Tap Rule Question

[wwhitney]

Just verifying a No Fuse disconnect could serve as the tap splice prior to landing on overcurrent protection without issue per the 10' tap rule.

That I'm a little unclear on, as a disconnect is a bit different than just a splice. But the wording of the 10' tap rule is a little broader than the 25' tap rule.

Cheers, Wayne

 

[jap]

That I'm a little unclear on, as a disconnect is a bit different than just a splice. But the wording of the 10' tap rule is a little broader than the 25' tap rule.

Cheers, Wayne

In a group metering setup the tabs on the Meter itself would be a tap splice seeing as how the smaller buss bars tapped off of the main buss bars land on the line side of the meter socket first and not the overcurrent protection of the tenant breaker.

Jap>

 

[electrofelon]

In a group metering setup the tabs on the Meter itself would be a tap splice seeing as how the smaller buss bars tapped off of the main buss bars land on the line side of the meter socket first and not the overcurrent protection of the tenant breaker.

Jap>

I would say a meter bank is not subject to the tap rules. There is a product standard for that and the rules for building them would be found there.

 

[jap]

I would say a meter bank is not subject to the tap rules. There is a product standard for that and the rules for building them would be found there.

If the group metering is not subject to the tap rules, why then are we required to follow the tap rules?

Oh well,,,

Jap>

 

[jap]

If the group metering is not subject to tap rules due to the standards for building them there shouldn't be an allowance to field tap the buss of a group metering setup.

Who knows, maybe it isn't allowed.

Jap>

 

[electrofelon]

If the group metering is not subject to tap rules due to the standards for building them there shouldn't be an allowance to field tap the buss of a group metering setup.

Who knows, maybe it isn't allowed.

Jap>

I am failing to see why you are lumping together the construction of a factory assembled piece of equipment following a product standard, to field installed conductors coming off a bus.

 

[Strathead]

I am wondering if 240.21(B) Feeder Taps applies to my situation.

We are trying to tap the bus of a multi-meter, service switchboard which has a main fuse (1,000A). There are multiple meter sockets but no space for an additional one. We are trying to tap the bus and the tap conductor length and size is an issue. There isn't much space around this switchboard so the enclosed meter-main box would have to be about 10 feet from the switchboard. The tap conductor length would be greater than 10 feet.

Is this whole situation governed by the rules spelled in 240.21(B) feeder taps? Or are these considered service conductors and so governed by 240.21 (D) Service Conductors which just refers you to 230.91 which doesn't really specify any restrictions on lengths.

This is probably a stupid question, but this setup is indoors, right?

 

[jap]

I am failing to see why you are lumping together the construction of a factory assembled piece of equipment following a product standard, to field installed conductors coming off a bus.

Is field tapping the bussing of a factory assembled group metering setup allowed?

Jap>

 

[electrofelon]

Is field tapping the bussing of a factory assembled group metering setup allowed?

Jap>

I don't see why not, what code section would you cite? There is a potential issue on how exactly the tap is made if there are not existing lugs available. The AHJ may have the right to request a field evaluation. See this document (may be specific to switchboards I can't remember).

https://code-authorities.ul.com/wp-content/uploads/2014/04/ul_TappingBusbarConsiderations.pdf

 

[jap]

I don't see why not, what code section would you cite? There is a potential issue on how exactly the tap is made if there are not existing lugs available. The AHJ may have the right to request a field evaluation. See this document (may be specific to switchboards I can't remember).

https://code-authorities.ul.com/wp-content/uploads/2014/04/ul_TappingBusbarConsiderations.pdf

I don't see why not either, and, I'm no looking to cite any code.

I was Just trying to get clarity in my head the rule if you do decide to tap.

I started thinking of the 25' tap which requires the tap to land on an overcurrent protection device first.
On a group metering tap from the buss bars to a combo meter main, the tap would not land on the overcurrent protection first. It would land on the line side terminals of the meter in the combo first.
That's what prompted my question of a NF disconnect being allowed to be in line prior to the overcurrent protection since it mimics the line and load tabs on the meter to a tenant main as a tap splice.
If the first landing point of the feeder tap had to be the OCPD, and, Not a terminal block or anything in between, then, you couldn't use the 25' tap rule at all.

Then, we're down to a 10' tap rule which is much more forgiving.

That rule indicates "not less than the rating of the device supplied by the tap conductors or the OCPD "at the termination of the tap conductors".
My question then was can there be anything between the tap at the group metering buss and the overcurrent protection device located in the combo meter/main your feeding.

If you consider the tap conductor has not been altered by running it through a terminal block, NF disconnect, or, Tabs on the meter, then, nothing about the rule would prohibit you from doing so.
Those points would simply be an extension of the tap conductor.

In short I say, Tap it.

As others have said the only determination is whether your dealing with Service Conductors or Feeder Conductors, which I've now discovered they are Feeder conductors on the load side of the OCPD in a group metering setup, whereas before I was at the understanding that in a group metering setup they were actually service conductors all the way to the line side of the meter bases.

I learn something new here every day and appreciate it.

Thanks,
Jap>

 

[kwired]

Does the 10' Tap rule require the tap conductor to land directly on an overcurrent device, or, can it land on a terminal block and then extend the same size tap conductor to the overcurrent device?

Jap>

Tap rule does not apply to service conductors, so one must confirm if this is taps to service conductors or an actual feeder tap first.

If a feeder tap, non of the tap rules allow "tapping a tap". I suppose as mentioned you could splice a single conductor with same size conductor and still consider the whole thing a tap conductor, as long as you did not reduce conductor size across the splice. You wouldn't be able to start over with length of the tap at said splice. You could say splice off a 200 amp feeder with a 200 amp conductor then reduce to a smaller conductor - the feeder tap in that case doesn't start until you are at a point where the conductor has less ampacity then the supply side overcurrent protection.

 

[jap]

Tap rule does not apply to service conductors, so one must confirm if this is taps to service conductors or an actual feeder tap first.

If a feeder tap, non of the tap rules allow "tapping a tap". I suppose as mentioned you could splice a single conductor with same size conductor and still consider the whole thing a tap conductor, as long as you did not reduce conductor size across the splice. You wouldn't be able to start over with length of the tap at said splice. You could say splice off a 200 amp feeder with a 200 amp conductor then reduce to a smaller conductor - the feeder tap in that case doesn't start until you are at a point where the conductor has less ampacity then the supply side overcurrent protection.

Lets say he taps the load side buss bars of that 1000a OCPD with a larger than needed tap conductor to to combo meter/main.

He's going to be landing his tap conductor on the line terminals of the meter in his newly installed meter/main.

The tap conductor would not reach the OCPD ( or tenant main) in the meter/main until the meter is installed.

I'm sure it is, but, you'd have to somehow determine that the stab tabs on the power company's meter are rated at or more than the tap conductor the contractor installed.

Otherwise the meter stab tabs themselves would be tapping a tap.

Jap>

 

[augie47]

I guess it all falls back on an install we did a few years back in the (6) movement or less days, where the Power Company would not connect to our 8 socket group metering setup because it had a single main switch type OCPD in the tap box.

It was drawn that way on the plans since there were more than 6 meter/mains and the designer felt it needed a single service disconnect.

In a group metering setup that disconnect generally incorporates overcurrent protection.

The POCO viewed the 8 individual tenant mains as their own individual service disconnects to the tenant spaces (regardless of the number of) and would not allow a switch of any type in their service conductors between the load side of their Xfmr and the line side of the meter bases where they plugged their meters in.

We have group metering of 15 or more meter/mains in our area that do not have a single means of disconnect in the tap box.

The example they gave was as if I were to build 8 individual meter risers next to each other on the back of the lease space, they would swing a service overhead from their pole top XFMR to the risers and connect them all together at the weather heads.

Then said " in that scenario, where do you see a switch of any type in the "Service Conductors" between our transformer and the line side of the 8 individual service disconnects ?",,,,, "You don't".

For that reason, I've always viewed the conductors from their transformer to the line side of a single Service Disconnecting means with overcurrent protection, or, in the case of group metering, the line side of the individual Tenant Mains as the service conductors.

You would think that if the power company actually did view the load side of a single disconnecting means with OCP in a group metering setup as the actual Service Disconnect (where their responsibility of the Service Conductors ends and the customer's responsibility of Feeders begins) , they would make the customer be responsible for the metering such as is the case where EMON metering is installed to meter "Feeder" loads.

Oh well,,,


Jap>

In our area at one time it was common to have multiple meters (>6), no main, no individual OCPDs, and each meter having a service cable to individual apartments with that apartment panel meeting 230.70 (all were on the interior of outside walls).
It was ruled compliant under 230.40 Exception 1

 

[jap]

In our area at one time it was common to have multiple meters (>6), no main, no individual OCPDs, and each meter having a service cable to individual apartments with that apartment panel meeting 230.70 (all were on the interior of outside walls).
It was ruled compliant under 230.40 Exception 1

Here also, although in our area that setup can be witnessed on the outside walls as well.

Thanks Augie,

Jap>

 

[electrofelon]

That rule indicates "not less than the rating of the device supplied by the tap conductors or the OCPD "at the termination of the tap conductors".
My question then was can there be anything between the tap at the group metering buss and the overcurrent protection device located in the combo meter/main your feeding.

If you consider the tap conductor has not been altered by running it through a terminal block, NF disconnect, or, Tabs on the meter, then, nothing about the rule would prohibit you from doing so.
Those points would simply be an extension of the tap conductor.

.

Thanks,
Jap>

Yeah we have discussed that before and some argue you cannot splice a tap because then the conductor is terminating on a splice connector not an OCPD. I don't subscribe to that severe and interpretation but something like self-contained meter is a little more of a gray area I agree.

 

[kwired]

Lets say he taps the load side buss bars of that 1000a OCPD with a larger than needed tap conductor to to combo meter/main.

He's going to be landing his tap conductor on the line terminals of the meter in his newly installed meter/main.

The tap conductor would not reach the OCPD ( or tenant main) in the meter/main until the meter is installed.

I'm sure it is, but, you'd have to somehow determine that the stab tabs on the power company's meter are rated at or more than the tap conductor the contractor installed.

Otherwise the meter stab tabs themselves would be tapping a tap.

Jap>

What you described is not a feeder tap. Is just an extension of the feeder. A feeder tap conductor will be one that has less ampacity than the required overcurrent protection on supply side of the conductor.

 

[jap]

What you described is not a feeder tap. Is just an extension of the feeder. A feeder tap conductor will be one that has less ampacity than the required overcurrent protection on supply side of the conductor.

No, it would be a tap unless he's planning on bringing a 1000 amp rated conductor to the 200 or 320 amp rated self contained meterbase he's going to be adding to the lineup.

Like bringing a 250 mcm tap conductor to a 200a rated socket for example.

If the stabs on the meter were truly rated at only 200 amps it would be less than the rating of the 250 mcm tap conductor and you'd be tapping a tap.

JAP>

 

[kwired]

No, it would be a tap unless he's planning on bringing a 1000 amp rated conductor to the 200 or 320 amp rated self contained meterbase he's going to be adding to the lineup.

Like bringing a 250 mcm tap conductor to a 200a rated socket for example.

If the stabs on the meter were truly rated at only 200 amps it would be less than the rating of the 250 mcm tap conductor and you'd be tapping a tap.

JAP>

Yes the conductor needs to be 1000 amp conductor to be an extension of the feeder.

Tap rules kind of require you to land the tap at an overcurrent device. I don't know if a combo meter/main would count as landing in an overcurrent device or not. I think definitely a stand alone meter socket probably wouldn't.

 

[jap]

Yes the conductor needs to be 1000 amp conductor to be an extension of the feeder.

Tap rules kind of require you to land the tap at an overcurrent device. I don't know if a combo meter/main would count as landing in an overcurrent device or not. I think definitely a stand alone meter socket probably wouldn't.

That's been my point this whole time.

JAP>

 

[kwired]

That's been my point this whole time.

JAP>

I can miss the whole picture sometimes.