Why do some hot tub manufactures use a 3 wire system and

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aelectricalman

aelectricalman

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Location
KY
Does if follow the same reasons for why water heaters use a 10-2w/g and not a 10-3w/g and a dryer uses 10-3w/g and not a 10-2 w/g? Im trying to explain and my logic is there but i need an easy way to say to a 10 year old.
 
Re: Why do some hot tub manufactures use a 3 wire system and

If an appliance has both line-to-line and line-to-neutral loads, 4-wires will be needed to serve that load. 2-ungrounded, 1 grounded (neutral), and 1 grounding (bonding).

If an appliance has only line-to-line loads, only 3-wires will be needed. The grounded (neutral) conductor can be eliminated.
 
Re: Why do some hot tub manufactures use a 3 wire system and

I understand that, I just don't understand why hottubs arent required to have a 4 wire system. After all there are metal components on the display boards. I guess these manufactures have thought this out, it just seems 4 wire should be required.
 
Re: Why do some hot tub manufactures use a 3 wire system and

They simply have no 120 volt circuits.The heaters,blowers,pumps are all 240.The remaining part of circuitry is derived from a 240 volt transformer to get low voltage in the range of 12 to 24 volts. Very similar to an air conditioner.
 
Re: Why do some hot tub manufactures use a 3 wire system and

I just don't understand why hottubs arent required to have a 4 wire system. After all there are metal components on the display boards. I guess these manufactures have thought this out, it just seems 4 wire should be required
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Ace, what would you do with the extra conductor as it may not be needed. All hot tubs require a separate grounding conductor.

In no case can a hot tub use the neutral to ground metal parts like dryers and ranges where allowed to.

A hot tub with a 3 wire feed is either straight 120 volt, with no 240 volt components

1)Hot

2)Neutral

3)Ground

Or it is straight 240 volt, no components need 120 volt

1)Hot

2)Hot

3)Ground

A 4 wire hot tub would be 240/120, some components use 120 and other components use 240

1)Hot

2)Hot

3)Neutral

4)Ground

A typical water heater is straight 240, no neutral needed

A typical dryer has 240 volt heaters, and 120 volt motor, controls and lamp(s). Because there are both 120 and 240 loads the dryer now gets a 4 wire feed.

i need an easy way to say to a 10 year old.
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Kind of young for a apprentice. :D


Bob
 
Re: Why do some hot tub manufactures use a 3 wire system and

The hot tub may use 3 wire or 4 wire but the most important is the GFCI must have 4 wire for a supply.
 
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