Multi-wire circuits: no handle ties

[Joe Funderburk, CMI]

Do you write that up as a defect? Example: dishwasher and garbage disposal share the same grounded (neutral) conductor. This is a common wiring practice

If you don't, I'd recommend it. Here's the hazard: you need to change the garbage disposal. You flip its breaker off. You're working on the neutral conductor and someone turns on the dishwasher. The neutral is now a current carrying conductor. Ouch! Begin to curse wife!

Photo below: 2 lower breakers serve 2 kitchen appliances. One neutral.

[Jim Port]

Prior to the 08 NEC there was no requirement for a handle tie on MWBCs unless in commercial settings or on the same yoke. This is now required whenever MWBCs are used along with the conductors of the MWBC to be grouped together in the panel.

[Jim Port]

I forgot to add in my other post that the neutral was required to be pigtailed. You could not use the device to splice the neutral in the MWBC.

[Jeffrey R. Wicklander]

Won't mention anything about it unless the house was built while the jurisdiction was under 2008 code.

Jeff

[Mark E. Northrup]

Joe I was wondering how you know that they are sharing a neutral. From the pic i see a red wire and a black wire. but cannot see how they share a neutral. Thanks
Mark

[Jeffrey R. Wicklander]

If romex was run, it would be pretty simple to tell. Two hots in the jacket along with a single neutral coming out of the panel. If it was run in pipe, they may be the only three wires running in the pipe.

Jeff

[Joe Funderburk, CMI]

Originally Posted by mnorthrup

Joe I was wondering how you know that they are sharing a neutral. From the pic i see a red wire and a black wire. but cannot see how they share a neutral. Thanks
Mark

Count the 15/20 amp breakers and count the neutrals. They should be equal in number. In this case, there was one more breaker than there were neutrals. A scan of the incoming wires revealed that this one was a 3 conductor + ground.

[Joe Funderburk, CMI]

Originally Posted by jwicklander

Won't mention anything about it unless the house was built while the jurisdiction was under 2008 code.

Jeff

I wrote it up as a recommended upgrade. It's a safety hazard, same as the lack of a GFCI, no matter the age of the home.

[Jeffrey R. Wicklander]

I don't consider it a safety hazard. It's a very commonly applied and accepted work practice.

Jeff

[Joe Funderburk, CMI]

Originally Posted by jwicklander

I don't consider it a safety hazard.

Jeff

So, then, what is the purpose of the handle tie in today's code?

[Jeffrey R. Wicklander]

The NEC is starting to become a babysitting service because of the unqualified personnel that think they know how to work on electrical. Do you recommend every client to upgrade all their receptacles to be tamper proof as required?

Jeff

[Bruce A. King]

Originally Posted by jfunderburk

So, then, what is the purpose of the handle tie in today's code?

The handle ties are needed on 240V loads so that both breaker sections trip if the load is excessive on just one leg.

The disposal and d/w are just 120V loads so there is no reason to trip both breakers if one draws too much.


As far as I know, the situation in the original post is considered acceptable since "only electricians should be working with the wiring".

I was installing a ceiling fan once and the power company guy came to turn off the power to the house so I was just working away and got fried because of two reasons. He turned it back on within 10 minutes without coming back to the door to warn me even after I told him what I was doing and voltage was still at the fixture with the switch off to a crappy wiring technique called "switched neutrals".

Maybe someone has the code history on switched neutrals (thread drift here), I don't think they are allowed anymore but once were allowed.

[Joe Funderburk, CMI]

Only electricians install garbage disposals?

[Mark E. Northrup]

Originally Posted by jfunderburk

Only electricians install garbage disposals?

If that was the case i would be out of work. And home depot would not sell disposals.
I agree with you on the neutral though. It would be a safety concern.

[Bruce A. King]

Anyone can install one, just some get shocked in the process.

I have to admit, I never thought of that scenario.

I did a reinspect once where they still had not tightened a panel lug, the builder called the electrician and the owner of this fairly large company was in the area so he came right over to fix it. I watched this guy, he probably had 30 years experience, he turned off the main breaker and pulled out a big allen wrench (non insulated type) and started to tighten the lug and stopped. He put the tool in his pocket and walked about 60 feet to the truck and came back with a voltmeter and made sure the power was off and then proceeded. I was thinking, yep, he has seen some weird wiring problems and was not ready to take a chance that day.