Electrician Talk banner

Ungrounded systems in swimming pools??

2K views 5 replies 6 participants last post by  hardworkingstiff 
#1 ·
After reading some of the posts on grounded and ungrounded systems, it reminded me of an old conversation I remember reading about the push for ungrounded systems (with monitoring) in residential. Something similar they use in hospitals, but not as robust.

Of course this would most likely never happen in the U.S because we are too far set up for grounded systems in our grid.

But it was an interesting concept to see the theory behind it, especially the argument for it in swimming pools (or at least have a sub panel of ungrounded systems). It was suggested that ungrounded systems with monitors be used for swimming pools and close to marinas. They said the alarms would go off immediately when there is a voltage being grounded in the pool and this would be caught sooner rather than later and would possibly save more lives.

The costs involved in installing these ungrounded systems I believe would be too much for some to even consider this concept. But it did have me thinking about it. Most shocks I know of are when someone has been grounded and came in contact with higher voltage potential. Very rare do I hear of a hot to hot or phase to phase shock.

What do you think of this idea of ungrounded systems with monitors for pools?​
 
See less See more
#3 ·
I think it's a good idea and doesn't seem so expensive it would be impractical, when you think of the whole cost of a pool ... so what would you do, feed the pool panel from a transformer with an ungrounded secondary?

If not maybe a shunt trip on the pool panel main rather than an alarm. Or would that really be the same as a GFCI main on the secondary. Would the isolation transformer allow a more sensitive 4-6ma GFCI without nuisance tripping?
 
#4 ·
Interesting...... I suppose a contactor controlled panel, must like we wire gas station islands could be made to GF detection.

Maybe all those pool & Hot tub disco's could be manufactured with this additional alarm feature, much like septic tank alarms we install?

Yet i would imagine they'd all be somewhat more efficient w/ better grounding, not less?:001_huh:

And what about those 3ph pool motors? They exist, not sure if those newfangled SPGFCI's do anything for them???

~CS~
 
#6 ·
With the GFCI protection available today, I don't think an ungrounded system is necessary.

If there was step potential voltage on the earth around the pool, neither an ungrounded system nor properly installed and working GFCI protection would protect someone from the step voltage shock, hence the equipotential bonding grid requirement. The GFCI's would protect everything else just fine.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top