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#216681 - 01/22/16 03:05 PM Designing for Power Outages
renosteinke Offline
Cat Servant
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Registered: 01/22/05
Posts: 5305
Loc: Blue Collar Country
As I was setting up my generator this morning, one thing became apparent: I had no easy way to power my alarm, cameras, phone, and computers, short of putting the entire house on the generator.

So, I wonder .... is it a good idea to have a separate circuit, hopping from room to room, providing power to receptacles dedicated to these uses? One could even make this a circuit separate from the usual house wiring, powered only when the generator is in use. Power failure? Just move the plugs.

I almost think I have seen this arrangement in medical facilities- an "emergency" receptacle right next to the 'ordinary' receptacle.

I rather like this arrangement, as it makes the generator network completely separate from the utility-powered network ... no need for transfer switches, no chance of backfeed issues. While the NEC seems to assume transfer switching, I don't think a parallel network is forbidden.

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#216682 - 01/22/16 04:48 PM Re: Designing for Power Outages [Re: renosteinke]
LarryC Offline
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Registered: 07/05/04
Posts: 776
Loc: Winchester, NH, US
For "down the road" applications, perhaps a dedicated small panel feeding all of the generator powered circuits could be installed. If you decide to install a transfer switch later, some of the wiring is already installed. You would just have to move other dedicated circuits later. It would allow you to run the 240 V output of the generator and give you more power available for the larger loads during an extended outage.

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#216685 - 01/22/16 06:45 PM Re: Designing for Power Outages [Re: renosteinke]
HotLine1 Offline

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Registered: 04/03/02
Posts: 6804
Loc: Brick, NJ USA
Reno:

An inlet, backfed cb, and an interlock kit gets the gen power into your panel. You have to select the branch cbs you want to power up, Works fine for me, and a lot of others, and it's legal.
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#216686 - 01/22/16 06:51 PM Re: Designing for Power Outages [Re: renosteinke]
HotLine1 Offline

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Registered: 04/03/02
Posts: 6804
Loc: Brick, NJ USA
Reno:

Yes, there are multiple sources in some medical facilities. The "emergency", red HG duplex, and matching plate are from the gen.
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#216691 - 01/22/16 11:42 PM Re: Designing for Power Outages [Re: renosteinke]
gfretwell Offline

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Registered: 07/20/04
Posts: 9045
Loc: Estero,Fl,usa
I have a back feed inlet and an interlock kit here. I am really not that prepared tho. I do have a good panel directory but I have not really gone through and mapped the breakers I would want to have on and the normal load on them. Best case would actually be a load rating on each "emergency" breaker and a list of which will work with the others.
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#216692 - 01/23/16 07:09 AM Re: Designing for Power Outages [Re: renosteinke]
renosteinke Offline
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Registered: 01/22/05
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Loc: Blue Collar Country
Does anyone see a need for surge suppression on generator-fed circuits? Just how reliable is their voltage regulation (especially as your load varies)?

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#216695 - 01/23/16 10:43 AM Re: Designing for Power Outages [Re: renosteinke]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9045
Loc: Estero,Fl,usa
I doubt surge protection would buy you much on a typical portable generator. Your biggest problem is usually sags.

If I ever do decide to test my setup and I think of it, I will hook up my Dranitz and see what I have.
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#216697 - 01/23/16 03:47 PM Re: Designing for Power Outages [Re: renosteinke]
Potseal Offline
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Registered: 02/23/13
Posts: 197
Loc: Saskatchewan
When the day comes to reno the basement I plan on installing a standby gen with an automatic transfer switch. How big of a standby gen I plan on using is the debate.


Reno, are you mostly concerned with surge suppression for ccts powering electronics? I think I would have a UPS ahead of the generator to deal with that concern.
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#216698 - 01/23/16 06:32 PM Re: Designing for Power Outages [Re: renosteinke]
renosteinke Offline
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Registered: 01/22/05
Posts: 5305
Loc: Blue Collar Country
Potseal, as I see it, the joker in the sizing decision is the starting current required for motors. When your overall load is as small as mine - or when, in my case, all I'm powering right now is one motor - that starting current matters.

Now, my generator, even when bought at a bargain price, cost me more than many similar capacity generators that I see in some retail outlets? Why pay more? Well, the biggest differences are in the noise made and the reliability of the voltage regulation.

There's my concern about voltage spikes: the voltage regulation of the generator as loads change. I would hate for a high-voltage spike when the furnace motor stops to cause harm to any electronics that might be on line.

Yes, a UPS would help; I had forgotten about that. That might be a solution.

Greg, I'd love to see what actual measurements show.

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#216700 - 01/23/16 11:10 PM Re: Designing for Power Outages [Re: renosteinke]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9045
Loc: Estero,Fl,usa
These days electronics are really not what I worry about. They usually have switch mode power supplies that tolerate anything from 100v to 250 or so. It makes them easier to sell around the planet.
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