grandfathered in. If something with the service was being change then I would agree that a load calc should be done and the service should be brought up to current code, but this application is talking about sub panels.

Also why do we need to do more of them to know how to do them. I know how to do them and I have only done a few. I think they are straight forward.
Why should we do (practice;study) more of anything that we enjoy (or may not enjoy) doing: 1. It makes us better people--more valuable to self and others! 2. For some, it's in their job description. 3. For many other reasons--too many to list

How many us can truly say we can work an electrical math problem without referencing a mike Holt, or whatever book--if we have not done the problem on a regular basis? I don't know about you, but I tend to forget things that aren't introduced on a regular basis.
 
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We have a 6 unit building where the owners (6 unit TIC bldg) want to replace the 6 sub panels and 1 house panel because the existing equipment is FP. These are approximately 600sq ft units with the typical 2 outlets per room for this vintage bldg. Some have dishwasher/disposals. None have laundry circuits, 2 appliance circuits, etc.

The current configuration is overhead feed to a disconnect which feeds a 3-meter gutter and a 4-meter gutter. Each meter drops down to a sub panel.

We recommended that the entire service be changed and upgraded to 300a and we also gave an alternate estimate to replace just the sub panels and leave the existing 175a disconnect. The association opted to do the panels now and build a reserve account to upgrade the service at the end of next year. We had the inspector look at the job prior to starting because of some clearance concerns. At that time he said "you're going to need to upgrade the service." We argued that we were not doing anything to the service and were just changing sub panels since everything we were doing is after the disconnect. He said "if you can't show me load calcs showing that the service is adaquate then you can' change just the sub panels because you are "essentially" changing the service.

So here are my specific questions:

I believe that I am 100% correct that this is NOT a service upgrade in any way as far as the NEC is concerned.

I believe that it would be best to upgrade the service, but that if the client cannot afford to do it all at once it is reasonable to get rid of the FP panels now and upgrade the service later.

I believe that the inspector should NOT require any load calcs for the changing of the panels only. And, if he did want to see calc, it should be only on what is actually installed at this time and not the 2 appliance circuits per unit, laundry, etc, that would be required on a new service.

Any thouoghts?
Yes.

I would ask him to show me where IS it required that it should be part of the inspection. Not that load calculations are required or not by the NEC, but that that it should be part of the inspectable material. He can have an entire set of engineering drawings for an installation and find not a SINGLE load calculation within.
 

iwire

Moderator
Staff member
Location
Massachusetts
I would ask him to show me where IS it required that it should be part of the inspection. Not that load calculations are required or not by the NEC, but that that it should be part of the inspectable material.
There is nothing in the NEC about what is and what is not required for inspection. Those issues are handled by each area. They can certainly request to see load calculations. The fact that in your area you have not had this request has nothing at all to do with what another area may request.

He can have an entire set of engineering drawings for an installation and find not a SINGLE load calculation within.
Very true, that can and does happen. I assume that when they see an engineering stamp on the drawings they take that as a sign the job has been designed correctly.

But many times there are no 'engineered' drawings at all, just a permit application with a job description. In that case it would seem prudent of an inspector to ask what the calculated load is.
 

mpd

Senior Member
I believe the inspector is permitted to ask for load calculations, but in this situation if nothing has changed, there is no evidence of additional loads or overheating that could make the existing not compliant i think the load calc. should wait until the entire service is done.

but with that said, what would the inspector do if the work did not get done at all, if he thinks the service is unsafe he must issue a notice of violation and demand a load calculation.
 

Jim W in Tampa

Senior Member
Location
Tampa Florida
While i agree that all your doing is replaceing panels and not changing loads i must side with inspector. He sees what looks like an overloaded install and does not want his name on it.
Give him the load calc as building is now. If that passes then fine. Is what is there now been inspected ? Or just the results of many years of unpermited work ?
 
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