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.

Voltage does matter. The same heating element will produce 4 times the
power at 240V, compared to 120V, which is exactly what he wants, so the
water heats faster. Many water heating elements are made that are
rated to run at either voltage, they just produce more heat at the
higher voltage.


Could the spa handle higher heat production?

Almost certainly yes. SPAs that heat at 120V take just about forever
to warm up. Even with 4X the heat, it still takes hours. Some small
spas are sold in virtually identical config for 120V or 240V, the only
diff being that 240V goes to the heater.


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.

bud--