eu2000i through southeast tornados

[engineerscott]

On the Power Transfer Switch - maybe you guys can help me find what I'm looking for.

What I want is very simple. Currently just past the utility's meter (on my side of the demarcation) there is a service disconnect, as is required by most electrical codes. The service disconnect is nothing but a SPDT 200A switch. What I want is a Power Transfer Switch to replace the service disconnect that is a DPDT switch, and on the new pole I'd simply add an appropriate plug for the generator. It would still serve as a disconnect, but when in the position to disconnect power from the utility it would connect to the generator receptacle.

This is the simplest setup I can imagine. It would place the burden on me to open all the breakers in my service panel for loads that I do not want or can not power, but to me the simplicity far outweighs that chore. It also means that I don't have to modify anything in the service panel.

Has anyone seen a PTS that works like this?

 

[eljefino]

You probably have to call the electric utility to have them pull the meter to work at this switch. This might be free or might be expensive.

But if you kill this switch, the dead side is open season, and you can splice into the wire somewhere between it and your breaker panel for your transfer switch.

 

[engineerscott]

Yeah, I'd certainly have to call the utility company to remove the meter. I don't think they charge for this in my area.

Yes, in theory I could install a plug on the house side of the service disconnect, but this would not meet code as I could connect the generator to the house wiring without disconnecting from the utility (potentially exposing a lineman to hazardous voltage on the high side of the stepdown transformer) or almost as bad, have a generator supplying asynchronous voltage to the live grid. I'd really like to do it code compliant.

What I really need is a 200A DPDT switch in place of my service disconnect (or alternatively after the disconnect). This way it is physically impossible for the generator to backfeed the grid or to drive against the live grid. Surely someone makes this.

 

[engineerscott]

Wow, been pricing 200A DPDT PTSs on the internet. These things cost more than the generator I'm using.

 

[meep]

That's a whole-house xfer switch-- they are certainly out there- I've seen them while researching all this recently. may be easier to just work inside the panel?

M

 

[eljefino]

I was not clear, but you can put that DPDT switch in the wire after the on off switch. I assume they have meters or pilot lights to show you when shore power is back on.

 

[irq3]

What Brand of panel are you using? If you have space, you can install a generator interlock. It uses two breaker spaces at the top of the panel. Square-D sell their own or look at Generator Interlock Kits. No meter pull or transfer switch is necessary.

 

[engineerscott]

Originally Posted By: meep
That's a whole-house xfer switch-- they are certainly out there- I've seen them while researching all this recently. may be easier to just work inside the panel?

M


From my way of thinking the whole house PTS is the way to go, at least if I can find one that least costs a little less than the generator.

With the whole house switch I can throw open all the breakers in my service panel and then add and remove loads as I see fit. With these "sub panel" transfer switches I have to pick which circuits I want to run in an outage and then hairpin those circuits through the sub panel, which of course means I can't connect any circuit that I didn't pick ahead of time. I'd rather have the option of running any combination of circuits my generator will handle.

Plus, all of the sub panel transfer switches I've see are surface mount. The service panel I'd be attaching to in my garage is flush mounted into the drywall, so I'd have this panel sticking out.

 

[engineerscott]

Originally Posted By: irq3
What Brand of panel are you using? If you have space, you can install a generator interlock. It uses two breaker spaces at the top of the panel. Square-D sell their own or look at Generator Interlock Kits. No meter pull or transfer switch is necessary.


Yeah, the interlock breakers are acceptable to me, but I haven't seen one that will support a 200A service, most I see are 60A. Maybe that link you gave me will show that they do make one that big, if so that's probably what I'll do.

 

[engineerscott]

Originally Posted By: eljefino
I was not clear, but you can put that DPDT switch in the wire after the on off switch. I assume they have meters or pilot lights to show you when shore power is back on.


Right, I accept that I don't actually have to replace that the service disconnect but can instead put that DPDT switch in series just after it. In some ways that is advantageous since I could just open the service disconnect to install it - I wouldn't have to get the utility company to come out and remove the meter.

 

[Craig in Canada]

Originally Posted By: engineerscott
Originally Posted By: irq3
What Brand of panel are you using? If you have space, you can install a generator interlock. It uses two breaker spaces at the top of the panel. Square-D sell their own or look at Generator Interlock Kits. No meter pull or transfer switch is necessary.


Yeah, the interlock breakers are acceptable to me, but I haven't seen one that will support a 200A service, most I see are 60A. Maybe that link you gave me will show that they do make one that big, if so that's probably what I'll do.



This is the kind of approach I intend to take, along with a 30/50A twistlock suicide plug to bring the power to the panel from outside.

I really don't need a generator, but I want one. I think the last time the power was out was the big 2003 blackout and even then we were back on by 10pm the first night I think. I'm probably forgetting some very short outages, but...

What I'd like to do is find a nice 3k-5k generator on the side of the road that needs a little small engine TLC, then convert the carb to natural gas and find a spot to locate the unit on my deck. I might build a decorative "bench style" cover to hide it during the 99.9999% of the time it isn't in use. I could bring a 50A twistlock receptacle out to the deck along the same route I brought the gas line and do the suicide plug thing to backfeed the panel. Add an interlock et voila.

Of course I haven't been successful at the "find a nice generator on the side of the road" part of the plan since inception in 2003

 

[meep]

"find a nice generator on the side of the road"

I always dreamt of that.

I ended up "finding" one with a little help from my wallet...

 

[dakota99]

If you want to install a double pole breaker with an interlock kit, you might want to consider one of these to mount outside your house.

http://www.reliancecontrols.com/ProductDetail.aspx?PB30

It's basically an inlet receptacle designed to be used with a transfer switch but all you have to do is run your 10/3 (for a 30 amp service) from this inlet to the double pole breaker. This is what i did and it works fine. Much cheaper than the whole transfer switch setup. I also find it to be more "clean" than a suicide plug setup but essentially its the same.

 

[raffy]

I also used a Honda EU2000i generator after the tornado outbreak of April 27. I was a little low on gas so I only used it to keep the refrigerator cold and to run the desktop computer, along with charging cell phones, iPhone, iPod, etc. I would typically run the refrigerator 3 times a day (in the morning, afternoon and evening) and then leave it off for the whole night till the next morning. This saved our frozen and refrigerated food and also saved a lot of fuel and reduced the run time on the generator. I used less than a gallon of gas per day this way and that really helped for the 4+ days that we were without power. I figure I put about 30 hours or so on the generator during that time.

It had a fresh oil change in it but I went ahead and changed the oil afterward anyway. I use Amsoil 5W-30 synthetic in it and all our other small engines.

I purchased a Honda EU1000i genset after this disaster just to have another genny around. The other day I tried it with our refrigerator and it will also run it. The overload light does come on for a second or so as the fridge motor starts, but once the fridge is running, the EU1000i is fine and loafs along in eco mode. No problem at all. Our fridge is a recent (purchased in 2007 I think) model Kenmore made by Electrolux and is approximately 21 cu ft. So the EU1000i might be a good option if you're just looking for a generator to power your fridge and maybe a laptop during a power outage. It's almost 20 lb lighter than the EU2000i, and that makes for easier carrying!

 

[tig1]

Originally Posted By: eljefino
Originally Posted By: meep
I did not like the arrangement of cords everywhere, and would like a better solution. would LOVE to install a transfer switch at the breaker panel. THATs the way to do it. Never really gave it much thought before, but now I think I may look into it.

M


That is the way to do it, but I know someone who gets by with a suicide plug (male on both ends) and the main breaker off. The name of the device says it all.


I run my generator that way.(back feed) I plug my cable into the welder outlet. With the main off I power the whole house, but have to be selective with the power management. Works very well.

 

[MI_Roger]

Originally Posted By: Gene K
We have been going through 20,000 dollars a day worth of Diesel Fuel at work to run the Generators.


I am amazed by those crazy IT folks who insist the back-up generators for their data centers use diesel oil rather than natural gas! Do they really think fuel delivery via tanker truck is more secure and reliable than a pressurized natural gas main?

Sure the mains can rupture in the most severe disasters. But will the roads still exist and be open for traffic following the same event?

 

[wolfc70]

Originally Posted By: MI_Roger
Originally Posted By: Gene K
We have been going through 20,000 dollars a day worth of Diesel Fuel at work to run the Generators.


I am amazed by those crazy IT folks who insist the back-up generators for their data centers use diesel oil rather than natural gas! Do they really think fuel delivery via tanker truck is more secure and reliable than a pressurized natural gas main?

Sure the mains can rupture in the most severe disasters. But will the roads still exist and be open for traffic following the same event?


Natural Gas works fine for up to about 80-100KW units. After that it takes a lot of gas to handle the load, and this usually means upgrading the gas service from the street. Very expensive to do. Also natural gas units are very expensive if you need Tier III emission requirements. I just had a Cummins 200KW gen set installed where I work. The new common rail diesels are great. Very little diesel clatter, no smoke and very easy starting in cold weather. A comparable natural gas unit (Tier III compliant) was about $15K more that the diesel, and that included the 350 gallon tank.

IMHO, for larger gen sets, diesel is the only way to go.

 

[engineerscott]

Natural Gas is great if your gas service is large enough for the number of kWs you need to generate. Not a problem for the average residential or even most commercial businesses, but I can see where a large server farm might need more power than a default gas service could provide.

The great thing about natural gas is that it is so clean burning that your engine maintenance is greatly reduced, and as you point out, no delivery trunks to get the fuel to you. I've been through some major long term power disruptions (tornadoes and ice storms) and in none of them has the natural gas service been interrupted. The only natural disaster that I would think would have a major likelihood of disrupting the natural gas infrastructure would be earthquake, and that risk would be very dependent on geography. Even then, delivery of diesel by truck via surface roads might well be down as well in such an event.

 

[irq3]

Doesn't natural gas rely on electric pumps throughout the system? If there is a major utility outage, there may be a partial or complete loss of gas pressure. This makes it unreliable and that is why most data centers use diesel. You could always use propane stored on site.

 

[meep]

Originally Posted By: irq3
Doesn't natural gas rely on electric pumps throughout the system? If there is a major utility outage, there may be a partial or complete loss of gas pressure. This makes it unreliable and that is why most data centers use diesel. You could always use propane stored on site.


oh no, I know this is bad.... but I can't resist... maybe the electric natural gas pumps would rely on natural gas for backup power....



Server Farm- also consider that the heat density of today's servers can be quite high--- so every KW of power consumed = a KW of heat--- so the chillers have to run as well. The conversion --- i don't recall off-hand, but isn't it like a factor of .4kw of power needed to cool every kw of heat to be removed.... so a 10kw server farm (pretty small) would have an estimated 4kw power used to run chillers....

the local hospital runs 20x7kw mainframes, with additional on standby. thats 140kw of juice, not including standby systems, plus 56kw of chiller load.... 200kw... just for a hospital data center.

M