I did find UL has a listing or pool heaters WBRR ( http://productspec.ul.com/details.php?ccn=WBRR ) with mention of leakage detectors.
Now if one installs a heater other than a UL listed WBRR pool heater.(but still a NRTL product in general ) .. ?? why I have ulcers
That was Leakage Current Collector.
Pretty sure that is just the water bond dohicky gizmo.
http://forums.mikeholt.com/showthread.php?t=57988&p=451881#post451881
Thanks. I read too quickly.
but left pondering.. is it a violation to install an electric water heater in a swimming pool circulation system if that heater is not listed for swimming pool use ?