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Posted By: George Corron Gensets & Nat. Gas - 08/16/04 11:04 AM
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.
Posted By: e57 Re: Gensets & Nat. Gas - 08/16/04 07:05 PM
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."
Posted By: Ron Re: Gensets & Nat. Gas - 08/16/04 08:18 PM
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.
Posted By: iwire Re: Gensets & Nat. Gas - 08/16/04 10:17 PM
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
Posted By: Ron Re: Gensets & Nat. Gas - 08/16/04 10:34 PM
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.
Posted By: Roger Re: Gensets & Nat. Gas - 08/16/04 10:47 PM
Has anyone here installed a NG/Diesel dual fuel unit yet?

Big bucks!!!

Roger
Posted By: iwire Re: Gensets & Nat. Gas - 08/16/04 11:07 PM
Ron, yes and no. [Linked Image]

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. [Linked Image]

Bob
Posted By: Ron Re: Gensets & Nat. Gas - 08/16/04 11:17 PM
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".
Posted By: iwire Re: Gensets & Nat. Gas - 08/16/04 11:35 PM
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. [Linked Image]

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

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

Nice talking with you.

Bob
Posted By: SolarPowered Re: Gensets & Nat. Gas - 08/17/04 12:54 AM
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).]
Posted By: e57 Re: Gensets & Nat. Gas - 08/17/04 02:41 AM
"Has anyone here installed a NG/Diesel dual fuel unit yet?
Big bucks!!!"

There is such an animale????
$$$$$$ I imagine so........

My thinking on it is totally seperate deisel, or LP/NG dual fuel.

On the lighting issue, we just did a job with LV DC lighting, and remote battery packs in a seperate room. Maintenance should be real easy.... Walk into the room, all lights green = good, flip a switch, all lights red, and walk around for 90 minutes looking at the lights. Otherwise repair or replace. Other than the lights themselves, all in one room. $900 ea, + install + mark up!

As for gennies, some ought to come with green holstien patterns.
Posted By: George Corron Re: Gensets & Nat. Gas - 08/17/04 02:53 AM
Lemme repeat what I've said in other threads on the topic, and for anyone watching the news lately on FL.

Ya ever notice, after a disaster, there ALWAYS seem to be these guys in these green trucks with green baggy clothes? They nearly always have #2 diesel with them.

Gimme oil

Next thing is... Gens are only as good as your maintenance program, which includes regular, monitored, exercise. Leaving a NG genset to fend for itself with automatic exercise and it will fail you. Diesel is a lubricant and prone to less of these such failures.

[This message has been edited by George Corron (edited 08-16-2004).]
Posted By: Bjarney Re: Gensets & Nat. Gas - 08/17/04 04:05 AM
 
Spleen venting... I always hated—
24V engine-control and 480V {voltmeter/freqmeter} wiring mixed on control-panel doors and every lead white.
Day tanks, pumps and assorted controls and alarms
480Y stators where the installer “forgot” the neutral connection,
or adding a neutral-ground connection when building had resistance-grounded service
Teardown from rotor-diode failures causing/caused by armature problems
Never a simple, reliable welding-connector disconnect on start-battery leads
All-too-short 480V crankcase-heater life versus 208V
Very expensive but still sleazy transfer-switch controls
Maddening noise during engine runs that cut though all forms of hearing protection
Sniveling building personnel regardless of scheduled test date,
but screaming bloody murder in a start failure




[This message has been edited by Bjarney (edited 08-17-2004).]
Posted By: iwire Re: Gensets & Nat. Gas - 08/17/04 10:03 AM
Bjarney
Quote
24V engine-control and 480V {voltmeter/freqmeter} wiring mixed on control-panel doors and every lead white.
Day tanks, pumps and assorted controls and alarms............Very expensive but still sleazy transfer-switch controls

Oh yeah I see you have been there too.

With about 100 sites and 170 Gen-sets to connect remote monitoring to we got to see a lot of different brands, age, and voltage of both the gen-sets and the ATS.

It would be very easy if you are not careful to get messed up. All the wiring as you said would look the same, a lot of 16 AWG tapped of off the line terminals with no OCP. Some of the older ATS switches used 49 volts as the internal control wiring.

We needed to have 12 VDC, 24, 120, 240, 277 and 480 VAC relays with us to make sure we were ready for anything.

George I am not advocating Natural gas over Diesel just pointing out how it is in other areas. For better or worse it is an accepted practice in this area .

I still would prefer battery units for lighting or both as Ron stated. A diesel generator even as reliable as they are is still only one source, if it fails as many did during the last big black out your left with nothing. [Linked Image]

Maintenance is without a doubt the biggest problem with any of the methods.

Storage of fuel on site also has it's problems, the day tank of a gen-set in an upper floor mechanical room twice overfilled and flooded the offices below with fuel oil. We got involved after the second flood as the building owners where not happy with the original installers.

We have also had to change a gen-set from Diesel to Natural Gas because of a wetlands issue.

No easy answers, I did see a fluorescent lamp that would glow for hours after power is removed, it works even if it hits the floor and breaks. That could be the next generation egress lighting. [Linked Image]

Another long post, sorry [Linked Image]

Bob
Posted By: fla sparkey Re: Gensets & Nat. Gas - 08/18/04 02:13 AM
I live in the area of Florida that was hit by hurricane Charley. On my way home from work today my boss had me check on a genset that was recently installed by our company on a large house. When their area lost power it kicked in and did it's job-for 30 hours. It was a propane fueled unit and ran out of fuel on Sunday, leaving the homeowners in the dark again. It had a 125 gallon propane tank. My boss recommended geting a larger fuel tank. The homeowners still lost their food. How are you going to get propane fuel delivered on a Sunday after a hurricane? Diesel was available at the stations long after they sold out of gas.
Posted By: iwire Re: Gensets & Nat. Gas - 08/18/04 08:40 AM
fla sparkey That is very true, but that type of generator is not an emergency generator (Article 700) to the NEC.

This would be an optional standby unit (Article 702), as such fuel choice and amount of run time is entirely up to the people paying the bill. [Linked Image]

If you are involved with selling a genset you could certainly let the customer know about the availability of diesel over propane.

The NEC is not concerned with keeping refrigerators running. [Linked Image]

Even if this was an 'emergency' generator the NEC only requires 2 hours worth of fuel on site.

Bob
Posted By: GamecockEE Re: Gensets & Nat. Gas - 08/18/04 01:19 PM
In reading the different posts, I get the impression that some of you are using gen sets as your only source of back-up power for emergency (700) systems. 700.12 says that these systems must be on-line in 10 seconds after a power failure to supply the load. It seems that battery systems and/or UPS still need to be used to carry through to successful gen set start-up (if that occurs). After all most transfer switchs delay some period of time just to make sure that the power is truly off and that the utility recloser has locked out and then the generator must come on-line successfully before being allowed to assume a load.

Having gone through Hugo and a little bit of Charlie (without power this time for two days) the odds based on historical data say that a catastrophic strike of that magnitude (Hugo, Andrew, Charlie) may only happen once in a fifty or hundred year period to a particular area. From an economic viewpoint it's hard to justify the outlay of money to put in an infinite amount of fuel supply or foresee all the possible scenarios that may occur. In these parts of South Carolina, the hospitals got priority in getting fuel and getting the utility power back on.

[This message has been edited by GamecockEE (edited 08-18-2004).]
Posted By: jdevlin Re: Gensets & Nat. Gas - 08/18/04 07:20 PM
"Has anyone here installed a NG/Diesel dual fuel unit yet?
Big bucks!!!"
There is such an animale????
$$$$$$ I imagine so........

My thinking on it is totally seperate deisel, or LP/NG dual fuel."

There is such a unit. It is called Bi-Fuel technology. It injects NG into the intake. If there is no NG the diesel just runs as normal on diesel.
My deisel mechanic has suggested this to us to extend a tank of deisel and reduce costs.
http://www.gti-aci.com/
Posted By: Roger Re: Gensets & Nat. Gas - 08/18/04 10:27 PM
e57,
Quote
There is such an animale????
$$$$$$ I imagine so........

My thinking on it is totally seperate deisel, or LP/NG dual fuel.

along with jdevlin's link you can also go Here for more info.

The one time we were asked to price this option for a medical facility it doubled the price of the gen set, this was about 5 years ago. They didn't take it.

Roger



[This message has been edited by Roger (edited 08-18-2004).]
Posted By: e57 Re: Gensets & Nat. Gas - 08/19/04 12:06 AM
While in the Military, my main job was generators..... And did not figure that a NG / Diesel were possible do to compression / ignition and cycle, Im going to take a look at the links you guys put up.... In my head, I say that there must be some sort of modification to allow this change over of fuel. What I have no idea...

Just for S&G, FYI type thing, all those guys in the green baggy pants.... All Miltary gear, sort of aircraft are multi-fuel in this way....(Generators, tanks, Humvee's, etc.) Diesel in any form, including kerosene, then JP-A,B, and JP-1 - 5. Seeing that all of the war stock-piles are JP grade 3-5, asking for fuel from them could be at your own risk...... You could end up with Jet fuel. (Which lacks some of the lubercating properties of most deisel grades, and much lower flash point)
Posted By: e57 Re: Gensets & Nat. Gas - 08/19/04 12:15 AM
Oh.....

It's not either or, you need both, in order to operate........ That doesn't sound cool! Well for this purpose, sounds way hip for other purposes... Like clean air and such.

"Uses deisel as a liquid spark plug"

"Bi-Fuel System operates by blending both diesel fuel and natural gas in the combustion chamber. This is achieved using a fumigated gas-charge design, whereby natural gas is pre-mixed with engine intake-air and delivered to the combustion chamber via the air-intake valve. The air-gas mixture is ignited when the diesel injector sprays a reduced quantity of diesel fuel into the chamber."
Posted By: iwire Re: Gensets & Nat. Gas - 08/19/04 12:19 AM
Well I did see a Cummings diesel converted to Nat Gas but it was not dual fuel.

It was a pretty slick conversion, injectors replaced with spark plugs each with their own coils.

I have no idea what they did about the high compression.
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