"Ignoramus31846" wrote in message
...
On Wed, 07 Jun 2006 09:39:41 -0500, Bud-- 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


To heat the water faster you would need a higher wattage heater. The
same wattage heaters will draw half the amps at twice the voltage.
Otherwise voltage doesn't matter.

Sure, yes, I would definitely install a new heater instead of the old
one. The old one is rated 4000W at 208 volts (weird rating for a
household heater). Since it is running at 120 volts instead of 208, it
only produces 120*120/208/208*4000 watt or 1,300 watts.

Could the spa handle higher heat production? You would, in effect,
be re-engineering the spa. I personally would be very unlikely to
change parts on a spa given potential safety problems. And if it is
UL listed now it wouldn't be after.

I think that it could, the water flow through the heater is very
substantial. There is also a overheat prevention device on the pipe
that encloses the heater.

i

If you look carefully you may find that your heater element also has a 240
volt rating. It is common for elements to be rated for both 208 and 240
volts.

Don Young