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#41132 - 08/16/04 04:04 AM Gensets & Nat. Gas
George Corron Offline
Member

Registered: 05/16/01
Posts: 728
Loc: Lorton, Va USA
We had this discussion a while back. This happens all the time with contractors around here, among other issues. FYI, I have 3 schools that have Natural Gas generators on this line.

Schools in this area are used as emergency shelters. The remnants of Hurricane Charley passed through over the weekend,,,, HMMMMM,

What would have happened if the storm had taken a slightly different track and we would have needed these schools as shelter.

SOL

Natural Gas Service Still Out for 3,000 Customers
Updated: Sunday, Aug. 15, 2004 - 11:48 PM

HAYMARKET, Va. - It now looks like it'll be at least Tuesday before all the customers who lost natural gas service in the Haymarket area of Prince William County will have it restored.
Nearly three-thousand homes and businesses were without gas service after a construction crew damaged a 12-inch main Saturday afternoon.

Washington Gas spokesman Tim Sargeant says crews have started to restore service to about 700 customers. That involves going door-to-door, restoring service at the meter, and re-igniting pilot lights.

Sargeant says if a customer isn't there when the crew comes, a business card will be left. He advises that no one should try to restart the gas service themselves.

The area affected is roughly bordered to the north by the Route 15 corridor, along Waterfall Road, and to the south by the Somerset Crossing community and Route 29.

Sargeant says service to the southern portion of that area may be restored Sunday morning, but the rest of the customers will likely have to wait at least through the day.

Heating is not a problem this time of year, but residents may not have hot water or a working stove as a result of the break.

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#41133 - 08/16/04 12:05 PM Re: Gensets & Nat. Gas
e57 Offline
Member

Registered: 05/27/03
Posts: 2837
Loc: S.F.,CA USA
Had someone ask about a NG Generator a while back, as they remembered being without power after our last big quake, for several weeks!

My reply was... Diesel! The first thing you're going to do after a big quake is shut off the gas, if it doesn't shut off itself via the "quake valves" that are being installed now. If the quake was big enough to knock out the electric, the little metal ball in your gas valve will definately drop.

If a legally required stand-by:

"701.11(3) Dual Fuel Supplies.
Prime movers shall not be solely dependent on a public utility gas system for their fuel supply or municipal water supply for their cooling systems. Means shall be provided for automatically transferring one fuel supply to another where dual fuel supplies are used."
_________________________
Mark Heller
"Well - I oughta....." -Jackie Gleason

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#41134 - 08/16/04 01:18 PM Re: Gensets & Nat. Gas
Ron Offline
Member

Registered: 03/13/02
Posts: 577
Loc: White Plains, NY
If it is a Level 1 (defined by NFPA and AHJ), then you need on-site storage too.
NFPA 110
5.1 Energy Sources.
5.1.1* The following energy sources shall be permitted to be used for the emergency power supply (EPS):
(1)* Liquid petroleum products at atmospheric pressure
(2) Liquefied petroleum gas (liquid or vapor withdrawal)
(3) Natural or synthetic gas
Exception: For Level 1 installations in locations where the probability of interruption of off-site fuel supplies is high, on-site storage of an alternate energy source sufficient to allow full output of the emergency power supply system (EPSS) to be delivered for the class specified shall be required, with the provision for automatic transfer from the primary energy source to the alternate energy source.
_________________________
Ron

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#41135 - 08/16/04 03:17 PM Re: Gensets & Nat. Gas
iwire Offline
Moderator

Registered: 01/05/03
Posts: 4343
Loc: North Attleboro, MA USA
In MA natural gas is the predominant prime mover for smaller article 700 loads.

In June I traveled through CT, NY, RI, NY and NJ connecting Article 700 Gen Sets to off site monitoring and out of the approx 100 sites I visited everyone was Natural gas.

Typically the diesel sets we install are for optional standby loads or very large article 700 loads.

Bob
_________________________
Bob Badger
Construction & Maintenance Electrician
Massachusetts

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#41136 - 08/16/04 03:34 PM Re: Gensets & Nat. Gas
Ron Offline
Member

Registered: 03/13/02
Posts: 577
Loc: White Plains, NY
Bob,
For the 100 or so gens that you worked on recently, were they designed by the same firm or standard set of contract document for a chain store? I find that many of our clients that have always done it a certain way need a bit of arm twisting to consider another way.
_________________________
Ron

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#41137 - 08/16/04 03:47 PM Re: Gensets & Nat. Gas
Roger Offline
Member

Registered: 05/18/02
Posts: 1779
Loc: N.C.
Has anyone here installed a NG/Diesel dual fuel unit yet?

Big bucks!!!

Roger

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#41138 - 08/16/04 04:07 PM Re: Gensets & Nat. Gas
iwire Offline
Moderator

Registered: 01/05/03
Posts: 4343
Loc: North Attleboro, MA USA
Ron, yes and no.

All are now owned by the same chain, however they where built by at least 3 different chains with vastly different designs and times of construction, say from the 60s to present.

It is a sure bet different engineers.

When I first got in the trade I thought gen sets where the way to go for emergency egress lighting, now with some time in if it was up to me I would go with Bodine type ballasts.

Having one emergency genset for all the egress lighting IMO is almost as bad as relying on the Natural Gas. As you are well aware gensets can fail to start or transfer for a lot of reasons.

The large black out last year (and the non start of many of these gen sets) was the push this chain needed to have us connect the Gensets to the chains central monitoring station.

They watch for:

1)Gen Run to verify successful weekly exercise.

2)Gen Fail

3)Power Fail at ATS normal Terminals.

I was both happy and surprised that they spent the money for this.

Bob
_________________________
Bob Badger
Construction & Maintenance Electrician
Massachusetts

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#41139 - 08/16/04 04:17 PM Re: Gensets & Nat. Gas
Ron Offline
Member

Registered: 03/13/02
Posts: 577
Loc: White Plains, NY
I am also a big proponent of battery backed up emergency and egress lighting (Bodine or one of the others). I have trouble with lack of maintenance of the batteries per NFPA 101 Life Safety Code. Even some of the newer self test units, get ignored when they fail.
Most if not all sites I work on have 702 type generator needs for the entire building, so to utilize them for 700 and 701 loads are easy (although I have trouble with many of my associates/EC keeping 700 and 702 load separated). I prefer to have both battery and genset backup for emergency and egress lighting, as one will fail at some point. The folks I deal with are more likely to be nervous if the genset is not maintained well, as opposed to the battery lighting, because the 702 loads are their "cash cows".
_________________________
Ron

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#41140 - 08/16/04 04:35 PM Re: Gensets & Nat. Gas
iwire Offline
Moderator

Registered: 01/05/03
Posts: 4343
Loc: North Attleboro, MA USA
 Quote:
The folks I deal with are more likely to be nervous if the gen set is not maintained well, as opposed to the battery lighting, because the 702 loads are their "cash cows".


Sad how that works, but if you can take advantage of it great.

The customers we have that have cash cow 702 Loads would not think of letting us put article 700 loads on their gen sets.

That is a real shame as these Gen sets are typically grossly over sized which causes problems with the diesel engines.

Nice talking with you.

Bob
_________________________
Bob Badger
Construction & Maintenance Electrician
Massachusetts

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#41141 - 08/16/04 05:54 PM Re: Gensets & Nat. Gas
SolarPowered Offline
Member

Registered: 07/05/04
Posts: 615
Loc: Palo Alto, CA, USA
I just heard on the radio that it will still be two more weeks before power is restored in some areas of Florida. No mention was made of the status of NG in those areas.

It's interesting reading between the lines in what George said and what Bob said. My take on what Bob said is that typically what happens in practice is a discussion something like: "Well, let's see, we're required to have backup power. Section 700 says '...'. AHJ says that NG is OK. So, let's put in a NG generator." In other words, the old "What is the minimum code requirement?" approach. As George points out, if you're really serious about being prepared for reasonably-foreseeable disasters, NG by itself just doesn't cut it--you've got to have a local source of energy. In Florida right now, it looks like a three-week local fuel supply would have been a really good idea.


[This message has been edited by SolarPowered (edited 08-16-2004).]

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