handle ties

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naxet

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Hello ,
I am a journeyman electrician, recently hired in as the electrician for an office complex.I oversee what electrical contractors do at this facility.Question : 30amp 208v receptacle single phase, is it required to have instatanious trip( no handle ties) on this circuit.what I have studied in NEC 2002 I'm not sure. It is clearly stated that 2 circuits feeding 2 recp. on the same yoke must trip simultaniously . thanks for your replies.

[ June 26, 2004, 01:19 PM: Message edited by: naxet ]
 
Re: handle ties

All ungrounded conductors must trip at the same time. A breaker designed for this purpose must be used. I would use a 2 pole 30 Amp breaker and not two single pole breakers with handle ties, because UL did not approve this method and this would be considered a modified installation. A two pole breaker trips internally and externally.
 
Re: handle ties

Thank you ,

That was my thinking, now I need to convince this electrical contractor.
 
Re: handle ties

A couple of things. For some time manufacturers have been assembling 2 or 3 1p breakers together in order to make a multipole breaker. The only thing that you see is that there appears to be a handle tie used to connect the handles together and that the breakers are riveted together. In other words it appears as though it is simply 2 or 3 breakers with a handle tie.
However, what you don't see is a trip bar which has been added internally that connects all breakers together. What this does is trips all poles if one pole calls for a trip. These breakers are labeled as being "common trip." A handle tie can not be relied on to pule the other poles into the open position if one pole trips.
In the field 2 or 3 breakers can be tied together with a handle tie which caused you to turn a group of breakers on and off together it is required such a using a home run circuit where both hot legs land on the same yoke such as feeding a split duple outlet.
Another comment is that these are "thermal magnetic(instantaneous)" breakers and not just instantaneous(magnetic) breakers. This may be knit picking but terminology can be misunderstood by others which can result in a misapplication because there are in fact instantaneous only (magnetic only) breakers available that provide short circuit protection with no overload protection.
 
Re: handle ties

naxet,
It is clearly stated that 2 circuits feeding 2 recp. on the same yoke must trip simultaniously
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This case only requires a common disconnect device and not a common trip device.
30amp 208v receptacle single phase
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If this is only for line to line loads(208v) and not line to neutral loads (120v),then 240.20(B)(3) would again permit the use of a common disconnect (handle ties) device. A common trip is not required for line to line loads. The code only requires common trip device when the circuit serves both line to line and line to neutral loads.
Don
 
Re: handle ties

ditto (what Don said) - if you have a copy of the 2002 NEC Handbook....at 240.20 (overcurrent device required) - there is an extensive commentary with diagrams illustrating the various scenarios/requirements for the 'common disconnect' vs. 'common trip' breaker.
 
Re: handle ties

Originally posted by don_resqcapt19:
naxet,
It is clearly stated that 2 circuits feeding 2 recp. on the same yoke must trip simultaniously
Click to expand...
This case only requires a common disconnect device and not a common trip device.
30amp 208v receptacle single phase
Click to expand...
If this is only for line to line loads(208v) and not line to neutral loads (120v),then 240.20(B)(3) would again permit the use of a common disconnect (handle ties) device. A common trip is not required for line to line loads. The code only requires common trip device when the circuit serves both line to line and line to neutral loads.
Don
Click to expand...
With all due respect to both Don and Dana, I don't interpret this the same. Handle ties are not an option as discussed in 210.4. This is for multi-wire branch circuits with a common yoke (only considered for simultaneous disconnection means). When interpreting 240.20, there must be a line to neutral load when using single pole CB. Must interpret this section in conjunction with 110.3(B), regarding related UL rules. Guys, you can't rely on a handle tie to do all the work in opening a 208V circuit when tripping a fault to ground. The circuit must be effectively interupted internally to eliminate a 120 volt circuit developing as a result of losing one hot leg.
 
Re: handle ties

Originally posted by megawire:
Guys, you can't rely on a handle tie to do all the work in opening a 208V circuit when tripping a fault to ground.
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Your right we can not rely on a handle tie to open all poles on a ground fault but that is not a violation.

The circuit must be effectively interupted internally to eliminate a 120 volt circuit developing as a result of losing one hot leg.
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As surprising as it sounds the code does not say that.

240.20 Ungrounded Conductors.

240.20(B) Circuit Breaker as Overcurrent Device. Circuit breakers shall open all ungrounded conductors of the circuit unless otherwise permitted in 240.20(B)(1), (B)(2), and (B)(3)
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If you only read the above section it sounds like we must use internal common trip breakers for all applications.

Now read this part of the section.


240.20(B)(3) 3-Phase and 2-Phase Systems. For line-to-line loads in 4-wire, 3-phase systems or 5-wire, 2-phase systems having a grounded neutral and no conductor operating at a voltage greater than permitted in 210.6, individual single-pole circuit breakers with approved handle ties shall be permitted as the protection for each ungrounded conductor.
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This clearly tells us that a line to line loads on 3 phase systems can use single pole breakers with approved handle ties.
 
Re: handle ties

240.20(B)(3) 3-Phase and 2-Phase Systems. For line-to-line loads in 4-wire, 3-phase systems or 5-wire, 2-phase systems having a grounded neutral and no conductor operating at a voltage greater than permitted in 210.6, individual single-pole circuit breakers with approved handle ties shall be permitted as the protection for each ungrounded conductor.
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This clearly tells us that a line to line loads on 3 phase systems can use single pole breakers with approved handle ties. [/QB][/QUOTE]

Bob, the above applications contains a grounded neutral. The original post does not. Also, 110.3(B) is the general disclaimer.
 
Re: handle ties

Where is the neutral?

He only said "30amp 208v receptacle single phase"

Yes it could have a neutral but he did not say so.
 
Re: handle ties

megawire,
110.3(B) would only apply to the voltage rating for the breaker, it would not specify if a common trip is required. The common trip issue is a code rule and not a listing rule. Also would you permit the use of fuses on circuits that you say require a common trip?
Don
 
Re: handle ties

what is considered an "approved" handle tie ?
would AHJ determine this.
My problem is , I have electrical contractors using #12 & #10 solid, looped around the handles of (2) single pole breakers.
Just recently when this issue came up (1) of the contractors pointed out HE used a machine screw & tapped the handles.so again ... approved by who?
I don't want to be a hard a** and say "hey , that's not approved " if somewhere it actually is.I also plan on calling the city inspection dept.
It is my OPINION that #12 solid or #10 is a "hack" installation.
 
Re: handle ties

Most times that will mean a handle tie from the breaker manufacturer.

Also I am curious as to what type of circuit they want to use handle ties on.

Not all applications allow handle ties, some circuits require internal common trip breakers which can not be created in the field.
 
Re: handle ties

I don't see a problem using handle ties personally but not a piece of wire... State of Tn will NOT allow handle ties for line to line loads w/o neural but I don't think the code prohibits it...
 
Re: handle ties

Originally posted by necbuff:
I don't see a problem using handle ties personally but not a piece of wire... State of Tn will NOT allow handle ties for line to line loads w/o neural but I don't think the code prohibits it...
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Let me make sure I'm reading this right. IF you have a line to line load that doesn't require a nuetral, you are not allowed to use handle ties??? So, for example, an air conditioner that doesn;t need a nuetral must be fed from individual single pole breakers without handle ties???
 
Re: handle ties

no. you would have to use a 2 pole breaker.. not 2 single pole breakers w/ a handle tie. Tn prohibits this.
 
Re: handle ties

Originally posted by necbuff:
no. you would have to use a 2 pole breaker.. not 2 single pole breakers w/ a handle tie. Tn prohibits this.
Click to expand...
That makes more sense, but in reality, isn't a twp-pole breaker basically just two single poles with a handle tie across them? :D
 
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