Cornfused

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jxofaltrds

jxofaltrds

Inspector Mike®
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Mike P. Columbus Ohio
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ESI, PI, RBO
Example:

I install a 20-amp circuit for my whirlpool.

It is a Jacuzzi brand.

From Jacuzzi:
"Depending on the model of the whirlpool bath, the installation/operation manual specifies which units must be 15 amp versus 20 amp GFCI protected. Since the model number or name of the unit was not listed in this email, you'll need to look at the specifications sheet to determine which is needed for your installation. It is clearly stated at the bottom of the page on each spec sheet. If we require a 15 amp set up, we certainly do not want the unit installed on a 20 amp breaker and yes, putting a 15 amp required unit on a 20 amp service can cause issues with the unit."

If this is protected (the circuit) with a 20-amp breaker, is this a code violation?

Mike P.
 
Re: Cornfused

"yes, putting a 15 amp required unit on a 20 amp service can cause issues with the unit."

What if those 'issues' means a fire?

Sounds like you should heed Dave's post (websparky).

Pierre
 
Re: Cornfused

I think that it is important to remember that from a strict code stance, 110.3(B) applies only to the listing information, and not neccassarily all of the literature suplied by the manufacturer.

I can't think that a 20 amp breaker would be in excess of the maximum overcurrent protective device to protect the motor, so I can't see a violation (assuming that it is a properly wired circuit). I would assume that the manufacturer is simply stating the minimums that they are comfortable with.
 
Re: Cornfused

From Jacuzzi's web site;
Electrical Connection RapidHeat
Before installing electrical connection, inspect the heater nameplate and determine if you have a 120 VAC or a 240 VAC unit (240 VAC unit not available in U.S.A.). Install a separate 120 VAC 15 AMP or 240 VAC 15 AMP dedicated circuit with GFCI protection. With a #8 solid copper wire, bond the heater to the house electrical panel or approved local bond. A bonding lug is provided on the heater.
Click to expand...
 
Re: Cornfused

Originally posted by ryan_618:
I can't think that a 20 amp breaker would be in excess of the maximum overcurrent protective device to protect the motor, so I can't see a violation (assuming that it is a properly wired circuit). I would assume that the manufacturer is simply stating the minimums that they are comfortable with.
Click to expand...
OK if 15 is the minimum would you be comfortable with me using an existing 50 amp range feed, properly wired of course. :)

[ February 28, 2004, 01:55 PM: Message edited by: iwire ]
 
Re: Cornfused

Originally posted by iwire:

We do not know what size wires are used in the unit or the ratings of the controls, I would use the size they say. :)
Click to expand...
Bob: Do these small motors offer their own overload protection?

I'm wondering if you provide short circuit and ground fault protection in the form of the breaker, and the motor offers overload protection, have you satisfied the overcurrent protection requirements?
 
Re: Cornfused

Deleted, new computer error. I bought a Gateway 350 lap top, belch and it posts. :eek:

[ February 28, 2004, 02:24 PM: Message edited by: bennie ]
 
Re: Cornfused

The 15 amp is to dump the motor in a locked rotor event. A 20 amp would cause winding damage.
 
Re: Cornfused

Ryan for us to treat this like you suggest wouldn't they have to provide both pieces of information as required by 430.7(D)(1)?

Minimum supply circuit conductor ampacity, and the maximum ampere rating of the circuit short-circuit and ground-fault protective device.
 
Re: Cornfused

Hi Bob. I don't think 430.7(D)(1) applies, simply because I don't believe it is a multimotor or combination load equipment.

When I read 430.6(A)(1), I read it as saying that the breaker is supplying ground-fault and short-circuit protection, but not neccassarily overload protection. I think this satisfies the requirement that you bring up on 430.7(D)(1), if indeed the section I cite applies.

Art. 430 has always been a tricky article for me, so I don't claim to know what I'm talking about here. I am interested to see where this thread goes.
 
Re: Cornfused

The short and ground fault being referenced is in the motor, not in the wiring to the motor.

A stalled motor is a short circuit with a degree of impedance. This impedance will delay the trip of the branch circuit breaker.

A ground fault in the motor winding will also have impedance and may not trip an oversized breaker.

Should a stalled or faulted motor remain in that state for a period of time, the branch circuit will overheat. The overload relay will often be welded closed.

Should the branch breaker be too large, the trip time will be increased causing excessive temperature in the winding, and the wiring.

The running overload, starting current, locked rotor current, and winding to ground fault, all have too be considered for any protection of the circuit.

A locked rotor event will usually become a shorted turn hot spot. Motor is toast. Motor, hopefully, will be shut off before this happens.
 
Re: Cornfused

I thought(please no laughing)that a motor had to have an overload protection in it per 430.

Is this correct?

Some info: http://www.ul.com/motor/news.html

If I had a washing machine that stated a 15 amp circuit required, would you make me run a seperate 15 amp for it?

A Kenmore gas cook top requires a 15 amp recpt. Does that mean I that I would have to install a duplex if it was on the small appliance circuit?

Where I am going is, where does the inspectors authority or responsibility end.

Anyone see where I am going and can explain it better please do so.

Mike P.
 
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