I have 3 pool pumps operating on individual 220 circuits. Each pump is
grounded with an 6 AWG bare copper wire to metal structures of the pool
from the bonding lugs on pumps. All wire is carried in metal conduit.
Each pump has two hot lines (black and red) coming from the main
breaker panel. The pumps are all connected to a single ground (Green)
which is grounded (attached) to the box containing the pump switches.
For additional safety I wish to replace each pumps 2 pole breakers with
2 pole GFIC breakers. Because I do not have a neutral and I understand
that the ground and neutral bars are connected in the main, I assume
that to make the breakers function properly I must route the ground
(Green) through the GFIC breaker where the neutral line would attach
and attach the pigtail on the breaker to the neutral bar in the main
breaker box. Is this correct? If this is the case I will need to
detach the ground from the switch box and pull a ground to the main
breaker box? Should a pull three separate grounds, one for each pump,
or can I use a single ground that is spliced in the main breaker box so
I can route the ground to each of the breakers?
The groundING conductor (green or bare) is bonded to the ground bus in
the panel - regardless of whether the circuit is protected by an "ordinary"
overcurrent protection breaker, a GFCI breaker, or an AFCI breaker.
A GFCI breaker (or an AFCI breaker) will have a neutral conductor from it
that must be attached to the neutral bus in the panel.
Both hots from the circuit's cable attach to the hot terminals on the
breaker, and since there is no neutral conductor for the circuit, there is
nothing to attach to the neutral terminal on the breaker.
It is only the hots and the neutral (groundED) conductors that must pass
through the GFCI breaker. The ground (groundING) conductor has nothing
different to its installation than any other situation.
GFCI protection works on detecting any current that does not return through
its intended path. With a single pole breaker, this means measuring the
current through the hot and the neutral to detect a difference. With a two
pole breaker, current in one hot must return through either the other hot,
or the neutral, or split between the two. GFCI protection involves measuring
all three to make sure everything works out even.
"I really think Canada should get over to Iraq as quickly as possible"
Thanks! The GFIC breakers work fine on two of the pumps.
The third pump circuit (220vac) is on a timer and which controls the
pump and an ionizer (120 vac). The ionizer and the circulation pump
should be running simultaneously. The the ionizer is plugged into an
outlet which gets its power from one of the hot leads (120), coming the
timer that also goes to the pump. The neutral to the 120 ioinizer
outlet is from another circuit in the box. When the ionizer is plugged
in and on the GFIC breaker trips. If the ionizer is not pluged in the
GFIC breaker works fine. The ioinizer and pump work fine under this
set up when the non-GFIC breaker is in place. The ionizer and the
circulation pump should be running simultaneously thus both need to be
triggered by the timer. Any ideas of how to solve this problem?
There are 2 types of 240V GFCI. One is for applications that only
require 240V and have no neutral. The other is for applications that
use both 240V and 120V and use a neutral.
As was pointed out, these all work by comparing current going out and
coming back. In the case of the ionizer, the current through it is not
coming back to the GFCI, so it will always trip. You need a 240V GFCI
with neutral protection and to route the neutral from the ionizer
through it. Since the ionizer is tied to some other neutral, if that
neutral has anything other load on it, you will need to get the ionizer
on to it's own neutral. Or, equivalently, have whatever supplies any
other loads on the ionizer neutral pull its hot from one of the hots on
the same GFCI. The second approach would then provide GFCI protection
for the other loads as well.
That last sentence is the key to the problem.
Any load current that flows through the GFCI in any way must return through
it as well. If the outlet is powered by a hot that comes from a GFCI, it
must use a neutral that goes back to that same GFCI, and not directly to
the neutral bus (or to a different GFCI).
By the way, generally speaking, code doesn't usually allow one two pole
breaker to supply both 120 volt loads and 240 volt loads as described.
Yes, in a clothes dryer and electric range, there tend to be both loads,
but supplying different devices where some are 120 and others are 240 is
generally frowned upon.
That said, exceptions are sometimes made. We have a cold storage room
that has a 3-wire feed from a two-pole breaker. 240 volts is needed for
a small (300 watt) baseboard heater that provides a tiny heat source
should the temperature in the winter drop below freezing. The room has
a light and one outlet, and each of these are powered off of opposite
hots on the feed. The inspector did not have a problem with this, probably
because of its light use -- the light probably draws more energy in a year
than anything else on that circuit.
"I really think Canada should get over to Iraq as quickly as possible"
I'm no expert on electric code, but exactly are you referring to when
you say code usually doesn't allow a two pole 240V breaker to supply
both 240V and 120V loads.? Just like the OP, my spa has both 240V and
120V loads. The heater is 240V, the blower, pump, light are 120V. The
spa is UL listed, so it's hard to imagine this is somehow prohibited by
code. Plus, you point out that it's routinely done for some other
appliances too. So, how can it be prohibited by code?
When an appliance has but one attachment plug, the power is supplied
through two hots and a neutral in the one plug. Internally, the
appliance splits the power as needed. The issue that the Code has with
using a 240 volt circuit to feed a 120 volt receptical is that
typically, the 240 volt circuit is supplied by a circuit breaker rated
at more than 20 amps, usually a 30 or 50 amp 2-pole breaker. By
installing the 15 or 20 amp receptical on this 30 or 50 amp circuit,
you are in violation right there. In the case of the exception for the
storage room that was cited in another post, a single 300 watt heater,
a light and one outlet can get by on a 15 or 20 amp circuit, so that is
probably the basis for the exception.
Because you are dealing with a swimming pool, grounding and bonding are
very important and are not always as simple as they appear. A frank
discussion with your local electrical inspector and/ or electrician
would not be a bad thing.
If you wanto to learn more about the whys and wherefores, take a look
at this link:
You have 220 volt and ground. You have no need for a neutral, so try to get
double pole GFCI's without them. They used to make them, but I'm not sure
they still do. Check the instructions, as there may be no need to connect
the neutral wire, as your not using a neutral
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