400A Residential Service

[Charlie R]

First 400a residential service out on my own, 315 ft from the new pole the utility set. We are required to install a meter pedestal for services farther than 200 ft.

Installing 2 200 amp panels

1. Based on NEC 2017 section 225.32 would you consider that meter pedestal a structure. If so it would require a disconnecting means? I have figured 2 emergency disconnects at the building already but the inspector did not give me a straight answer whether he considered that a structure.

2. Grounding - 250.66 gives me #4 GEC based on ungrounded conductors of 4/0 AL (parallel 4/0 from the pole to the meter). The only GEC I have is a UFER at the structure, so I would need to run 315 ft of #4 back to the first disconnecting means if I were required to have disconnects on the meter pedestal.

If the 1st pair of disconnects are not required then my largest ungrounded conductor would be a 300kcmil AL and I would need #2 based on that table. However, 250.66(B) states when connected to a single or multiple concrete-encased electrodes, the grounding electrode conductor can be as small as 4 AWG copper if it doesn't extend to other types of electrodes that require a larger conductor.

My interpretation is that #4 is the answer regardless of conductor size.

Looking for some feedback on this and If I may be missing something

 

[shortcircuit2]

Just pound a couple of ground rods at the pedestal for the GES there.

Use the UFER for the GES at the dwelling structure.

 

[augie47]

You need to pin the inspector (and/or whomever is requiring the pedestal) to see if overcurrent is required there,
Locally, it would not be considered a structure,
If it's meters only, as shortcircuit states ground rods at the meter pedestal and the GES at the structure and no EGC or GEC between the pedestal or structure.
That will change if overcurrent is required at the pedestal.

 

[electrofelon]

Where are you in NY and what utility? I would just do a meter only, service conductors to the house.

 

[VirutalElectrician]

315'? I would consider going to 250 for voltage drop.

 

[Charlie R]

Just confirmed with the inspector, no disconnect needed.

 

[Charlie R]

315'? I would consider going to 250 for voltage drop.

We are running parallel 4/0 to the meter. Then 300kcmil to each panel. Load calc is 95 amps for each panel and based on voltage drop we are around 140 amps. I think that is plenty, considering it is a barndominium and 1 panel is for the garage and the other is the house. Total sqft of the house is 1800, shop sqft is 1200

 

[Charlie R]

Where are you in NY and what utility? I would just do a meter only, service conductors to the house.

It is RGE, going with meter only and service conductor to the house. This project is near Bristol.

 

[electrofelon]

It is RGE, going with meter only and service conductor to the house. This project is near Bristol.

Cool. Note RGE does require rods at the meter even if no disconnect

 

[augie47]

AS for the GEC to the UFER, you are correct, a #4Cu is largest required

 

[gene6]

If I were the customer i'd want a breaker at the meter. It makes future maintenance easier.

 

[Charlie R]

Cool. Note RGE does require rods at the meter even if no disconnect

Yes, no grounding allowed in meter cans.

 

[electrofelon]

Yes, no grounding allowed in meter cans.

No it is required

 

[electrofelon]

For NYSEG, and assuming RGE is the same cuz its basically the same company, note they require a #4, and they also have the "loopback" where it goes thru the rods, then back into the the enclosure.

 

[electrofelon]

again, this is NYSEG, RG&E is probably the same