Generator Hassles
in [Design]
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From: Sylvia Else on 12 Aug 2010 05:38 On 9/08/2010 12:50 AM, Jon wrote: > The electrical service goes to the house. There are 3 underground 000 > cables that go to the barn from the house. The barn has a 60 amp breaker > in the breaker box at the house. The 12,000 watt generator is in the > barn. It has a 50 amp 240vac outlet, a 30 amp 240vac outlet and several > others. I am hooking the 50 amp outlet to the house. I am using the same > 3 underground 000 cables to send generator power to the house during a > power outage. > > A 90 amp contactor in the barn won't connect the generator to the house > unless: > 1. The electrical service to the house is off, and > 2. The service disconnect switch at the house is off. > > When the generator is turned on, it tests the service disconnect at the > house to assure the above two conditions are met. This is done by > sending a 1 second electrical pulse to the house to see if it will > actuate a coil. If the coil actuates, the 90 amp contactor latches open > and prevents backfeed into the grid. If the service power turns on > during that 1 second, the generator power and service power will clash > and throw a 50 amp breaker to the generator. > > http://jons-math.bravehost.com/transfer.html > > > I'd have thought the grid operator would want a cast-iron guarantee that you won't backfeed the grid, lest you enliven wires that linesmen think are dead. What's wrong with a DPDT relay? Sylvia.
From: Jasen Betts on 12 Aug 2010 06:28 On 2010-08-09, PeterD <peter2(a)hipson.net> wrote: > On 9 Aug 2010 11:02:02 GMT, Jasen Betts <jasen(a)xnet.co.nz> wrote: > >>On 2010-08-08, Jon <jon8338(a)peoplepc.com> wrote: > >>> If the service power turns on during that 1 second, the >>> generator power and service power will clash and throw a 50 amp breaker to >>> the generator. >> >>if you're lucky. >> > > Actually it'll probably blow his generator, and resolve the problem > almost immediately... With luck, Jon will be fondleing it at the time. that's now way it could go, another is the gernerator could phase-lock with the mains. and continue to run. --- news://freenews.netfront.net/ - complaints: news(a)netfront.net ---
From: PeterD on 12 Aug 2010 07:40 On Thu, 12 Aug 2010 03:01:28 -0700, "Very Sick Edmond Wollmann" <arcturianone(a)earthlink.net> wrote: > >True, but he tried not to do that, that's why he struggled with his transfer >circuit. > Again this makes too many hazardous assumptions about conditions and Jon's ability to do things. Since he's proven he can not design a simple transfer switch, there is little hope that he will have ideal conditions for his system to work. One problem is that Jon engineers for best/ideal conditions, and not worst case conditions. That is what seperates a real engineer from a wanna-be like Jon.
From: Michael A. Terrell on 12 Aug 2010 12:36 Sylvia Else wrote: > > On 9/08/2010 12:50 AM, Jon wrote: > > The electrical service goes to the house. There are 3 underground 000 > > cables that go to the barn from the house. The barn has a 60 amp breaker > > in the breaker box at the house. The 12,000 watt generator is in the > > barn. It has a 50 amp 240vac outlet, a 30 amp 240vac outlet and several > > others. I am hooking the 50 amp outlet to the house. I am using the same > > 3 underground 000 cables to send generator power to the house during a > > power outage. > > > > A 90 amp contactor in the barn won't connect the generator to the house > > unless: > > 1. The electrical service to the house is off, and > > 2. The service disconnect switch at the house is off. > > > > When the generator is turned on, it tests the service disconnect at the > > house to assure the above two conditions are met. This is done by > > sending a 1 second electrical pulse to the house to see if it will > > actuate a coil. If the coil actuates, the 90 amp contactor latches open > > and prevents backfeed into the grid. If the service power turns on > > during that 1 second, the generator power and service power will clash > > and throw a 50 amp breaker to the generator. > > > > http://jons-math.bravehost.com/transfer.html > > > > > > > > I'd have thought the grid operator would want a cast-iron guarantee that > you won't backfeed the grid, lest you enliven wires that linesmen think > are dead. > > What's wrong with a DPDT relay? Jon is a troll.
From: Josepi on 12 Aug 2010 23:09
We don't care about your communication failures. "Michael A. Terrell" <mike.terrell(a)earthlink.net> wrote in message news:YuSdnQXFp-ixvvnRnZ2dnUVZ_rCdnZ2d(a)earthlink.com... Jon is a troll. |