Jump to content

Amperage rating


Recommended Posts

This should be an easy question, but for some reason I'm double guesing myself.

New construction single family home: 2 electrical panel boxs next to each other 1 is 200amp the other 100amp and is not a sub. So this means the house has 300amps, right? Also new construction should have AFI for the bedroom breakers right.

Download Attachment: icon_photo.gif 100amp.JPG

89.03 KB

Download Attachment: icon_photo.gif 200amp.jpg

89.58 KB

Download Attachment: icon_photo.gif outside.jpg

44.39 KB

Link to post
Share on other sites

Strictly speaking, I would state it as having a 100A service and a 200A service. Sure, that gives you 300A, but it's not on one service, so that would potentially be misleading.

It would help the client if you indicate the section(s) of the house served by each service. That might also help you understand why they are doing this - how big is the house? Is there a special need - bowling alley, grow-room, film studio???

And yes, AFI in the bedrooms - even though the debate as to their worth is ongoing...

Originally posted by AHIS

This should be an easy question, but for some reason I'm double guesing myself.

New construction single family home: 2 electrical panel boxs next to each other 1 is 200amp the other 100amp and is not a sub. So this means the house has 300amps, right? Also new construction should have AFI for the bedroom breakers right.

Link to post
Share on other sites

Thnak you, I'll list it as two seperate services and not as a grand total. The house is around 3500 sqft + an unfinished basement with nothing special at all, except that it has seperate furnaces and a/c for each floor. I don't know what it was wired this way - room to expand I guess. Oh, the pictures are sideways for some reason not the boxs.

Link to post
Share on other sites
Originally posted by AHIS

This should be an easy question, but for some reason I'm double guesing myself.

New construction single family home: 2 electrical panel boxs next to each other 1 is 200amp the other 100amp and is not a sub. So this means the house has 300amps, right?

Yes. You're right. Be aware that it's possible that the meter and laterals are capable of providing 400 amps. The service is limited to 300 amps by the two main breakers in your pictures.

Also new construction should have AFI for the bedroom breakers right.

Yes, if that town has adopted 210.12(B).

No, if they haven't. I understand that there are some places that have snipped that section out of their code.

- Jim Katen, Oregon

Link to post
Share on other sites
Originally posted by ozofprev

Strictly speaking, I would state it as having a 100A service and a 200A service.

Nope. A single service can have multiple main panels. It can even have multiple meters.

As a general rule, a building can only have one service. There are several exceptions to this rule, but none of them apply to dwellings. Read all about it in 230.2.

- Jim Katen, Oregon

Link to post
Share on other sites
Originally posted by Bain

The incoming service is likely rated at 400 amps. Looks to me like the electrician wanted to save a couple of hundred bucks by not installing two 200-amp panels, which is the typical set up around here.

What probably happened is that, at the design stage or at the plan review stage, someone calculated that this house would require a 300-amp service. (Note the rough-in for two AC units. This might be a big house.) So that's what the electrician installed. It's probably more than ample.

- Jim Katen, Oregon

Link to post
Share on other sites

Yes, there is only one service to a dwelling. Still, the report is written for a client who probably knows squat about 'service,' so you report 300A (or 400 if you can confirm) service and then describe the panels for the completed picture. I sit corrected. Thanks Jim!

Originally posted by Jim Katen

Originally posted by ozofprev

Strictly speaking, I would state it as having a 100A service and a 200A service.

Nope. A single service can have multiple main panels. It can even have multiple meters.

As a general rule, a building can only have one service. There are several exceptions to this rule, but none of them apply to dwellings. Read all about it in 230.2.

- Jim Katen, Oregon

Link to post
Share on other sites

Hi Steven,

It's not how you phrase it. It's a matter of stating the facts. If there is only one lateral, then by definition, there is only one service. Can't rephrase that (no matter how incompetently I tried).

But then, complete the picture with information about the distribution of this single service. What fuses/CBs protect the unit you are inspecting? Are there multiple meters? What is your professional opinion as to the ability of the single service to provide adequately for all units?

Originally posted by StevenT

Thanks Gary,

I tend to agree with you, but if there was a two, three, ... family house with separate service for each unit, wouldn't there be only one lateral?

Or is it all in how you phrase it?

Service to the building... service to the unit?

Link to post
Share on other sites
  • 5 weeks later...

This is a single service, the meter enclosure is a 320A Conin. and a 400A Non-Cont. enclosure. Chances are the service calculation came up as under 300A or they used the optional method to decrease it below 300A or simply to effect the installation, only the electrician knows this.

AS for sizing this service you really should deal in Capacity and Rating......this enclosure will have a capacity based on the combined components of the system based. Now, you have to post the size of the SE Conductors, Panel Rating, OCPD Rating and (2) others we will throw out......because it is latteral and you can't see them.

This service has a rating of 300A based on the weakest link designation....based on what he has posted....the capacity could be different but in this case 300A based on the enclosure ratings has to govern here without the other information.

Check out my basic video on this....simplified -http://www.theelectricalguru.com/video.html

Also if new construction make sure they re-identify those while conductors going to the breakers...... I did not look at the images any furthur than those issues.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...