Taps on Service Conductors

[KasseemF]

I want to know what the code says about taps on service conductors.

I have an electrical installation that has a 200A meter base without breaker and on the load side there is a junction box where a 1/0 AWG service is tapped by at #2 and #4 AWG conductor that both go into panelboxes to 80 and 70 Amp breakers respectively.

Is this installation up to code?

 

[Volta]

I want to know what the code says about taps on service conductors.

I have an electrical installation that has a 200A meter base without breaker and on the load side there is a junction box where a 1/0 AWG service is tapped by at #2 and #4 AWG conductor that both go into panelboxes to 80 and 70 Amp breakers respectively.

Is this installation up to code?

Assumptions:
The panelboards are grouped.
The equipment and system are grounded properly.
The loads are calculated not to exceed 150 amps.
Everything else is ok.

IMO the rating of the 1/0 needs to be considered at 60 deg C if connected to other conductors used at that temp., with some exception allowed by 310.15(A)(2).

With that thought, I'd expect that in actuality the terminations are likely rated at 75 degrees, so may be a non-issue.

I don't see a problem.

 

[Dennis Alwon]

To add to Volta-- where are the panelboxes. Would they satisfy 230.70(A)(1).

 

[steve66]

240.21 (A) lists taps for branch circuits. 240.21(B) lists taps for feeders. Neither mention service conductors. So I assumed the NEC did not allow for taps on service conductors.

But of course the power company has their own set of rules, so if they own the 1/0 wire, almost anything could probably fly with their permission.

Also, the handbook has exhibit 250.27, which seems to show a tap of a #3 onto a 3/0 service conductor.

I'm interested in how others see this. I'm not sure I really understand when a tap would be allowed on a service conductor.

 

[augie47]

The rules Volta listed pretty much dictate the situation.
When you have multiple service disconnects, taps in j boxes or raceways are common. So long as all condcutors are adequate for the calculated load and individual overcurrent devices to which they are tapped and all the rules of 230 are met there is no Code problem.
I see it very often with a outside wireway and 2 thru 6 meters/service disconnects tapped from 1 set of entrance conductors.

 

[Smart $]

... I'm not sure I really understand when a tap would be allowed on a service conductor.

Whenever one needs to be made

230.33 Spliced Conductors. Service-lateral conductors shall be
permitted to be spliced or tapped in accordance with
110.14, 300.5(E), 300.13, and 300.15.

230.46 Spliced Conductors. Service-entrance conductors
shall be permitted to be spliced or tapped in accordance
with 110.14, 300.5(E), 300.13, and 300.15.

 

[steve66]

The rules Volta listed pretty much dictate the situation.
When you have multiple service disconnects, taps in j boxes or raceways are common. So long as all condcutors are adequate for the calculated load and individual overcurrent devices to which they are tapped and all the rules of 230 are met there is no Code problem.
I see it very often with a outside wireway and 2 thru 6 meters/service disconnects tapped from 1 set of entrance conductors.

I want to believe, but I weighing the first paragraph of 240.21 against the road that 240.21(D) seems to lead one down.

If its a customer owned tap, I just don't see where it is real clear. 230.90 and 230.91 also seem to give some weight to allowing it, but it just doesn't seem to come right out and say it.

Of course, again, depending on where the service point is, the utility can do almost anything they want.

Steve

 

[steve66]

Whenever one needs to be made

​

Smart$:

Seems cut and dry at first, but doesn't it seem very odd that those paragraphs reference all those other paragraphs, yet don't make any mention of 240.21??

If you look at the definition of "tap conductor" in article 240, it starts out saying "As used in this article....."

So the words "tapped" in Article 230 don't necessarly have anything to do with "tap conductors" as defined and discussed in Article 240.

Steve

 

[augie47]

One thing to keep in mind is Art 240 is for tap conductors with OCP devices ahead of them (see 240.2 "Tap Conductors") and not service conductors. Smart$ 's post covers taps to service conductors.

 

[Pierre C Belarge]

240.21 is FEEDER Taps

When working with service entrance conductors, we SPLICE SEC, we do not tap them.
Service entrance conductors do not have OCP ahead of the conductors.


Typically speaking the footage requirements of 10' and 25' are for feeders, and splicing of service conductors do not follow those requirements.

 

[Smart $]

...

When working with service entrance conductors, we SPLICE SEC, we do not tap them.
Service entrance conductors do not have OCP ahead of the conductors.

...

Not true. You are using the Article 240 definition, which applies only to Article 240 as stated in the definition.

I see service conductor taps as wire-to-wire connections where the load side conductor has a lesser ampacity rating than the line side conductor (but not technically defined by the NEC).

 

[steve66]

OK, I've thought about it a little more, and my faith has been renewed, so today I'm a believer

So just to be sure I've got this right, service taps (or splices for Pierre ) can be made without regard to either the lengths or current limits of 240.21??

So I could legally take a #6 tap (or splice) from a 2000A service, and run it 1000' outside, and another 10' inside a building to a 60A fused disconnect? Is that right?

Steve

 

[Volta]

OK, I've thought about it a little more, and my faith has been renewed, so today I'm a believer

So just to be sure I've got this right, service taps (or splices for Pierre ) can be made without regard to either the lengths or current limits of 240.21??

So I could legally take a #6 tap (or splice) from a 2000A service, and run it 1000' outside, and another 10' inside a building to a 60A fused disconnect? Is that right?

Steve

Pretty much. Except for potential issues of grouping of disconnects, nearest the point of entrance, etc., the #6 is ok.

 

[Pierre C Belarge]

240.2 Definitions. As used in this article, a tap conductor is defined as a conductor, other than a service conductor.., that has overcurrent protection ahead of its point of supply that exceeds the value permitted for similar conductors that are protected as described elaewhere in 240.4

240.21 Location in Circuit. (that is, location of overcurrent protection)

(B) Feeder Taps.

Feeders conductors can be tapped or spliced.
Service conductors are spliced.

 

[Volta]

240.2 Definitions. As used in this article, a tap conductor is defined as a conductor, other than a service conductor.., that has overcurrent protection ahead of its point of supply that exceeds the value permitted for similar conductors that are protected as described elaewhere in 240.4

240.21 Location in Circuit. (that is, location of overcurrent protection)

(B) Feeder Taps.

Feeders conductors can be tapped or spliced.
Service conductors are spliced.

Or tapped 230.46, just without a definition .

 

[Pierre C Belarge]

Or tapped 230.46, just without a definition .

Touche......

 

[Smart $]

Or tapped 230.46, just without a definition .

230.33, too. I posted 'em earlier in this thread.

As a side note, 230.33 is for service-lateral conductors and 230.46 is for service-entrance conductors... so I guess overhead service conductors are not permitted to be spliced or tapped :roll:

 

[Volta]

230.33, too. I posted 'em earlier in this thread.

As a side note, 230.33 is for service-lateral conductors and 230.46 is for service-entrance conductors... so I guess overhead service conductors are not permitted to be spliced or tapped :roll:

Per Article 100 I think an overhead service conductor is considered a service-entrance conductor on the load side of the service-point.