# Secondary Fuel-Source for Generator per Seismic Design Category



## Truck3capt (Aug 3, 2016)

I had a question from our building and zoning department on a project that came through their office.  This may not be the correct place for this and if it isn't I'll move it if need be.  

A local church is looking to replace an old inverter and battery system with a new natural gas fired genset to provide emergency power for their egress lighting and exit signage.  The supplier wants to know if Chapter 13 from the ASCE 2010 Design guide applies and If they need to provide a secondary fuel source in case the underground natural gas was interrupted by a seismic event.  

Our B and Z dept has asked if any of the codes we reference on the fire side have addressed this issue before..  So far I haven't bean able to find anything in the IFC (2006) or NFPA standards we reference to address an alternate fuel source requirement for seismic concerns.  I've never really ran into it but I've only been in our bureau for a little over two years.    Located in central Illinois.  Thanks


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## mtlogcabin (Aug 3, 2016)

The generator has to run for at least 90 minutes, We do not accept natural gas from a utility supplier as meeting that requirement for our seismic zone "D".


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## Truck3capt (Aug 3, 2016)

mtlogcabin said:


> The generator has to run for at least 90 minutes, We do not accept natural gas from a utility supplier as meeting that requirement for our seismic zone "D".



Ok thanks.  Historically we've never required it.  However, I can only think of one application where the occupancy chose natural gas over a diesel fired genset for emergency power requirements.  Are you using the IBC as your basis for requiring it through the ASCE referenced standards?  The only reason I'm asking is because I can't find ASCE Chapter 13-_ Seismic Design Requirements for Nonstructural Components_ listed in the referenced standards in the 2012 IBC. 

If we are looking at requiring something we have typically not enforced I just want to be able to give them a reference.


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## Truck3capt (Aug 3, 2016)

I stand corrected. I found the reference.  Looked right over it.  The NEC looks like it speaks to it also.  Thanks again.


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## steveray (Aug 3, 2016)

NEC speaks to on site fuel for "emergency" generators only If I Recall Correctly....Has anyone really lost nat gas in an earthquake of a non massive scale? (I am sheltered here)


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## Truck3capt (Aug 3, 2016)

steveray said:


> NEC speaks to on site fuel for "emergency" generators only If I Recall Correctly....Has anyone really lost nat gas in an earthquake of a non massive scale? (I am sheltered here)



I think that's a valid question. I think the way our building dept. is going to interpret it is that it's unlikely.  I need to look at the NEC language a little closer, but we've never required it before.   This is a 100 plus year old church.


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## steveray (Aug 3, 2016)

In the NEC "emergency" is mandated by some governing body like DPH for hospitals or shelters or police and fire stations..."Legally required standby" is what the church should be methinks...


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## north star (Aug 3, 2016)

*@ = @ = @*


In looking at the `08 NEC, Article 701 addresses this.
_"Legally required systems are intended to provide electric_
_power to aid in firefighting, rescue operations, control of_
_health hazards, and similar operations."_

The AHJ must specifically designate what is a "Legally
Required Standby System"........The AHJ also must witness
the testing of these type systems when designated and
installed.

Article 701.11(B)(2) requires an "on premises fuel supply
of not less than 2 hours",  ...for an internal combustion
engine as the Prime Mover.

Article 701.11(B)(3) requires that Prime Movers shall not
be dependent upon a public utility gas system for their fuel
supply, nor a municipal water supply for their cooling systems.

IMO, ...that is a lot of requirements for a church to comply
with.



*@ = @ = @*


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## Truck3capt (Aug 4, 2016)

north star said:


> *@ = @ = @*
> 
> 
> In looking at the `08 NEC, Article 701 addresses this.
> ...


Thanks and I would tend to agree and this is where the building department was coming from in their interpretation.


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## linnrg (Aug 4, 2016)

steveray said:


> NEC speaks to on site fuel for "emergency" generators only If I Recall Correctly....Has anyone really lost nat gas in an earthquake of a non massive scale? (I am sheltered here)



Last January a neighboring community had a gas leak that may have been attributed to an earthquake see:

http://www.adn.com/kenai/article/ro...nai-homes-burned-after-earthquake/2016/01/25/

need more facts about the church to agree that a required standby system must be installed.  If it is an option the building owner wants to install and not required why not natural gas.  Many a diesel tank has the goods stolen out of them by people seeking home heating oil when fuel prices skyrocket.  Earthquakes knock tanks off stands and break fuel line connections, etc.  Even so most commercial installations that I see do choose the diesel over natural gas most residential home backups are now choosing the natural gas systems.


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## Truck3capt (Aug 7, 2016)

linnrg said:


> Last January a neighboring community had a gas leak that may have been attributed to an earthquake see:
> 
> http://www.adn.com/kenai/article/ro...nai-homes-burned-after-earthquake/2016/01/25/
> 
> need more facts about the church to agree that a required standby system must be installed.  If it is an option the building owner wants to install and not required why not natural gas.  Many a diesel tank has the goods stolen out of them by people seeking home heating oil when fuel prices skyrocket.  Earthquakes knock tanks off stands and break fuel line connections, etc.  Even so most commercial installations that I see do choose the diesel over natural gas most residential home backups are now choosing the natural gas systems.



The church is 160 years old.  They plan to use natural gas.  The generator is replacing an older battery and inverter system that's becoming unreliable according to the generator supplier.   The generator supplier is out of the St.Louis, MO area.  The New Madrid Fault is in their backyard and we're at the northern edge of the furthest seismic zone that would possibly be affected if St. Louis ever has the big one.

His concern for quoting a system to the church is that we would require the alternate fuel source in addition to the natural gas, most likely a diesel tank with the appropriate seismic bracing and connections.  The cost for that is considerable.  Especially when it's questionable that the 160 year old un-reinforced stone and masonry church would survive long enough after the event to worry about the gas lines failing to the generator anyway.


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