When providing branch circuits for pre-wired furniture partitions (8-wire system) the 2005 NEC requires all power to be disconnected simutionasuly, I was told I cannont use 4 breakers with tie-handles across them as the devices are not listed for this use. Is this true? I have done this in the past without a problem and have never gotten any negetive feedback or been told that the devices are not listed for this use? and if they are not how would you install 8-wire furniture??
Tie-Handles
- Thread starter Mike01
- Start date
- Status
Both 605.6 and .7 requires simultaneous disconnect of multi-wire BC
"Multiwire branch circuits supplying power to permanently connected freestanding partitions shall be provided with a means to disconnect simultaneously all ungrounded conductors at the panelboard where the branch circuit originates."
I'm not sure you need to gang four circuits???
"Multiwire branch circuits supplying power to permanently connected freestanding partitions shall be provided with a means to disconnect simultaneously all ungrounded conductors at the panelboard where the branch circuit originates."
I'm not sure you need to gang four circuits???
Mike01 said:
maybe but you should read the def first
Branch Circuit, Multiwire. A branch circuit that consists of two or more ungrounded conductors that have a voltage between them, and a grounded conductor that has equal voltage between it and each ungrounded conductor of the circuit and that is connected to the neutral or grounded conductor of the system.
- Location
- Massachusetts
RUWired said:
If it is an 3 + 1 circuit (one 3 phase multiwire sharing a neutral and a two wire circuit with it's own neutral) he does not have to join the single circuit to the multiwire circuit breakers together.
In some cases the multiwire and two wire circuits even come from different panels.
chris kennedy
Senior Member
- Location
- Miami Fla.
- Occupation
- 60 yr old tool twisting electrician
Mike01, aren't these whips 3 phase condutors, 3 neutrals and 2 EGC's? If its the same prefab cubes I see, It's a listed assembly with no multiwire on a single yoke. I've done lots of these with each cir. on a single pole 20 and never had an inspector want a single disco for an entire office.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Mike01 said:
Mike--- I am not sure where it says that all power must be disconnected simulataneously from the partitions. However if it does require simultaneous disco you could use a 4 pole contactor to disconnect the unit.
If the unit comes with a male plug would that not count as the disco. See attached Hubbell PDF.
https://www.hubbellnet.com/connexion/brochures/furn_feed.pdf
I have never seen these units so I may be way off base here.
- Location
- Massachusetts
I don't believe a contactor can be used as a disconnecting means for this purpose.
As far as the connection an 8 wire whip will be hardwired.....unless you have an 8 pole plug. $$
As far as the connection an 8 wire whip will be hardwired.....unless you have an 8 pole plug. $$
- Location
- New Jersey
- Occupation
- Journeyman Electrician
We're currently installing some 8 wire furniture systems. It's an AMP system that has three circuits sharing one over sized neutral, one circuit with it's own neutral, an EGC and an IG.
Even if the furniture system had separate neutrals for each circuit you could still choose to supply it with a MWBC. The only part of the setup that requires a handle tie is the MWBC. Circuits with separate neutrals do not require handle ties.
Even if the furniture system had separate neutrals for each circuit you could still choose to supply it with a MWBC. The only part of the setup that requires a handle tie is the MWBC. Circuits with separate neutrals do not require handle ties.
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