Office furniture system 8 wire whip

[hhsting]

Attached sketch I have 208V/120V three phase system at Panel A. Panel A circuit A-29 has 2 poles circuit breaker and circuit A-28 has 2 poles circuit breaker.

I have plans that show whip 8 wire furniture system wiring schematic as shown on attached sketch which shows 6 receptacles for 6 cubicals fed from circuit A-28 phase A and neutral N and 6 receptacles 6 cubicals from A-29 from phase B and same neutral N. A-28 has wire 2#12 + 1#12G and A-29 has wire 2#12+1#12G total of six wires.

I am not sure if the schematic is wired correctly but have following questions:

1. Would I need handle ties multiwire branch circuit A-28 and A-29 per code?

2. Should not all 12 cubical receptacles be wired from 2 pole breaker circuit A-28 to avoid handle ties?

3. The wires going to furniture from Panel A are six wires. Should not the wires be 3#12+1#12G for A-28 and 3#12+1#12G for A-29 to make it 8 wires?

 

[infinity]

If I remember correctly a typical 8 wire setup has A-B-C-N-EGC (5 wires) and H-N-EGC 3 wires.

 

[hhsting]

So that would be one three poles breaker and one single pole breaker from Panel A?

 

[infinity]

Yes if you were using all 4 circuits.

 

[MyCleveland]

hh
Furniture service can be 8W set up like discussed with a 3cct group (shared N) + 1cct group giving you the 8W.
It can also be as you described with 2cct (shared N) + 2cct (shared N) giving you another way to have a 8W.
This is typically used in buildings where the office floors are served with 120/240V-1P.
What you are describing though is served via only 2 ccts. When this is not coordinated the EC is then forced to combine the two hots off the furniture together to energize both internally wired ccts in the furniture base.
Sounds like designers did not work through this issue with the furniture vendor and just put down a 6W service. Loading on the furniture will dictate if this was a good decision.