That probably depends on the generator and what else is connected to it. This computer is running on electricity from a generator, or more likely, several generators, in nuke plants, coal fireds, etc. scattered about the country. :-)
I don't see how a properly sized generator that puts out a good sinusoidal voltage and has good regulation will harm electronics. I'm sure if I'm wrong, several will jump in and say so.
Nope, this is probably the least sensitive, since the first thing the power supply does is convert it to DC, pump it through a 20kz ocillator and turn it cack to DC. The range of voltage and frequency for a switcher power supply is very wide. The monitor is more sensitive but they still are designed to be 50-60 hz so they can be sold in Europe. I have pentium "desktop" machines running in all of my cars as MP3 players on the cheapest 135w inverters I could buy and the wave form out of them is scary.
3 years, 130f ambients from the Florida sun and being turned on and off with the key hasn't killed one yet.
"sinusoidal voltage"??????
In Re: Backfeeding with a portable generator - REAL safety concerns??? on Fri, 10 Sep 2004 23:09:36 GMT, by Friday, we read:
It depends on the type and quality of AC current from the genset. Usually, small generators (under 6K) deliver poor quality.
The solution is to use an Uninterruptiple Power Supply (UPS) between the genset or house current and the computer. The UPS takes in juice to charge a builtin battery. This battery then feeds the computer and ensures a clean, constant energy source and gives you a chance to power down normally when the electricity stops.
This is exactly what the little honda 1K and 2K generators do now. Generator feeding DC to an inverter. Quiet, light, and very clean power. Pricey but well worth it. I just wish that they made a larger size one.
--Dale
Honda builds a five and seven thousand watt inverter models for home emergency power. Both have electric start and can be started automatically.
-- Tom H
Honda EU3000is:
R, Tom Q.
Hmm.
I knew it needed a dedicated circuit. After I completed the install, I realized the generator side of the install is not to code since the other half of the 220v feed from the generator supplies power to other outlets.
However, it didn't occur to me that a single twist lock outlet on the grid circuit that the furnace could plug into was a code violation. I'm guessing it has to do with the possibility of accidently plugging the furnace cord into another twist lock outlet on a different circuit. I'm not too concerned with that in my house since the only twist lock outlets are specifically for the furnace.
As of a few months ago, my town will no longer do any inspections or issue permits for any plumbing or electrical work done by homeowners. I interpret that to mean I better not ask my town electrical inspector, because we are now in a "don't ask/don't tell" environment. Judging by the work some of the structural and electrical "improvements" the previous owners of my house did on their own, this seems like a great way to improve building safety. *sigh* I guess I'll be visiting the library to see if they have a copy of the NEC with a loophole.
At least in the mean time if I subtract the numerous (several hazardous and easily avoided) electrical code violations I've taken out of my wiring, from this one violation I'm still a net improvement in my code compliance since I've moved in.
It would also be mighty stupid. In my case the furnace is normally supplied by a 120v circuit.
While it wouldn't suprise me if wheels on a gas furnace on a slightly sloped concrete floor is an acceptable loophole to the NEC, I'd rather live with a "seemingly safe" electrical code violation than a "seemingly unsafe" natural gas problem.
Many UL listed transfer switches use off the shelf household circuit breakers as their isolation elements (they do add a mechanical interlock)
This would seem to negate the failed main breaker argument.
A lockout padlock on the main breaker would go a long way toward removing danger.
In almost every case a back feed situation would result in an immediate generator failure (engine stalling or circuit breaker opening) due to loads in neighbor's homes. The exceptions would be very large generators or a very small isolated line section (no neighbors).
This all leaves the mistakes happen even to careful people issue. And in this case a mistake could lead to manslaughter charges.
Bottom line: Use extension cords or intall an approved transfer switch of some sort. Remove SPAMX from email address
Well, "built in" microwave ovens usually plug into a 15 amp outlet. (It's supposed to be a single circuit and all that but ....)
Likewise, in some places, dishwashers are plugged in. In many places, garbage disposals are pluged in. Likewise, window Air Conditioners are plugged in.
And in all these cases, there ain't a "twist lock" in sight.
So maybe things are "achanging."
A breaker is a single throw device. It cannot transfer a circuit. It would be interesting to see the switches you have in mind to get an idea of how they accomplish a positive transfer. Do you have a particular make/model in mind?
Only if it is used. And also, only if it is used in the correct sequence.
I do. I just installed a Kubota 30KW diesel generator for a customer and it came with a 200amp Cutler-Hammer ATS that uses two 225amp MCBs with a stupid see-saw mechanism that is operated by a small shaded-pole motor with a crank and limit switches. I must say I was not impressed when one of my mechanics had to manually trip the see-saw (to gain access to the terminal insulator guard) and the pivot bolt broke off. I told the customer that he better hope that doesn't happen during automatic operation. See for yourself:
Square D part # QCGK3
A metal bracket on a pivot that only allows one of two breakers to be on.. turn off the main breaker, pivot the bracket and turn on the generator breaker. If either breaker fails in the ON position there's gonna be a problem; evidently Square D isn't concerned about that.
Regards,
Jim
I tried unsuccessfully to find the post of the individual who stated that a lineman was killed because he had an inadequate ground in a situation where there was a back feed from a home generator. I would be interested in reading any written report but the root cause was not the home generator but the inadequate personal ground.
I am writing this with a gas driven generator supplying my house in order to burn up some old gasoline. I have tried to keep the lineman fatalities to less than 10.
I never qualified as a journeyman lineman but I did spend a lot of time as a ground man and then managed transmission line crews after I received my EE degree. I did though join the "Bird On The Line" Club when I touched 345 kV from an insulated bucket. I also played a key role in the development of 765 kV hot stick tools and practices.
Regards,
John Phillips
Wow! That sure looks ugly. Thanks for the link!
Thanks! That looks good. I hope it is made better than the one Paul described where the pivot bolt broke.
Yeah.. it kinda defeats the purpose, doesn't it?
breaker failure concerns aside, I like doing a 'whole house' transfer because all circuits are powered, not just a few. This helps with switched lighting.. where you couldn't plug the lamp in with an extension cord.
Something else to consider is that some of the more 'enlightened' power companies have realized that transfer switches are expensive and homeowners aren't likely to spend more on the approved transfer switch than they did on the generator (at least not in one lump sum) and so have offered transfer switches through the power company.
Still expensive, but many power companies will break the payment down and roll it into the monthly bill, with no finance charges added. The common system the power companies seem to be using involves pulling the meter and adding a adapter between the meter base and the meter. This adapter will energize the entire house (up to the capability of the generator). Pretty elegant design.. I'm sure many people in power failure prone areas would be willing to go for this.
Regards,
Jim
Yeah.. it kinda defeats the purpose, doesn't it?
breaker failure concerns aside, I like doing a 'whole house' transfer because all circuits are powered, not just a few. This helps with switched lighting.. where you couldn't plug the lamp in with an extension cord.
Something else to consider is that some of the more 'enlightened' power companies have realized that transfer switches are expensive and homeowners aren't likely to spend more on the approved transfer switch than they did on the generator (at least not in one lump sum) and so have offered transfer switches through the power company.
Still expensive, but many power companies will break the payment down and roll it into the monthly bill, with no finance charges added. The common system the power companies seem to be using involves pulling the meter and adding a adapter between the meter base and the meter. This adapter will energize the entire house (up to the capability of the generator). Pretty elegant design.. I'm sure many people in power failure prone areas would be willing to go for this.
Regards,
Jim
I don't know if this is what you're referring to..
"A construction crew consisting of a supervisor, three class A linemen (including the victim), a first class lineman, a groundman, and two truck drivers were assigned the task of correcting a malfunction in a de-energized three-phase powerline. When the crew arrived at the worksite, they found that one of the three phases had broken and fallen to the ground. The supervisor instructed the victim to relocate the damaged phase on the crossarm of the pole to better balance the load on the crossarm. As the victim began to climb the pole he was assured by the supervisor that the powerlines had been de-energized. When he attempted to relocate the damaged line he contacted another phase, was shocked, and slumped backwards, prevented from falling by his safety belt. The powerlines at the worksite had been energized by backfeed electrical energy from a portable gas generator being used on the circuit."
Regards,
Jim
This a "transfer switch" the utility around here will install for you. It fits between the meter base and the meter. PEC in the DC area was the first to use them. Since it's on the meter the Utility has to install them.
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