Wire Guage Table For Spa Wiring

[wireman]

Sounds to me like you're spending way to much to GFCI protect it.. A GFCI trips for a reason. They don't nuisance trip unless the GFCI is damaged. As far as testing goes there is no NEC requirement to test your install. Pushing the test button on the GFCI is a good idea but you don't need someone to come out with test equipment.

[Stuart A]

As far as testing goes there is no NEC requirement to test your install. Pushing the test button on the GFCI is a good idea but you don't need someone to come out with test equipment.

In England when any new circuit added is supposed to be tested and inspected and a certificate issued, according to the regs. However a lot of people do not bother doing this.

Chip your joke about the copper made me laugh, very good.

[Chip C.]

Sounds to me like you're spending way to much to GFCI protect it.. A GFCI trips for a reason. They don't nuisance trip unless the GFCI is damaged.

I don't presume to know more than a professional, but must take exception with your statement that GFCIs don't nusiance trip unless they are busted. Highly reactive loads such as electric motors can cause nuisance tripping of GFCI breakers from what I have been told. An aquaintence of mine runs a spa cleaning service, and he tells me that he hears this complaint frequently.

If you think about how an electric motor works, it makes a lot a sense that they not only put a load on, but also produce spurios electrical effects that can apparently "trick" a GFCI/breaker. It is compounded in spas with mixed 240V/120V components on different legs of the same circuit. I think separating out the functions by letting the breaker handle current overload, and using a dedicated GFCI in the disconnet box makes a lot of sense. It is my understanding that a passive/inductive GFCI is much less susceptical to errant tripping in high current applications, especially with mixed voltages like some spas have.

As far as cost is concerned, the Conneticut Electric GFCI disconnect unit compares well. A 50A GFCI breaker runs 80-100 clams, whereas a regular double pole breaker runs only 10-20 clams. Tops, I am spending 20 clams more for a more reliable system, designed specifically for hot tubs. I will forego 2 lunches at Jack-in-the-Box to finance this added expenditure. I guess another question would be, would component makers develop an inductive GFCI disconnect device if there were zero demand for it because errant false tripping did not exist as a problem?

[craighaggart]

Chip, your proposed spa hookup is nearly identical in every way to mine. I have individual #6 copper wires running from dual 50A breakers at the service entrance panel to a Connecticut Electric GFCI spa disconnect (required by code), which is mounted on the back corner of my house within clear sight of the spa (required by code). From there the #6 runs through buried 1.25" nonmetallic conduit to the spa. The total wire run is about 65 feet, and there are no splices. The only break is at the GFCI panel.

My system has been in continuous use for two years now. I've had no problems of any type, and no nuisance trips.

Craig

Sunnyvale, California

[Chip C.]

Craig,

I could say "brilliant minds think alike" but that would sound arrogant. I guess I'm on the right track though!

--Chip

[wireman]

Spurious electrical effects. LOL! What are those.. If your install is safe and makes you happy then it's all good but the fact is that a normal GFCI breaker is fine for a normaly operating hot tub. Electricians are generaly weak on theory, that's a engineers job, but strong on code and installation. To be honest I'm not even sure what you're installing for GFCI protection. Most of us just buy a GFCI disconnect. CH makes a nice one and put it on the wall.

[Chip C.]

Spurious electrical effects. LOL! What are those?

I apologize for using multisyllabic words. Spurious = having a similar characteristics but in a different form. In AC electrical theory, besides the common factors of Ohm's Law that everyone learns in grade school (resistance, voltage, and amperage) there are other spurious effects (related to Hysteresis) to consider such as reactance and impedance. GFCI devices, which were never designed with reactance in mind, sometimes have trouble with these effects, especially in high-current applications where they are amplified.

I am real surprised you never heard of errant GFCI tripping caused by reactive loads. See, an electrical motor is basically a generator in reverse, and does produce a reactive effect of its own on the circuit that can, and sometimes does cause the otherwise good GFCI device to function erratically-- somewhat like a woman with a monthly hormonal imbalance. Having a 240V motor, 240V resistance heater, and 120V UV ozonator on the same circuit is sometimes problematic for a common GFCI/breaker. This is because a GFCI is by design acutely sensitive, and designed to detect infitessimally small deviations from the norm. This is not news.

[craighaggart]

...somewhat like a woman with a monthly hormonal imbalance.

Ah, yes, PMS: Production of Motor Spuriosity !

Craig

Sunnyvale, California

[wireman]

Could you point me to some websites that discuss this? Personally, in the real electrical world, I've never seen nuisance GFCI tripping. Always there is a real problem. Whether it be a defective GFCI or a defective circuit or piece of equipment.

[Stuart A]

Didn't expect to see a spa forum start to go this far in depth in electrical theory.

Anyway in England, before we can be classed as an approved electrician, one of the things we have to do is go to college, which teaches us quite in depth electrical theory. We then have exams on this.

Chip I would always wire a spa on its own dedicated circuit, with its own RCD (GFCI to Americans). You will then have the peace of mind that if you have any nuisance tripping (which you should not get) it will only effect that circuit. Regarding cable selection, in the absence of calculation, always go for a larger size.

On this forum I have only ever noticed people using conduit and single cables, have any of you considered using Steel Wire Armoured (SWA) cables?

[Chip C.]

Chip I would always wire a spa on its own dedicated circuit, ...have any of you considered using Steel Wire Armoured (SWA) cables?

Stuart, I think all of the discussion assumed (correctly) that a spa is always on a dedicated circuit. A self-contained portable spa can have individual components that run on both 240V and 120V in the USA (you don't have 120V in the UK, as I recall). Some jurisdictions do not permit direct burial cable. I have not seen steel-armored wire, but sounds like it falls into that category. PVC conduit is dirt cheap.

[Chip C.]

All done and works perfect. The Connecitut Electric disconnect box has a branch drop for auxillary 110V circuit, so I also added an outdoor electrical outlet while I was at it.

[JonJon]

Contact an electrician. Wire size is more complicated than some chart. The conditions the wire is subject to, the insulation used and the type of conductor all are part of the equation.

If you stick with Copper wire and use number 6/3 with ground [4 wires] for 220 volt 60 Hz AC single phase. For 150 feet from the breaker box you may find that number 4/3 with ground is a better choice due to the resistance build up over that length with number 6/3 with ground. If you get direct burial Cable, you really can't go wrong on the construction of the Cable and its insulation.

[Chip C.]

We used PVC conduit. Sheathed cable is not permitted inside buried condut.

[JonJon]

We used PVC conduit. Sheathed cable is not permitted inside buried conduit.

Good. There is lots of literature available on wiring. The rules are explained in a straight forward manner. Do not try to outsmart the rules even if they seem dumb. Electrickity is nothing to experiment with or do by guess and by gosh. I heard a horror story about a person who wired their house with Bell Wire [a wire is a wire is a wire, right?] and then they could not understand why it did not work [fusible link]. I had a problem one time that blew me away. Every time I flipped on the kitchen lights the breaker tripped. It turned out to be a ground wire too close to the Hot [black] wire feeding the lights in a junction box. [the current load was enough to make it arc, yet not above what the wire was rated at] So proximity can be critical.

[Chip C.]

Electrickity is nothing to experiment with

When I was a teenager, the neighbor lady (a rather large woman) got electrocuted while sitting on the toilet. Her husband had rigged her up a heated toilet seat from old electric blanket parts. Water and electricity can be tricky.

[Greg D.]

...when I say that all the homeowner wiring I've seen is subpar I mean that I wouldn't consider it safe. Not that it is mildly deficient in a few code references but just plain out unsafe.

Would you please post the specifics about these clearly unsafe wiring situations? It's possible that I (and others) might make some of the same mistakes without realizing it. I for one am always interested in learning. Thanks!

Craig

Sunnyvale, California

Craig,

Here's an example of a home owner diy wiring screw up: I was called to my father in law's place to trace the source of water in the basement. It was dripping through the kitchen floor. When I was touching the underisde of the floor while in the basement, my arm was wet and bumped a fluorescent fixture that was turned off and I got a shock. It seems that my brother in law wired that fixture years ago by inturrepting the neutral wire with a switch instead of using the hot wire. The fixture was always energized and when it and I were wet the circuit was completed through me.

Hope this helps,

Greg.

[Chip C.]

Greg, at least your story had an apparent happy ending (you're still here!) unlike the poor lady. For the sins of her husband's failure to follow the National Electrical Code, she indeed paid the ultimate penalty== death in the electric chair.

The moral of the story is that if you play by the rules, you never have to worry about being caught with your pants (or panties) down.

Chip

[Greg D.]

All done and works perfect. The Connecitut Electric disconnect box has a branch drop for auxillary 110V circuit, so I also added an outdoor electrical outlet while I was at it.

Chip,

You did well.

In two states I've installed hot tubs, the local codes required a 120V GFCI outlet with in but outside certain distances from the tub. The assumption is if there is no outlet, morons will drape non GFCI protected extenstion cords near the tub for stuff like radios and TVs.

Greg.

[JonJon]

Can someone tell me how to trace this one down without tearing out all of the sheet rock or using some kind of fancy electronic reflectometer to nail down the distance to the open: I have an intermittent "Open" neutral on one of my dual wall outlets. I have checked all of the "Neutral" wiring in all of the outlets in the vicinity and everything looks and tests out ok [simple three lamp pattern tester]. On the outlet in question the tester starts out with "Open Neutral." Then it mysteriously shifts to "Normal" and devices plugged in suddenly work? Never seen this one.

[JonJon]

Can someone tell me how to trace this one down without tearing out all of the sheet rock or using some kind of fancy electronic reflectometer to nail down the distance to the open: I have an intermittent "Open" neutral on one of my dual wall outlets. I have checked all of the "Neutral" wiring in all of the outlets in the vicinity and everything looks and tests out ok [simple three lamp pattern tester]. On the outlet in question the tester starts out with "Open Neutral." Then it mysteriously shifts to "Normal" and devices plugged in suddenly work? Never seen this one.

[Chip C.]

I can tell you what I would do. I'd start by replacing the duplex outlet-- they're cheap, and if you're lucky, that was the problem and you will be done with it. I've seen this happen before when debris has gotten in an outlet causung an intermittant issue. Might also just be a loose terminal connection.

[Chip C.]

In two states I've installed hot tubs, the local codes required a 120V GFCI outlet with in but outside certain distances from the tub. The assumption is if there is no outlet, morons will drape non GFCI protected extenstion cords near the tub for stuff like radios and TVs.

Greg.

Would that distance be at least 10 ft. away but no more than 2o ft. away?

[JonJon]

I can tell you what I would do. I'd start by replacing the duplex outlet-- they're cheap, and if you're lucky, that was the problem and you will be done with it. I've seen this happen before when debris has gotten in an outlet causing an intermittent issue. Might also just be a loose terminal connection.

Thank you for the input. I will replace the cheap duplex outlet unit and see what I get.