I have a very old spa.

It has a 120V circuit for everything, the pump and heater.

I had to do some repair on it yesterday. The heater was not heating,
which, as I realized, was caused by a crimp that worked itself
loose. Which I recrimped.

It seems to work, but still, the low power heater is very slow to heat
the spa at 120V.

The heater is switched on and off with a power relay (contactor).

The question that I have is this. Would it be sensible to add another
circuit to this spa, supplying 240VAC, that would power the heater
only. The old control system and pump would still be on 120VAC, but
the contactor would switch 240VAC going to the heater.

I would use a GFCI breaker on that 240V line, just like I have on the
120V line.

The only issue that I have with this possible change is that instead
of one breaker disconnecting the spa, there are now two. It may
present a possible hazard to someone attempting to repair the spa, as
they could turn off one circuit and forget to turn off another,
leading to possible electric shock.

Any thoughts?

i

Oh, and I realize that I would need a bigger contactor. No problem
here.

i

On Wed, 07 Jun 2006 13:18:18 GMT, Ignoramus31846 wrote:
I have a very old spa.

It has a 120V circuit for everything, the pump and heater.

I had to do some repair on it yesterday. The heater was not heating,
which, as I realized, was caused by a crimp that worked itself
loose. Which I recrimped.

It seems to work, but still, the low power heater is very slow to heat
the spa at 120V.

The heater is switched on and off with a power relay (contactor).

The question that I have is this. Would it be sensible to add another
circuit to this spa, supplying 240VAC, that would power the heater
only. The old control system and pump would still be on 120VAC, but
the contactor would switch 240VAC going to the heater.

I would use a GFCI breaker on that 240V line, just like I have on the
120V line.

The only issue that I have with this possible change is that instead
of one breaker disconnecting the spa, there are now two. It may
present a possible hazard to someone attempting to repair the spa, as
they could turn off one circuit and forget to turn off another,
leading to possible electric shock.

Any thoughts?

i

Ignoramus31846 wrote:
Oh, and I realize that I would need a bigger contactor. No problem
here.

i

On Wed, 07 Jun 2006 13:18:18 GMT, Ignoramus31846 wrote:
I have a very old spa.

It has a 120V circuit for everything, the pump and heater.

I had to do some repair on it yesterday. The heater was not heating,
which, as I realized, was caused by a crimp that worked itself
loose. Which I recrimped.

It seems to work, but still, the low power heater is very slow to heat
the spa at 120V.

The heater is switched on and off with a power relay (contactor).

The question that I have is this. Would it be sensible to add another
circuit to this spa, supplying 240VAC, that would power the heater
only. The old control system and pump would still be on 120VAC, but
the contactor would switch 240VAC going to the heater.

I would use a GFCI breaker on that 240V line, just like I have on the
120V line.

The only issue that I have with this possible change is that instead
of one breaker disconnecting the spa, there are now two. It may
present a possible hazard to someone attempting to repair the spa, as
they could turn off one circuit and forget to turn off another,
leading to possible electric shock.

Any thoughts?

i




It's hard to recommend doing this without seeing it, knowing your skill
levels, etc. Essentially, you are modifying a std power pack, which
is likely UL listed, and turning it into something else. Another
problem is if say a future owner or even you calls a service guy, who
now has a kludge to deal with and may not service it.

If you do do it, I would install a 240V GFCI that becomes the single
breaker for the whole SPA. You can then use 240V off that for the
heater, 120V off that for the rest of the SPA. That's how my spa is
set up. Also make sure that all metal bonding of the spa is maintained.

On 7 Jun 2006 07:25:18 -0700, wrote:

Ignoramus31846 wrote:
Oh, and I realize that I would need a bigger contactor. No problem
here.

i

On Wed, 07 Jun 2006 13:18:18 GMT, Ignoramus31846 wrote:
I have a very old spa.

It has a 120V circuit for everything, the pump and heater.

I had to do some repair on it yesterday. The heater was not heating,
which, as I realized, was caused by a crimp that worked itself
loose. Which I recrimped.

It seems to work, but still, the low power heater is very slow to heat
the spa at 120V.

The heater is switched on and off with a power relay (contactor).

The question that I have is this. Would it be sensible to add another
circuit to this spa, supplying 240VAC, that would power the heater
only. The old control system and pump would still be on 120VAC, but
the contactor would switch 240VAC going to the heater.

I would use a GFCI breaker on that 240V line, just like I have on the
120V line.

The only issue that I have with this possible change is that instead
of one breaker disconnecting the spa, there are now two. It may
present a possible hazard to someone attempting to repair the spa, as
they could turn off one circuit and forget to turn off another,
leading to possible electric shock.

Any thoughts?

i




It's hard to recommend doing this without seeing it, knowing your skill
levels, etc. Essentially, you are modifying a std power pack, which
is likely UL listed, and turning it into something else. Another
problem is if say a future owner or even you calls a service guy, who
now has a kludge to deal with and may not service it.

If you do do it, I would install a 240V GFCI that becomes the single
breaker for the whole SPA. You can then use 240V off that for the
heater, 120V off that for the rest of the SPA. That's how my spa is
set up. Also make sure that all metal bonding of the spa is maintained.


Here's where I am confused. How do 240V GFCI breakers work? By
comparing currents going through two legs? If so, how can I power 120V
devices, that would naturally give off some current to neutral, and
yet not trip the GFCI?

i

Ignoramus31846 wrote:

Here's where I am confused. How do 240V GFCI breakers work? By
comparing currents going through two legs? If so, how can I power 120V
devices, that would naturally give off some current to neutral, and
yet not trip the GFCI?




There are two types of 240V GFCI. One only checks the current flow
between the two hots. It will trip if you try to use it with a neutral
and pull 120V off one leg. The other type includes neutral protection
and compares all the current flow. That's the one you want.