🚀 go-pugleaf

more_da@pts4.pts.mot.com (Dan Morera) writes:
>Greetings and Happy Holidays Netters,
>I am developing a system to remotely control a hot tub, and I have not
>previously worked with the large AC voltages needed to do so.

     Given your discussion, I suggest you get a licensed electrician to
do the job.  You've missed a few key safety issues.

     This is NOT to be taken as a complete list, but first, where you
have water near power, you're usually required to use a GFCI breaker,
and for a hot tub, you definitely should.  Second, you need low-water
and overtemp detectors for the heater to prevent fire should the water
stop flowing or be absent.  Most hot-tub heaters have these built in,
but check.  Redundant overtemp switches are common, and may be required.

     Switches where a wet person can reach them require special handling.
The usual hot tub switch is an air button, a squeeze bulb connected by
a tube to a pressure switch.  Just putting the controls on the +5 supply isn't
good enough, because something might short to the low-voltage portion of
the system.  UL-approved switches for very wet locations exist, but
are expensive.

     And remember, plumbing isn't ground in the era of plastic pipe.

     Have you figured out how much it will cost to heat a hot tub
electrically?  Most people use gas or solar.

     Go with an electrician.

					John Nagle