If terminations occur in an LB, why is it not necessary to ground

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YoungSinatra

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If terminations occur in an LB, why is grounding not required? Teacher said everywhere that a connection is made, there has to be a form of grounding but he doesn’t know the answer as to why you don’t need a ground in an LB
 
Not sure where one would have terminations in a LB (splice occasionally) In any event, if it's a metallic LB and part of a metallic conduit system it would be "grounded" via the conduit system.
 
Unless it's in the middle of a non-metallic run. For example, PVC underground comes out of the ground and through a wall. The riser and LB are metallic for damage protection. Once through the wall, PVC is again used.
 
infinity said:
That would be different, it would require some type of grounding even without splices in the conduit body.
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Best option would be to avoid the situation in the first place and go with a PVC LB. I wouldn't even venture a guess on how to 'legally' ground a metal LB.
 
When I've had this situation and there was room in the LB, I have tapped the LB and installed a lay-in lug inside. Then just skin the ground and lay it in the lug. I don't know if this is code compliant.
 
Coppersmith said:
When I've had this situation and there was room in the LB, I have tapped the LB and installed a lay-in lug inside. Then just skin the ground and lay it in the lug. I don't know if this is code compliant.
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Even if it’s not code complaint. I would find it to be a safer install, compared to a fault happening and waiting for some one to find out the hard way. Especially a metallic LB in the middle of a non-metallic raceway (pvc underground and rigid riser and than back to pvc somewhere along the way before box termination).

Also I’m sure all of you know form-7 fittings are very tight on cubic inches. I know the cost is probably way more but GUA- fittings have more room and a bonding screw.
 
I assume the OP is talking about the "where conductors terminate or are spliced in a box the equipment grounding conductors shall be connected to the box" rule? Forget what code section that is off the top of my head.

Edit: 250.148
 
You can only splice #6 and smaller in an LB if the volume is stamped in it and box fill calculation is followed.

314.16(b)
314.16(c)(2)

I would drill and tap a metal LB and pigtail a ground screw if the wire was small enough.
 
augie47 said:
Not sure where one would have terminations in a LB (splice occasionally) In any event, if it's a metallic LB and part of a metallic conduit system it would be "grounded" via the conduit system.
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OK, so I am curious about your opinion. I have told my second year students that splice is a termination. in fact, one wire ends and another wire begins, so it is two terminations.

Either way, if you splice, then the code requires the ground to be cut and bonded also, so the OP's question is moot.
 
James L said:
You can only splice #6 and smaller in an LB if the volume is stamped in it and box fill calculation is followed.

314.16(b)
314.16(c)(2)
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Read again, 314 doesn't require the wire to be #6 or smaller. If a 4" conduit fits 8-#3/0 and 1-#6 (it does) then a 200A 3/0 feeder can be spliced in a 4" LB, the way I read it.
 
infinity said:
I agree that it may take some creativity to bond the metal conduit body.
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We routinely drill and tap them for a 10-32 screw on some of our industrial instrumentation circuits where there is a transition from the metal conduit system to a multi-pin cord and plug.
 
Strathead said:
Read again, 314 doesn't require the wire to be #6 or smaller. If a 4" conduit fits 8-#3/0 and 1-#6 (it does) then a 200A 3/0 feeder can be spliced in a 4" LB, the way I read it.
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Not sure where you would get the conductor volume numbers to do the fill calculation for a splice in a conduit body. The rules in 314.16 and 314.28 do not really address the issue of splicing 4 AWG and larger conductors in a conduit body.
 
Strathead said:
Read again, 314 doesn't require the wire to be #6 or smaller. If a 4" conduit fits 8-#3/0 and 1-#6 (it does) then a 200A 3/0 feeder can be spliced in a 4" LB, the way I read it.
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Read again, 314.16(c)(2) says splices have to be in accordance with the chart in 314.16, which only shows up to #6

If it's larger than #6, you can't calculate according to that chart. Therefore it can't be spliced
 
In the past, if I have had to transition from PVC to metal, I just use a box. Much easier to deal with.
 
YoungSinatra said:
If terminations occur in an LB, why is grounding not required? Teacher said everywhere that a connection is made, there has to be a form of grounding but he doesn’t know the answer as to why you don’t need a ground in an LB
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The rule in 250.148 does not include conduit bodies so it does not apply.
However as others have said, a metal conduit body must be connected to an ECG of some type. Typically is it via the metal conduit itself.
 
James L said:
Read again, 314.16(c)(2) says splices have to be in accordance with the chart in 314.16, which only shows up to #6

If it's larger than #6, you can't calculate according to that chart. Therefore it can't be spliced
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Can't be spliced under the rules of 314.16(C)(2). But 314.28 provides a different set of rules for conductors of size #4 and larger, and it covers "conduit bodies used as pull or junction boxes".

Cheers, Wayne
 
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