ECN Forum Forums General Topics of the Trade General Discussion Area Duplex service question

What is the normal way you would wire a duplex service? Come down with a common riser into a trough then out of the trough to the two meters then down to the panels, or a separate riser for both then of course separate meters and panels for both??? This is a upgrade from 100 amps to 200amp service.
Of course I understand that if I use one common riser, it will have to be calculated to serve the two appartments. Thanks for the input. Also I'm sure this would be considered one service, so the standard two ground rods should be sufficient, right???

Sparky, I would use a duplex meter enclosure and a single riser.

See page 18 of the link below.

http://www.milbankmfg.com/Products/Catalogs/CatalogFiles/PDF/N&SC%2006%2005.pdf

Roger

On multi family jobs it sometimes requires a third meter for the commons circuits, depends on the laws in your area, not everywhere is the same. Just something to check, we had duplex upgrades here, when we upgraded we had to seperate the circuits, and add the third meter.

Thanks for the info...yes the milbank can for 2 meters seems the way to go. LK, there is no common circuits between the apartments. Each apartment only has at this time, a main, range and 4 circuit fuse panel.
The only thing I will be adding will be a 10KW heat/unit under the crawl space and a 2 ton A/C unit outside. It looks like they have electric water heater, maybe electric range, don't know for sure since there is a gas meter outside??? Thanks for the help.. Steve..

Steve:
What LK (Les) is saying by "Common Area", may be called a "Owner/Landlord/House" meter and panel. This would serve the 'common' heat plant (IF only one furnace for both tenants) a 'common' laundry facility in the basement; basement and stairway lighting, and smoke detectors.

This is required to prevent loss of power in the event one of the tenants moves or fails to pay the elec bill and the 'common' area items are connected to that tenants meter.

Here in NJ, a 'multi-family' with a 'common area' requires a 'house' meter and panel. IF there are NO common area, and each unit is independent, NO 'house' meter is required.

The HVAC equip you are wiring, is there a unit for each tenant, or one unit for the both tenants??

Anyone have an idea what one of the duplex meter bases cost?? Just in the general area?? My supply houses are closed and I've got to come up with a price tonight if possible. Thanks..
Hot line, I think we were both typing at the same time. No, there is going to be a heat and a/c unit for each apartment and no common breeze way lights or the such. Thanks again..

Sq D catalog (best I can do now) is $302 for 2 meter, 200 amp main, 100 amp each meter

"Anyone have an idea what one of the duplex meter bases cost??"


They're expensive. Around here we just use two meter combos side by side for overhead. One rigid riser to support the drop and one smaller EMT riser for the second. The POCO splices them together at the weatherhead as long as they are no more than 18 inches apart. I can buy two 100 amp combos, the riser, the extra 1" EMT riser and weatherhead, the extra #4cu,& the extra hub for under $200.