FJRJim Posted March 26, 2007 Report Share Posted March 26, 2007 I am installing a CalSpa CR51, 4 KW heater, two 6 BHP motors, 92x92, 5000 lbs with water, 220V, 50 Amp breaker, 45 amp draw, in conduit, 1/3 run in the garage, 1/3 buried and 1/3 mounted on an exterior wall. 1) The manual says to use 4 gauge THHN wiring over 100 ft (85 ft in 2007 manual) but voltage drop calculators show 45 amps and 6 gauge conservatively rated to 158 feet with a 3% drop. Is the 4 gauge necessary over 100 feet or is CalSpa just being conservative for liability concerns? 2) About half the websites say Handi-spa pads, pavers, gravel, sand, etc, are an acceptable base. The other half say 4" reinforced concrete pad only. CalSpa says concrete only. Is the concrete pad necessary or is CalSpa just being conservative for liability concerns? 3) Has anyone had a negative experience with the Handi-Spa pads? If so, what was underneath the pad? 4) What is the recommended ground wire size for 6 gauge wiring? 4 gauge? Thanks in advance! Jim Quote Link to comment Share on other sites More sharing options...
Dr. Spa Posted March 26, 2007 Report Share Posted March 26, 2007 If you do something to a lower standard than the manufacturer requires, they are well within their right to void your warranty...............It's your call though. Quote Link to comment Share on other sites More sharing options...
Chas Posted March 27, 2007 Report Share Posted March 27, 2007 According to the NEC, you cannot put a 45 amp load on a 50 amp breaker. You are only allowed to draw 80% of the rated load - so 40 amps is the max you can put on a 50 amp breaker. You will need to wire for a 60 amp breaker - that's going to take a lot of wire. Quote Link to comment Share on other sites More sharing options...
whyymee22 Posted March 27, 2007 Report Share Posted March 27, 2007 how far are you running the wire? are you installing a gfi disconnect within 15 feet of spa? Quote Link to comment Share on other sites More sharing options...
FJRJim Posted March 28, 2007 Author Report Share Posted March 28, 2007 Thanks for the replies. 45 amps was what I calculated for a max load, typical should be less. The installation manual specifies a 50 amp breaker. The run is 147' with a GFI disconnect near the spa. Quote Link to comment Share on other sites More sharing options...
FJRJim Posted March 28, 2007 Author Report Share Posted March 28, 2007 I see references to motors pulling up to 10 times the rated amperage for short periods with an accompanying voltage drop. Could this explain the 4 gauge wire requirement? Perhaps extended motor life will pay for the heavier wiring. Quote Link to comment Share on other sites More sharing options...
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