Concrete encase meant for fire pump feeders

[Paul Emond]

I am doing a job in Los Angeles. It is a 7 story mixed use project with a 3 level parking deck below ground. The plans call for both rigid conduit and concrete encase meant for the fire pump feeder. This seems like overkill. I always thought it was one or the other, not both.

 

[raider1]

Welcome to the forum.

Check out 695.6(A)(2)(d).

(2) Feeders. Fire pump supply conductors on the load side
of the final disconnecting means and overcurrent device(s)
permitted by 695.4(B), or conductors that connect directly
to an on-site standby generator, shall comply with all of the
following:
(a) Independent Routing. The conductors shall be kept
entirely independent of all other wiring.
(b) Associated Fire Pump Loads. The conductors shall
supply only loads that are directly associated with the fire
pump system.
(c) Protection from Potential Damage. The conductors
shall be protected from potential damage by fire, structural
failure, or operational accident.
(d) Inside of a Building. Where routed through a building,
the conductors shall be installed using one of the following
methods:
(1) Be encased in a minimum 50 mm (2 in.) of concrete
(2) Be protected by a fire-rated assembly listed to achieve
a minimum fire rating of 2 hours and dedicated to the
fire pump circuit(s)
(3) Be a listed electrical circuit protective system with a
minimum 2-hour fire rating

Chris

 

[texie]

I am doing a job in Los Angeles. It is a 7 story mixed use project with a 3 level parking deck below ground. The plans call for both rigid conduit and concrete encase meant for the fire pump feeder. This seems like overkill. I always thought it was one or the other, not both.

As raider1 mentioned, 695.6 would apply here whether they are feeders or, as is often the case, service conductors as it is less complicated in many cases as opposed to a feeder.
The NEC would not require rigid conduit but maybe that is just the way the engineer wants it or a local code issue. Note that in 695.6 for feeders there are other ways to comply other than concrete encasement, but may not be very attractive in many cases due to cost and complexity.

 

[Paul Emond]

Satisfied with your input.

Satisfied with your input.

Thank you both. This is my first time on here as a registered participant.
i appreciate your input. Pretty much what I was thinking, that it is being required by the engineer for his own reasons. Bottom line is: build it according to plan unless the inspector and the engineer (in writing) agree to an alternate method.