Multiple Services, 1 Building?

[jds10011]

Apologies if this has been covered somewhere, I suspect I'm not using the correct keywords. Feel free to point me to an old thread.

We'd maxed out the service on a "commercial" building (single-phase, if it matters), and wanted to install another few large current devices. Our boss contacted the local electrician, and he installed a new 200A main panel by feeding a new line to the building from a nearby pole that was feeding a nearby building with much smaller load. (Leaving the existing feed and 200A main panel in place.) I'm convinced everything is safe, but I had always thought code did not allow for multiple services (especially from different transformers) to be brought to one building, especially if the main disconnects are not in the same part of the building. Can anyone clarify?

Thanks!

 

[augie47]

NEC 230.2 has a basic premise that each building can be supplied by only one service. It sounds as if this install might be a violation but you would need to review that section for all the "exceptions" to be sure.

 

[WinZip]

We did a remodel about 6 weeks ago , owner converted 2 units into 1 unit we were aloud to keep the service in each unit but had to label the panels an meter bases at each location , but both were fed from same transformer.


Service 1 of 2

Service 2 of 2

 

[WinZip]

Forgot also the units numbered on each plaque.

Service 1 of 2 units 103-104

Service 2 of 2 units 104-103

 

[John Valdes]

225.30 Number of Supplies.

Where more than one building
or other structure is on the same property and under
single management, each additional building or other structure
that is served by a branch circuit or feeder on the load
side of the service disconnecting means shall be supplied
by only one feeder or branch circuit unless permitted in
225.30(A) through (E). For the purpose of this section, a
multiwire branch circuit shall be considered a single circuit.
(A) Special Conditions. Additional feeders or branch circuits
shall be permitted to supply the following:
(1) Fire pumps
(2) Emergency systems
(3) Legally required standby systems
(4) Optional standby systems
(5) Parallel power production systems
(6) Systems designed for connection to multiple sources of
supply for the purpose of enhanced reliability

 

[new_pe]

A lot of times this is up to the local utility company too, since the service falls into their realm of responsibility. Most utilities as far as I know will not allow multiple separate services to a building. See if your local utility has a set of published rules and regulations. My utility has let multiple services in my experience in the following cases:

1) (2) different voltage systems. 400A delta high leg service existing and we didn't want to have to touch it because the utility won't even do delta services higher than 200A anymore. They allow us to add a separate 208V Y service.

2) Existing 208V Y service was maxed out and a 480V Y service was added for new additional loads.

3) Fire pumps.

4) 480V Y services over normal switchboard sizes can be split up.

5) Multiple services on apartment buildings.