pool bonding / grounding question

I have a question. Pool grounding conductors have to be insulated. That makes sense, if it became energized, that brief energy would not energize anything around the pool. But a pool pump has to be also bonded to the pool rebar, railings, etc. What would keep the railings, etc., from becoming energized if a short occurs ? Thank you.
 

iwire

Moderator
Staff member
Location
Massachusetts
a pool pump has to be also bonded to the pool rebar, railings, etc. What would keep the railings, etc., from becoming energized if a short occurs ?
Nothing, nothing will keep those items from becoming energized during the time it takes the breaker to trip if the pump shorts to ground.

But that is the entire point of the equal potential bonding. All the items connected can be at a potential above normal but they will all be at that same potential so a person cannot get a shock.

In other words if the pump case is 75 volts above normal so will the railings and if you are touching both at the time you would not get a shock.
 
Nothing, nothing will keep those items from becoming energized during the time it takes the breaker to trip if the pump shorts to ground.

But that is the entire point of the equal potential bonding. All the items connected can be at a potential above normal but they will all be at that same potential so a person cannot get a shock.

In other words if the pump case is 75 volts above normal so will the railings and if you are touching both at the time you would not get a shock.
Thank you for explaining that. It just seemed a little odd to me that one conductor is insulated and one is not, even though they both connect to the same fixture. Thank you.
 

FionaZuppa

Senior Member
Location
AZ
Thank you for explaining that. It just seemed a little odd to me that one conductor is insulated and one is not, even though they both connect to the same fixture. Thank you.
its because bonding and egc are very different in nec code. when bonding reaches the pump frame its all essentially one big egc, aka "earth grounded". however, before bonding to pump frame the BC or feeder egc runs in close proximity of the non-grounded conductors. in general, a insulated egc is always safer than non-insulated for all installations, just becomes more $$ to use that way. nec wants the "safer" approach when bodies of water are involved.
 

iwire

Moderator
Staff member
Location
Massachusetts
?? then why does nec call for insulated egc for bodies of water? if its not generally safer then why call for it ?
I have no idea, but it is just as logical for me to say

'Bare EGCs are always safer because the NEC allows bare EGCs'.

Let me ask you this, in a steel framed building with EMT raceways how is an insulated EGC going to increase safety?
 

FionaZuppa

Senior Member
Location
AZ
I have no idea, but it is just as logical for me to say

'Bare EGCs are always safer because the NEC allows bare EGCs'.

Let me ask you this, in a steel framed building with EMT raceways how is an insulated EGC going to increase safety?
with respect to a insulated egc being able to short to a non-grounded conductor, the same as it is for any installation regardless if the bldg is an all metal bonded to egc or not, or whether the raceways used are accepted as the egc, all the same. and given that full EMT still has joints and what not, pulling separate egc is actually safer ;), how much more safer is, i guess, debatable.
 
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