695-3(C)(2)

[don_resqcapt19]

If I have a feeder supplied fire pump in a campus type installation, would it be permitted to have a diesel engine fire pump as the backup in lieu of alternate electrical power source for the electric fire pump?

 

[letgomywago]

If I have a feeder supplied fire pump in a campus type installation, would it be permitted to have a diesel engine fire pump as the backup in lieu of alternate electrical power source for the electric fire pump?

Maybe if you can convince someone that's the intent but that section requires an on-site power production facility so what is power is it all mechanical or does it need to be electrical power?

Obviously a cogen facility or a fuel cell meets this and a diesel generator could so why not skip the losses of the generator and motor.

Have you asked the fire martial already.

 

[Dennis Alwon]

I would think so based on this section

695.3(B) Multiple Sources.

If reliable power cannot be obtained from a source described in 695.3(A), power shall be supplied by one of the following: [20:9.3.2]
(1) Individual Sources.

An approved combination of two or more of the sources from 695.3(A).
(2) Individual Source and On-site Standby Generator.

An approved combination of one or more of the sources in 695.3(A) and an on-site standby generator complying with 695.3(D). [20:9.3.4]

Exception to 695.3(B)(1) and (B)(2): An alternate source of power shall not be required where a back-up engine-driven fire pump, back-up steam turbine-driven fire pump, or back-up electric motor-driven fire pump with an independent power source in accordance with 695.3(A) or (C) is installed.

ENHANCED CONTENT
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If none of the power supply sources specified in 695.3(A)(1) through (A)(3) can individually provide reliable power with adequate capacity, 695.3(B) permits an approved combination (two or more) of those sources or a combination of one or more of those sources with an on-site standby generator.
In lieu of installing an on-site standby generator, an engineor steam turbine–driven fire pump can be provided as backup for an electric fire pump. In that instance, the electric fire pump is permitted to be supplied by only a single power source. This allowance provides some design options for augmenting an electric fire pump that is supplied by an unreliable source.

 

[letgomywago]

I would think so based on this section

Yep right there is says engine driven

 

[don_resqcapt19]

I would think so based on this section

I skipped over that, however that exception is only to 695.3(B)(1) and (B)(2), and my installation will be covered by 695.3(C).

This project is an upgrade in capacity from the original 1965 installation. The original design is based on the diesel pump providing backup for the electric pump, but in the original installation, they sized each of the pumps at 1/2 the required fire water flow. Each pump is rated at 1500 GPM. The project will replace both the electric and diesel pumps with 3000 GPM pumps.

It is my opinion that the diesel driven pump complies with the intent of the "alternate power source" required by 695.3(C), but does not comply with the actual code language.

 

[wwhitney]

I skipped over that, however that exception is only to 695.3(B)(1) and (B)(2), and my installation will be covered by 695.3(C).

Sorry, don't you have a choice of 695.3(B) or 695.3(C)? 695.3(C) doesn't have any mandatory language, it uses the "shall be permitted" terminology. So complying with 695.3(B) Exception would suffice.

Cheers, Wayne

 

[don_resqcapt19]

Sorry, don't you have a choice of 695.3(B) or 695.3(C)? 695.3(C) doesn't have any mandatory language, it uses the "shall be permitted" terminology. So complying with 695.3(B) Exception would suffice.

Cheers, Wayne

The plant distribution system does not permit options (A) or (B) as the sources in (A) are "not practicable and the installation is part of a multibuilding campus-style complex", and (B) requires one of the sources in (A).

That is the very reason (C) exists and the reason for the "shall be permitted" language. It acts as an exception to (A).

 

[wwhitney]

The plant distribution system does not permit options (A) or (B) as the sources

So because of the design of the existing plant electrical distribution, it's not practicable to provide one of the sources in (A)?

(B) covers the case that "reliable power cannot be obtained from a source described in 695.3(A)." That could arise because the sources in (A) are not reliable, or because the sources in (A) are not available. (B)(1) and (B)(2) still require a source from (A). But the Exception to (B)(1) and B(2) just says that "An alternate source of power shall not be required where a back-up engine-driven . . ."

Since the language requiring one or both of the sources to be from (A) exists only in (B)(1) and (B)(2), and not (B) parent, one can read the Exception to (B)(1) and (B)(2) as not requiring that the power source come from (A). I.e. that the exception means "any power source plus a back-up engine driven . . ." Not 100% clear to me--seems like the Exception would be better written as (B)(3) and then it could either say "an approved combination of one of the sources in (A) and a backup engine driven . . ." or "any source plus a backup engine driven . . ."

Also, checking NFPA 20 to see if it provides further clarity may be useful.

Cheers, Wayne

 

[don_resqcapt19]

So because of the design of the existing plant electrical distribution, it's not practicable to provide one of the sources in (A)?

(B) covers the case that "reliable power cannot be obtained from a source described in 695.3(A)." That could arise because the sources in (A) are not reliable, or because the sources in (A) are not available. (B)(1) and (B)(2) still require a source from (A). But the Exception to (B)(1) and B(2) just says that "An alternate source of power shall not be required where a back-up engine-driven . . ."

Since the language requiring one or both of the sources to be from (A) exists only in (B)(1) and (B)(2), and not (B) parent, one can read the Exception to (B)(1) and (B)(2) as not requiring that the power source come from (A). I.e. that the exception means "any power source plus a back-up engine driven . . ." Not 100% clear to me--seems like the Exception would be better written as (B)(3) and then it could either say "an approved combination of one of the sources in (A) and a backup engine driven . . ." or "any source plus a backup engine driven . . ."

Also, checking NFPA 20 to see if it provides further clarity may be useful.

Cheers, Wayne

Nothing in (A) is available ....5 kV service with the service equipment being a pole mounted gang switch with fused cutouts. Even if the utility would permit a second gang operated fusible pole switch, that would require about a half mile of 5 kV power distribution to get to the pump house.

The only option is (C) and this installation is the exact purpose of (C). It is just that the letter of the language does not appear to permit an engine driven pump as the backup for (C).

I see no way to read the exception they way you want to read it.

This will be pushed up to the AHJ which, in this case is very likely the fire insurance underwriter.

 

[letgomywago]

Nothing in (A) is available ....5 kV service with the service equipment being a pole mounted gang switch with fused cutouts. Even if the utility would permit a second gang operated fusible pole switch, that would require about a half mile of 5 kV power distribution to get to the pump house.

The only option is (C) and this installation is the exact purpose of (C). It is just that the letter of the language does not appear to permit an engine driven pump as the backup for (C).

I see no way to read the exception they way you want to read it.

This will be pushed up to the AHJ which, in this case is very likely the fire insurance underwriter.

This will eventually end up on someone's desk who's butt is on the line. I'd say let them make the call