EVDL Administrator wrote:
The EV charger was presumably connected across the 240v line (standard US
setup with a tapped 240v transformer secondary, the tap grounded, and
serving as a return for 120v loads).
The 120v drill charger was in one of the 120v legs. If the breaker in that
leg opened, only 120 volts to ground from the other leg would be available.
Now the EV charger has no return to the full pole transformer secondary, so
it seeks a return to the 120v tap by whatever means it can find. That's
through the drill charger.
Now you effectively have two loads in series across 120v. The high current
EV charger has a lower effective resistance than the low current drill
charger, so virtually all the voltage goes to the drill charger and very
little to the EV charger.
You have it exactly right, David. This is why 240vac breakers *must* be
ganged, so if one leg opens, they *both* open.
--
For every complex problem, there is a solution that is simple, obvious,
and wrong. -- H.L. Mencken
--
Lee A. Hart, http://www.sunrise-ev.com/LeesEVs.htm
_______________________________________________
UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
http://lists.evdl.org/listinfo.cgi/ev-evdl.org
For EV drag racing discussion, please use NEDRA
(http://groups.yahoo.com/group/NEDRA)
