I just purchased a new 5-person, 22 jet, 5 HP (no blower) hot tub that
recommends 200 Amp service. I only have 100 Amp service to my house.
Does anyone have any recommendations? The place that sold me the tub
said to get a spa box, but if my household electrical supply can't
handle the load, will a spa box really help?
On 14 Mar 2006 10:45:39 -0800, " email@example.com"
What brand and model spa has a 5 hp motor and needs 200 amps? That
My spa has 2-3hp pump motors (real hp rating, not the bogus spa
rating) and a blower. It has a lot more jets than yours. It runs on
220 volts, and the circuit is 50 amps.
Most spa motors are touted at the hp they develop if you feed them the
maximum voltage they can take without catching fire. Most 3 hp spa
motors are really 1.5 to 2 hp at normal operating voltage. In other
words they rate a 110 volt motor as if you were running it at 180
volts. That makes a 2 hp motor magically rate at 3 hp in the
brochures. I have NEVER seen a production spa with a 5 hp motor.
My best guess is that you misunderstood when the salesman said your
spa is designed to operates on 220 V O L T S.
My best guess is that they recommend a 200 Amp service so that when the
50 amp spa is running, there is some power left for the rest of the
house. With 100amps, it will work, but you you're taking close to half
of the capacity for one appliance. And I agree, 5hp sounds mighty high
for a spa pump.
If you can't live with 50 amps for the rest of the house, or need to
expand the panel for breaker space, etc, then it's time to upgrade the
I agree, run the hottub and turn on the oven and you might trip the main
(even though neither branch exceeds its load). Add in the dryer or A/C and
you will for sure.
Its a shame they don't make conversion kits to run off a 5HP lawn mower
engine. 5 persons and 22 jets sounds like a real wet party, with all that
water in the pipes, starting torque would be quite high.
I love the lawnmower kit idea.
The National Electrical Code has several methods for sizing electrical
services. They take into account what is connected (electric water
heater, etc) and the size of the house. An electrician should do the
calculations to see if your service is large enough before connecting
the hot. Problems (in likely order of current draw) would be electric
electric water heater, electric drier, A/C, electric range. With none of
them I would guess your service would be large enough. You could turn
them off when using the spa but the hot tub may come on periodically to
keep the water hot or run sanitizing cycles.
I am guessing a spa box is a subpanel? Won't make any difference one way or
Possibly the hot tub used enough electricity that the manufacturer makes the
assumption that you will not have enough extra unless you have a 200a
That is a little silly; only by checking out your service can you determine
if you have enough.
Odds are if you have your oven and airconditioner on at the same time it
will trip the main breaker; and if you have it on with nothing else big
going you will be okay.
100a is rather small; if you have a house full of electrical devices you
should be looking to upgrade.
Check inside your hot tub near the computer controller/ eletric pump
area, there should be a small metal plate stamped with the
manufacturers minimum amp breaker requirement...likely 50 amps in your
case. If your 100 Amp breaker box has the room for a 220 volt GCFI
breaker then you should be OK. Most homes under 2.000 square feet have
a 100 amp service panel.
Most important of all you must use a GCFI breaker!!! (Ground Circuit
GCFI breakers are quite expensive (usually $150 or more) , however,
it's mandatory, as this is required by law to prevent electrocution due
to a possible ground fault event. It will trip the breaker at even a
hint of ground fault/leakage.
Also, there should be a separate power/switch box (Spa Box) within 10
feet of the Hot tub so as to be able shut the power-off in an
Check you local city building code for requirements in your area.
NEC is 5 ft min. (as per Tom - point is far enough to avoid contact with
water and electrical). That is generally true for all electrical.
Also readily accessible and in sight of, not necessarily 10 ft.
Appears to not be required for single family dwelling but may? be
required for outside.
There are quite a few requirements for a hot tub which may affect nearby
unrelated wiring or metal that may become energized.
I think the requirement for a nearby disconnect was added after a local
fatality here in NJ. A fat bottom girl drowned during a high school
party at a local health club. The large spa had only one suction
intake on the bottom. She got stuck on it and despite lots of people
trying to pull her loose, they couldn't. The only disconnect was back
at the electrical panel and no one knew how to shut the thing off.
This thing had two flaws, no obvious shut off and having only one main
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