detached fourplex property

[bobbymari]

So , we have a four unit bldg all bldgs detached from one another. Our meter section will be on rear bldg, all units fed underground. Question is this being that all units are detached would we treat each individual sub as its own "service" as far as grounding. I/e driving a rod for each detached unit tied in with each cold water entry and bond the neutral bar. Units power all originates at rear bldg with an egc along with their subfeeds.
Or do we treat it like a typical subfeed with isolated neutral bar

 

[bobbymari]

Or would it just simply get its own grounding electrode system at each detached unit ..ground rod tied in to cold water entry and leave neutral isolated to avoid parallel path of neutral return

 

[Sierrasparky]

I think this is what you are looking for. :

250.32 Buildings or Structures Supplied by a Feeder(s)

or Branch Circuit(s).
(A) Grounding Electrode. Building(s) or structure(s)
supplied by feeder(s) or branch circuit(s) shall have a
grounding electrode or grounding electrode system
installed in accordance with Part III of Article 250. The
grounding electrode conductor(s) shall be connected in
accordance with 250.32(B) or (C). Where there is no
existing grounding electrode, the grounding electrode(s)
required in 250.50 shall be installed.

 

[bobbymari]

I think this is what you are looking for. :

250.32 Buildings or Structures Supplied by a Feeder(s)

or Branch Circuit(s).
(A) Grounding Electrode. Building(s) or structure(s)
supplied by feeder(s) or branch circuit(s) shall have a
grounding electrode or grounding electrode system
installed in accordance with Part III of Article 250. The
grounding electrode conductor(s) shall be connected in
accordance with 250.32(B) or (C). Where there is no
existing grounding electrode, the grounding electrode(s)
required in 250.50 shall be installed.

Thank you sir.
Equipment ground ran with feeders, ges at each detached bldg with isolated neutrals...

 

[GoldDigger]

As long as there is a service disconnect ahead of the wire runs to each building, they are feeders. If there are only meters and no disconnect with OCPD, then they are still service conductors.

 

[bobbymari]

As long as there is a service disconnect ahead of the wire runs to each building, they are feeders. If there are only meters and no disconnect with OCPD, then they are still service conductors.

Yes ocpd ahead of feeds to detached units. Thanks

 

[mgookin]

So , we have a four unit bldg all bldgs detached from one another. Our meter section will be on rear bldg, all units fed underground. Question is this being that all units are detached would we treat each individual sub as its own "service" as far as grounding. I/e driving a rod for each detached unit tied in with each cold water entry and bond the neutral bar. Units power all originates at rear bldg with an egc along with their subfeeds.
Or do we treat it like a typical subfeed with isolated neutral bar

Sounds to me like you have 4 - one unit buildings.

Am I reading that wrong?

 

[kwired]

As long as there is a service disconnect ahead of the wire runs to each building, they are feeders. If there are only meters and no disconnect with OCPD, then they are still service conductors.

That is the key here - where is service disconnecting means?

Each separate building needs it's own grounding electrode system either way - it just connects to the grounded conductor if they are service supplied vs to the equipment grounding conductor if they are feeder supplied. Each separate building also needs, at or on the building, a disconnect (or up to six disconnects) regardless if service or feeder supplied. 2014 NEC did relax the rules on whether a feeder supplied disconnecting means needs to be suitable for use as service equipment though.

 

[bobbymari]

That is the key here - where is service disconnecting means?

Each separate building needs it's own grounding electrode system either way - it just connects to the grounded conductor if they are service supplied vs to the equipment grounding conductor if they are feeder supplied. Each separate building also needs, at or on the building, a disconnect (or up to six disconnects) regardless if service or feeder supplied. 2014 NEC did relax the rules on whether a feeder supplied disconnecting means needs to be suitable for use as service equipment though.

Got it, yes each unit will be fed from main multimeter section behind rear building with ocp so yes they will each be feeders not service and feeders will contain egc from the main service panel so we will be providing each unit with a grounding electrode system but isolating the neutrals at the subs so as not to have floating neutrals back to the gear..
Thank you all