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Discussion Starter · #1 ·
Hey everybody, im new to this site and would appreciate a little help. I am working on a nuclear densomiter installation and am installing 10 level transmitters on a vertical tree around a vessel. I have two conduit runs going up the tree, one run will carry the AC wires and the other run will carry the discrete and analog wires. The 10 devices will be connected to the rigid conduit via liquid tight flex. I ran my continuous bonding conductor in the AC run, it is connected to the bonding screw in each device, and the other end is connected to the bonding bar in the junction box. I didn't run a ground in the control conduit but now i am being told i have to because the conduit is connected to the devices via flex. I don't really see the need to run a piece of ground through just because it is flex, the ground would essentially be connected to the same screw as the ground from the AC run. I also bonded the control conduit at the junction box. Is this correct?
 

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Hey everybody, im new to this site and would appreciate a little help. I am working on a nuclear densomiter installation and am installing 10 level transmitters on a vertical tree around a vessel. I have two conduit runs going up the tree, one run will carry the AC wires and the other run will carry the discrete and analog wires. The 10 devices will be connected to the rigid conduit via liquid tight flex. I ran my continuous bonding conductor in the AC run, it is connected to the bonding screw in each device, and the other end is connected to the bonding bar in the junction box. I didn't run a ground in the control conduit but now i am being told i have to because the conduit is connected to the devices via flex. I don't really see the need to run a piece of ground through just because it is flex, the ground would essentially be connected to the same screw as the ground from the AC run. I also bonded the control conduit at the junction box. Is this correct?
As always, equipment and devices must be used as intended, and in electrical systems...BONDED" where required. Just because you are wanting to know how dense something is does not change that.
 

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Discussion Starter · #3 ·
Maybe my question is too detailed. The device is bonded via the AC run, i want to know if i have to run a bonding conductor in the discrete/analog conduit as well.
 

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Maybe my question is too detailed. The device is bonded via the AC run, i want to know if i have to run a bonding conductor in the discrete/analog conduit as well.
Typically, if there is something special that a manufacturer would require in order to warranty their equipment they would spell it out. It would not be up to an electrician to determine that...no matter how smart we are.:thumbsup:
 

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Danny,

I see no reason your raceway needs to be bonded other than if it is "likely to become energized".

I would order 2 split collar grounding bushings and bond both ends of ur run and call it good. This method will bond your sealtight. Running a egc would just make parallel paths unless u pulled out the LV wire and put on grounding bushings.
 

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Hey everybody, im new to this site and would appreciate a little help. I am working on a nuclear densomiter installation and am installing 10 level transmitters on a vertical tree around a vessel. I have two conduit runs going up the tree, one run will carry the AC wires and the other run will carry the discrete and analog wires. The 10 devices will be connected to the rigid conduit via liquid tight flex. I ran my continuous bonding conductor in the AC run, it is connected to the bonding screw in each device, and the other end is connected to the bonding bar in the junction box. I didn't run a ground in the control conduit but now i am being told i have to because the conduit is connected to the devices via flex. I don't really see the need to run a piece of ground through just because it is flex, the ground would essentially be connected to the same screw as the ground from the AC run. I also bonded the control conduit at the junction box. Is this correct?
No, you must run a seperate bonding conductor in liquid-tight flexible conduit in accordance with section 10. CEC 12-1306. Just from the JB to the device, in the liquid-tight conduit, not in the rigid conduit feed.

I don't understand why it's such a big deal? Your already pulling control wire in.

It takes just as long to do it correctly, in this case, than incorrectly! :eek:

Borgi
 

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No, you must run a seperate bonding conductor in liquid-tight flexible conduit in accordance with section 10. CEC 12-1306. Just from the JB to the device, in the liquid-tight conduit, not in the rigid conduit feed.

I don't understand why it's such a big deal? Your already pulling control wire in.

It takes just as long to do it correctly, in this case, than incorrectly! :eek:

Borgi
I think the fact that the OP used the word "sealed" seems to be the problem here.
I think you would have had a hold in your work plan before they were poured.
 

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And they are all sealed
Sounds like somebody poured seals before they had done the job properly...

If you've got a conduit system and the end devices are fed with liquid tight you are required to pull a bonding conductor in it as listed in 12-1306, as Borgi mentioned...
 

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is the discrete conduit wires are all low voltage (24vdc) if so i dont think any grounding/bonding is needed, only conduit with wires over 50vac needs grounding of conduit
 

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Sounds like somebody poured seals before they had done the job properly...

If you've got a conduit system and the end devices are fed with liquid tight you are required to pull a bonding conductor in it as listed in 12-1306, as Borgi mentioned...
Even on the low voltage side? If so, why not jumper to a ground bushing on the flex, assuming it's liquid tight flexible metal conduit? The low voltage conduit is already bonded at the JB.

I'm not saying this is the answer, I'm just asking.
 

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Even on the low voltage side? If so, why not jumper to a ground bushing on the flex, assuming it's liquid tight flexible metal conduit? The low voltage conduit is already bonded at the JB.

I'm not saying this is the answer, I'm just asking.
I'm guessing that when the OP said they are sealed he meant in a classified area.. In which case there wouldn't be a ground bushing on the flex, but the connector would thread into the device and I don't think a ground bushing could be installed... I could be wrong as this is just how I'm picturing it..

Quite a few of the inspectors I've seen will check the LT flex for a bonding conductor and if it isn't there they'll write it up.. There are a few exceptions I've seen where they'll allow it... IS (Intrinsically Safe) systems or on Amphenol assemblies where there is no place to attach it, are a couple that come to mind...
 

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is the discrete conduit wires are all low voltage (24vdc) if so i dont think any grounding/bonding is needed, only conduit with wires over 50vac needs grounding of conduit
Where is that in the code? 10-304 lists any metal enclosure for conductors shall be bonded to ground.. 10-400 lists where non current carrying metal parts shall be bonded...
 

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Discussion Starter · #17 ·
You are right that there are no threads sticking out on the flex connectors because one end goes into a t fitting and the other end into an EYS fitting. What everyone seems to be forgetting is that there are 2 ports on these devices, one port has the AC flex run to it and the other port has the analog flex run to it. I ran a ground through the AC conduit which will bond the device, I just don't get why I would have to run another ground through the analog run as it would essentially just terminate at the same point and only serve to provide a parallel path back to the junction box.
 

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You are right that there are no threads sticking out on the flex connectors because one end goes into a t fitting and the other end into an EYS fitting. What everyone seems to be forgetting is that there are 2 ports on these devices, one port has the AC flex run to it and the other port has the analog flex run to it. I ran a ground through the AC conduit which will bond the device, I just don't get why I would have to run another ground through the analog run as it would essentially just terminate at the same point and only serve to provide a parallel path back to the junction box.
You must bond the equipment, which you have done, but you also must bond the conduit carrying your conductors. The CEC requires liquid-tight to have a bond wire ran with the conductors, as it is not a metal conduit. Same as rigid PVC, non-metallic tubing, and other similar raceways. I know it seems unnecessary, but it's required by code, as far as I know. ;)

Hope I am explaining that correctly. Plus it's also good trade practice. Takes little extra time, hurts nothing and gives peace of mind.

On a final note, who is telling you to add the bond wire?

Borgi
 

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Discussion Starter · #19 ·
The consultant at the site I am working at and he doesn't have an electrical background. I don't see the sense in running an insulated ground wire through the flex as it does nothing. The rigid metal part of the conduit run has been bonded at the start of the run, inside the junction box via a ground bushing.
 

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The consultant at the site I am working at and he doesn't have an electrical background. I don't see the sense in running an insulated ground wire through the flex as it does nothing. The rigid metal part of the conduit run has been bonded at the start of the run, inside the junction box via a ground bushing.
Even if you don't see the sense in it, you didn't write the code and how it sits now is not compliant.. What if these devices are changed in the future and no longer require the AC feed and only need the analog? Now you have an ungrounded feed and the next guy has a larger job to do because you didn't build it to code in the first place...

I think you have a couple of options....
1) Challenge the consultant with your code ruling and theory explanation and see what he says... BUT... It might not have a good result, since at the end of the day he is the consultant.
2) Cut the seals, pull a ground wire in and reconnect as needed.
3) Admit to the consultant you missed the ground wire and poured the seals before it could be fixed and see if he has a solution that will work. If he doesn't, suggest if an external ground on those liquid tights is acceptable. If it is I'd suggest loosening the flex, loosen the flex connectors and installing a ground wedge ( https://west.westburne.ca/lug-ground/thomas-betts/3653/ths-3653-t-b-grounding-wedges/product/THS3653 ) between the coupling/seals/fitting and the connector and using a couple stakons and a length of ground wire and some tyraps for each one to fix it. Using the wedges, you won't have to disconnect the flex and bust the seals...

One last piece of advice.. Pick your battles... Is this mistake, whether you agree with it or not, worth going to battle with your consultant? Had it have been built to code in the first place you wouldn't even have to ask the question..

Just my opinion though...
 
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