Posted By: newsgraphics
Pool - Daisy chained GFCI - 05/18/19 04:37 AM
Hello everyone. We're in the process of having a pool installed and recently had PVC conduit run from the service entrance on one side of the house (an all-in-one one exterior panel) through the front yard to power the pool pump and related equipment on the opposite side of the house. This 6awg 240v circuit will be fed with a new 50 amp breaker at the main panel, and will power a pool subpanel with individual GFCI breakers at the pool equipment location. The pool company's electrician was to put in a standard breaker at the main panel, but I am concerned that one day someone might accidentally cut into the underground PVC conduit (buried 24 inches) when installing sprinkler lines or the like and hit a live wire. As such, I'm having them put in a GFCI main panel breaker to protect the underground circuit even though it exceeds code requirements. Can I expect that this daisy chained setup will cause any trouble as far as false trips, etc., or is it one of those "try it and find out" kinds of things? Thanks for your input.
Posted By: HotLine1
Re: Pool - Daisy chained GFCI - 05/18/19 04:43 PM
Protecting the feeder to the pool equipment subpanel with a GF breaker at the source should not cause any 'false trips' unless there is a fault within the feeder.
That said, in the event there is a GF on any of the branch circuits from the pool subpanel, depending upon the sensitivity of the 50 amp GF breaker, it may trip with or before the branch circuit CB. That's dependent on the sensitivity curves of the breakers, and really 'deep' electrical theory.
Greg may have some input.....
Posted By: gfretwell
Re: Pool - Daisy chained GFCI - 05/18/19 05:30 PM
There is no problem daisy chaining GFCIs, I do it all the time with the cord mounted GFCI I use when I am working outside. The circuit has or is supposed to have a GFCI but I still like having one I monitor and test regularly. There is also a GFCI on my boat lift in addition to the GFCI feeding the circuit.
This is a very mature technology and I am skeptical of any claims of false trips unless the GFCI itself is bad. That is usually a hard failure. (won't reset, even with the downstream circuit disconnected).
You are right, it is beyond the code requirement but it should work fine.
Posted By: JoeTestingEngr
Re: Pool - Daisy chained GFCI - 05/28/19 12:20 AM
There should be no problem as long as you don't mind the possibility of the breaker in your house being the 1st or maybe only breaker to trip, on a fault out by your pool. It's not like you can coordinate ground trip sensitivities and time delays, like you can in AC SWGR lineups.
Posted By: newsgraphics
Re: Pool - Daisy chained GFCI - 05/28/19 10:15 AM
Thanks all for your input. It looks like we are going to have to keep a standard breaker in place. This application requires a 60 amp breaker and Square D stupidly does not make 60 amp GFCI breakers for Homeline panels (only for QO panels.) I tried searching for a UL classified breaker of this flavor but was unsuccessful. What I may do, although it's not my preferred solution due to double-breakering, is to have a separate 1-circuit load center/disconnect mounted beneath the main panel (where the underground conduit enters) to accommodate the GFCI breaker. (Or, I may just make peace with it as-is, as it is technically up to code, even though I'd argue this is an area where the code falls short.)