Tap Service

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Alwayslearningelec

Senior Member
Location
NJ
Occupation
Estimator
Installing a small new service.

Where they show to make the tap( between service end box and disconnect section I'd assume there is no existing conduit here as it all one switchboard with service end box attached. Is it even possible to price this tap without knowing the existing conductors? That aside what material would you use to perform the tap? This tap wouldn't be a type that "clamps/bites" onto the existing conductors, correct? Cutting them and installing some sort of tap block would be required? Thank you.

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Given the information on your drawing there is no way you can accurately price this. Are you connecting to bus or conductors? If it's condcutors how many sets?

I'm also amazed at how many engineers don't understand that there are no EGC's on the line side of a service disconnect. :rolleyes:
 
infinity said:
Given the information on your drawing there is no way you can accurately price this. Are you connecting to bus or conductors? If it's condcutors how many sets?

I'm also amazed at how many engineers don't understand that there are no EGC's on the line side of a service disconnect. :rolleyes:
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There would be no #1G?
Why would the # of existing sets matter? I know I have 2 new sets.
So it could be either a tap on the existing bus OR existing conductors?
 
Alwayslearningelec said:
1) There would be no #1G?
2) Why would the # of existing sets matter? I know I have 2 new sets.
3)So it could be either a tap on the existing bus OR existing conductors?
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1) There is no EGC ahead of a service disconnect so no there should not be a #1 AWG conductor in the service raceway. In fact installing one is a violation.
2) You're adding two sets but you need to know how many sets are existing if they're connecting to conductors. If the existing has 6 sets you need to "tap" all six sets not just two of them.
3) Yes, you need to determine what you're connecting to. A bus tap may require additional bus to be added to connect your "tap" conductors. For existing conductors see #2.
 
infinity said:
1) There is no EGC ahead of a service disconnect so no there should not be a #1 AWG conductor in the service raceway. In fact installing one is a violation.
2) You're adding two sets but you need to know how many sets are existing if they're connecting to conductors. If the existing has 6 sets you need to "tap" all six sets not just two of them.
3) Yes, you need to determine what you're connecting to. A bus tap may require additional bus to be added to connect your "tap" conductors. For existing conductors see #2.
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1. What code section for no EGC ahead of service disconnect.
2. I'm a little lost about connecting 6 sets(if there were that qty existing) to 2 sets. Visually I can't picture how that would work as I'm thinking it would have to be a one for one tap.
 
You must tap all conductors which are in parallel, so the new load is shared equally across all of them.

This looks to involve a utility service entrance. Do you know if they have anything to say about adding a meter after their CTs, or is the meter provided by you?
 
jim dungar said:
You must tap all conductors which are in parallel, so the new load is shared equally across all of them.

This looks to involve a utility service entrance. Do you know if they have anything to say about adding a meter after their CTs, or is the meter provided by you?
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They show a meter. I’m not sure yet if it’s provided by utility . Will CT’s have to be added here as well?
 
For the code section re no EGC ahead of the service disconnect see the definition of an EGC in Article 100.

The SLD shows a new service disconnect, not a new service.

I question whether the person who made the drawings is qualified and competent for the following reasons:
- the EGC thing
- appears to be requesting new utility metering in series with existing metering
- appears to being invoking a tap rule that doesn't apply
- didn't denote the location of the service end box on the plan view, which is critical info
- nonetheless appears to have stipulated less than 10ft 'tap' while denoting a location for the new disco that is more than 10ft from likely tap location. Suspicious.
- possibly denoting a location for the new equipment that blocks the required egress from the room, depending on how precise and to scale the drawing is
- seems to have specified the new service entrance to be twice the size it needs to be for the load. Which might be for future, but still.
 
jaggedben said:
For the code section re no EGC ahead of the service disconnect see the definition of an EGC in Article 100.

The SLD shows a new service disconnect, not a new service.

I question whether the person who made the drawings is qualified and competent for the following reasons:
- the EGC thing
- appears to be requesting new utility metering in series with existing metering
- appears to being invoking a tap rule that doesn't apply
- didn't denote the location of the service end box on the plan view, which is critical info
- nonetheless appears to have stipulated less than 10ft 'tap' while denoting a location for the new disco that is more than 10ft from likely tap location. Suspicious.
- possibly denoting a location for the new equipment that blocks the required egress from the room, depending on how precise and to scale the drawing is
- seems to have specified the new service entrance to be twice the size it needs to be for the load. Which might be for future, but still.
Click to expand...
Thanks.
1. So having a new service disconnect does not mean you have a new service?
2. Can you explain more what you mean by the metering?
3. 10' tap rule referenced is not applicable to this situation?
 
Alwayslearningelec said:
Thanks.
1. So having a new service disconnect does not mean you have a new service?
2. Can you explain more what you mean by the metering?
3. 10' tap rule referenced is not applicable to this situation?
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1) yes the service is existing you're adding an additional service disconnect.
2) the metering looks typical for ConEd.
3) there are no taps on service conductors they are service conductors spliced to the existing service conductors. 10' may be the acceptable limit in the jurisdiction for length of service conductors although I've seen over 20'.
 
infinity said:
1) yes the service is existing you're adding an additional service disconnect.
2) the metering looks typical for ConEd.
3) there are no taps on service conductors they are service conductors spliced to the existing service conductors. 10' may be the acceptable limit in the jurisdiction for length of service conductors although I've seen over 20'.
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So metering looks ok?
So when they are saying "tap" it's really not a tap it's a splice? If so why is not a tap? Because, as you said, you can't "tap" service conductors? Where is that in the code?

Thanks.
 
The NEC defines a "tap" in 240.2 and that definition includes an overcurrent device ahead of the conductors which you don't have.
In reality you are "tapping" but in Code=Speak it's just a connection so the service conductor rules apply and not the tap rules.
As mentioned the allowable length is an AHJ call.
 
infinity said:
1) There is no EGC ahead of a service disconnect so no there should not be a #1 AWG conductor in the service raceway. In fact installing one is a violation.
2) You're adding two sets but you need to know how many sets are existing if they're connecting to conductors. If the existing has 6 sets you need to "tap" all six sets not just two of them.
3) Yes, you need to determine what you're connecting to. A bus tap may require additional bus to be added to connect your "tap" conductors. For existing conductors see #2.
Click to expand...
Again on the # 1 EGC. There should be no EGC on the LOAD side of the 600A disconnect or from where the "tap/splice" happen onward? Thanks.
 
Alwayslearningelec said:
So metering looks ok?

Thanks.
Click to expand...

Maybe something in the drawing is misleading, but I read it to show a self-contained 600A meter socket on the load side of the existing CT section. I would presume the CT meter monitors everything that goes through the CT section. In that case the new meter would be counting energy that's already counted by the CT meter. So if they are both Con Ed meters then Con Ed would be getting paid twice for the same energy.
 
jaggedben said:
Maybe something in the drawing is misleading, but I read it to show a self-contained 600A meter socket on the load side of the existing CT section. I would presume the CT meter monitors everything that goes through the CT section. In that case the new meter would be counting energy that's already counted by the CT meter. So if they are both Con Ed meters then then Con Ed would be getting paid twice for the same energy.
Click to expand...
They want to separately meter those 2 sets . How else do you suppose they do that? But I think I see what you mean those sets would be getting metered twice???
 
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