Inlet Service Capacity

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#1

Originally Posted By: bsilowash
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, by Norman Becker, says that “Once the panel cover has been removed, the actual inlet service capacity can be determined. It depends on the size of the inlet service wire only, not on the rated capacity of the panel box or the size of the fuse or circuit breaker used for the master disconnect, if there is on.”


That's great, but assuming that you want to know if the rated capacity of the panel or the size of the master disconnect was matched to the size of the inlet service wire, how can you tell?

My inlet service wires are not labelled to indicate size, and I can't measure the diameters. So how do you folks determine the inlet capacity?

#2

Originally Posted By: gbeaumont
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Hi Brian,


The maximum ampacity of a supply it determined by the lowest rated component, so if the panel is rated for 150 amps but the main disconnect is rated for 100 amp and the meter and SEC are only 60 amp then the supply would have a maximum capacity of 60 amp.
Conversely (and some what rarer) if you have a 150 amp meter and SEC but only a 100 amp main disconnect and panel then the maximum amperage would be 100 amps.

As to determining the size of the service enterance conductors occasionally you can read the wire, but more typicaly most inspectors carry a plastic wire gauge to slip over the conductor to tell them what size it is and therefore what the rating would be.

Here is a link to what I'm talking about:

http://www.professionalequipment.com/xq/ASP/ProductID.49/id.5/subid.203/qx/default.htm

Regards

Gerry

--
Gerry Beaumont
NACHI Education Committee
e-mail : education@nachi.org
NACHI phone 484-429-5466

Inspection Depot Education
gbeaumont@inspectiondepot.com

"Education is a journey, not a destination"

#3

Originally Posted By: jpeck
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bsilowash wrote:
The Complete Book of Home Inspections, by Norman Becker, says that "Once the panel cover has been removed, the actual inlet service capacity can be determined. It depends on the size of the inlet service wire only, not on the rated capacity of the panel box or the size of the fuse or circuit breaker used for the master disconnect, if there is on."


When someone who purports to teach others about something, they should at least know and use proper and common terminology, and get it right.

He was wrong on both.

"inlet service wire"????????? Oh my goooooooooddddd, and he is TEACHING HIs?

As Gerry stated, it is the SMALLEST rated components of the components in the service.

I would throw that book away (unless there is some redeeming good information in there, and that is not for the unknowing to decide, but for an experienced and knowledgeable person to review and decide).

Anybody with knowledge and experience read that book? What say you? Is that a throw-a-way or a keeper because it has other redeeming value?

--
Jerry Peck
South Florida
#4

Originally Posted By: kmcmahon
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It’s not a home inspector tutorial…it’s a home buyer/seller self inspection manual. Just clarifying. icon_wink.gif


and mines on the shelf collecting dust after I saw it was for home buyer/seller and not for Home Inspectors.

--
Wisconsin Home Inspection, ABC Home Inspection LLC

Search the directory for a Wisconsin Home Inspector

#5

Originally Posted By: Mike Parks
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Jerry


"keeper because it has other redeeming value?"

It will balance the pots that my wife uses for her plants.

Mike P.

#6

Originally Posted By: Bob Badger
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The only electrical ‘inlet’ I know of is like this.


![](upload://4QOpCDA3BHTwZ9NGl6Unt3neNm.jpeg)

Just the opposite of an 'outlet'

--
Bob (AKA iwire)
ECN Discussion Forums
Mike Holt Code Forum

#7

Originally Posted By: Mike Parks
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Bob


I'm sorry but I could not resist.

Show me the opposite of an outlet (per 100). ![icon_wink.gif](upload://ssT9V5t45yjlgXqiFRXL04eXtqw.gif)

Would that be a surfce mounted box?

Mike P.

#8

Originally Posted By: Bob Badger
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Never resist Mike. icon_lol.gif


This device will not meet the definition of outlet, Receptacle or Attachment Plug.

However you will find it called a "flanged surface inlet" in article 551.46

--
Bob (AKA iwire)
ECN Discussion Forums
Mike Holt Code Forum

#9

Originally Posted By: roconnor
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jpeck wrote:
Anybody with knowledge and experience read that book? What say you? Is that a throw-a-way or a keeper because it has other redeeming value?

There are very few decent home inspection books. The Becker book is not a bad overall introduction book, although I don't agree with some of the terminology and statements ... like the one noted above.

I think the intended point was that you need to also look at the size of the incoming service entrance feeder, and not only the service panel and main disconnect rating.

--
Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee

I am absolutely amazed sometimes by how much thought goes into doing things wrong
#10

Originally Posted By: jtedesco
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I too was not happy when I read the first post and agree with the replies so far!


The language of the trade (definitions) is important and like road signs we must learn to identify.

We may want to consider revising the electrical terms used in any NACHI publication so that we don't drive of of the rode!

I will take a look into my inspection book and see if the glossary there can be considered for use by NACHI members.Then we can ask for input from the members so that it can be expanded.

PS: I realize there will be some different interpretations as to what "Soda" is versus, the term "Pop"

Question: What is a "heavy up"?

--
Joe Tedesco, NEC Consultant

www.nachi.org/tedescobook.htm

#11

Originally Posted By: roconnor
This post was automatically imported from our archived forum.


jtedesco wrote:
Question: What is a "heavy up"?

To make heavier ... ![icon_lol.gif](upload://zEgbBCXRskkCTwEux7Bi20ZySza.gif) ... e.g. increase the wire size ...

Brian ... good question, and pick-up of a poorly worded section of that book. Also, welcome! Glad to see another PE on the board too. Gerry is gonna be just thrilled, cause he likes the nifty evaluation gadgets some of us have ... ![icon_lol.gif](upload://zEgbBCXRskkCTwEux7Bi20ZySza.gif)

Keep in mind that those gages Gerry mentioned work with the bare wire size. Many, including me, consider it hazardous for an HI to stick anything inside a panel. Particularly near the exposed ends of feeder wires, even with plastic gages ... because that means your hands will be inside the panel near exposed energized wires. IMHO it's better to estimate wire size based on what you can see and a comparison of the gages with an insulated section of feeder wire ... visualizing what the bare wire would be ...

Just my 2-nickles

--
Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee

I am absolutely amazed sometimes by how much thought goes into doing things wrong
#12

Originally Posted By: gbeaumont
This post was automatically imported from our archived forum.


I think it would be preferable for most HI’s to go down to their local electric supply house and pick up small lengths of the more common SEC wire sizes and use those known samples to visualy compare wuth what is seem in a panel.


Regards

Gerry

--
Gerry Beaumont
NACHI Education Committee
e-mail : education@nachi.org
NACHI phone 484-429-5466

Inspection Depot Education
gbeaumont@inspectiondepot.com

"Education is a journey, not a destination"

#13

Originally Posted By: roconnor
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Gerry … I…I…I actually liked your first recommendation for gages, and I have a set of them … real handy.


Maybe it's a British thing, but you are kidding about holding a piece of wire in your hand anywhere near a live panel, right ... ![icon_eek.gif](upload://yuxgmvDDEGIQPAyP9sRnK0D0CCY.gif)

--
Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee

I am absolutely amazed sometimes by how much thought goes into doing things wrong

#14

Originally Posted By: Mike Parks
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Robert


You would really enjoy watching the sparkies here add a #4 copper (for bonding) to an already live panel.

Mike P.

#15

Originally Posted By: Bob Badger
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Adding NM cable to live panels scares me, to much bare copper on the loose. icon_eek.gif


Give me MC cable with it's fully insulated ground any day.

--
Bob (AKA iwire)
ECN Discussion Forums
Mike Holt Code Forum

#16

Originally Posted By: Mike Parks
This post was automatically imported from our archived forum.


Bob


How I do it is:

Cut the jacket.
Pull enough of the jacket to cover the ends.
Pull it into the panel.
Remove the jacket.
Place the jacket over the egc.
Pull the egc to where I need it.
Remove the jacket.

Make sense?

Mike P.

#17

Originally Posted By: roconnor
This post was automatically imported from our archived forum.


Mike Parks wrote:
You would really enjoy watching the sparkies here add a #4 copper (for bonding) to an already live panel.

I see sparkies do things on live 480/277V commercial service equipment sometimes that scares the hell out of me. I usually shudder, make some kind of comment, and walk away. I don't want to be in the blast zone and I'm not the safety police ... ![icon_rolleyes.gif](upload://iqxt7ABYC2TEBomNkCmZARIrQr6.gif)

--
Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee

I am absolutely amazed sometimes by how much thought goes into doing things wrong