RV to power home temp

Johnny Hurryup wrote:
I have a few times. I just made a power cord with two male ends. FIRST..extremely important... shut off your main incoming circuit breaker in your home's panel. Then plug your motorhome's cord into the closest outlet in your home. Now half of the homes outlets will be powered. If it isn't the outlets you need, try plugging it into a different outlet. You will be back-feeding electricity to one of the two buss bars in your panel. One other thing, flip off any 220 volt breakers that are in your panel.( water heater, elec stove , well pump, clothes dryer etc)

PLEASE do not do this! PLEASE, PLEASE, pretty PLEASE do not advocate others do it! This is the dangerous and illegal way of doing things.

It's dangerous because you have a cord that, should it come unplugged accidentally, has exposed live prongs. It's also dangerous because you're relying on a human remembering to properly flip the breakers to be safe for the linemen etc. and human memory is not reliable. On occasion, people doing things like this cause other people to be injured or killed.

It's illegal because the NEC requires some approved positive means of transfer switching between separate power sources--which means either a dedicated transfer switch of some sort, or an approved mechanical interlock device for the breakers (making them the transfer switch), etc.

If you cannot or will not install an approved transfer switching system, then the only safe way to use a portable generator in a permanent house (with a hardwired connection to the electric utility) is to skip the building electrical system entirely and use extension cables to power whatever needs power. For an RV or perhaps a mobile home you could also plug the unit into the generator, given the appropriate cables and connectors, in which case it's of course no longer connected to the electric utility.

I have a few times. I just made a power cord with two male ends. FIRST..extremely important... shut off your main incoming circuit breaker in your home's panel. Then plug your motorhome's cord into the closest outlet in your home. Now half of the homes outlets will be powered. If it isn't the outlets you need, try plugging it into a different outlet. You will be back-feeding electricity to one of the two buss bars in your panel. One other thing, flip off any 220 volt breakers that are in your panel.( water heater, elec stove , well pump, clothes dryer etc)

Hi,

I had a proper transfer switch (six circuits) installed on my home. They now have units that fit right under the power meter. They are not cheap--but they are legal and they do not back feed the power lines.

Do it once, and do it right. This is nothing to "play" with.

The other solution is to have plugs installed so that a furnace, for example may be run from the generator.

I was pleasantly suprized how much I could run without overloading my Kipor 2800 TI inverter generator. I had a natural gas stove.

Computer, lights in stair wells, main floor bathroom, master bed room, fridge, freezer, sump pump, sundry other lights, and garage door opener.

JaxDad wrote:

DrewE wrote:
Having the neutral connected with the hots disconnected does not pose any threat of backfeeding the grid. You can't have a circuit with a single wire, and without a circuit there's no power transfer. Indeed, since the neutral is bonded to earth ground, it can't even rise or fall in potential very much at all.

A generator is back-feeding a house with the mains switched off. Power is out because of a windstorm, the ground is dry and there's poor conductivity to ground from ground rod.

Miles down the road a linesman is working on supposedly 'dead' cables, the 120 volts from the generator is now stepped via the transformer to 12k - 17k volts.....

No potential you say?

People can die from as little as 9 volts.

People HAVE died from this very situation.

What voltage is being stepped up? Where is the 120VAC potential on the secondary of the utility transformer? Only one wire is connected to the transformer, the neutral lead, and the other two are floating.

No backup generator transfer switch for a sticks-and-bricks house, at least any one that I've happened upon, switches the neutral.

DrewE wrote:
Having the neutral connected with the hots disconnected does not pose any threat of backfeeding the grid. You can't have a circuit with a single wire, and without a circuit there's no power transfer. Indeed, since the neutral is bonded to earth ground, it can't even rise or fall in potential very much at all.

A generator is back-feeding a house with the mains switched off. Power is out because of a windstorm, the ground is dry and there's poor conductivity to ground from ground rod.

Miles down the road a linesman is working on supposedly 'dead' cables, the 120 volts from the generator is now stepped via the transformer to 12k - 17k volts.....

No potential you say?

People can die from as little as 9 volts.

People HAVE died from this very situation.

Yes! We don't have many power outages, but if we do it's awesome to have a backup.

JaxDad wrote:

crawford wrote:
it people could read and see the interlock system it is safe and legal and yes you can back feed by turning off main and locking it out you can legally do it. I been doing it for years and never a problem.

It is absolutely NOT legal.

The NEC requires you use a transfer kit or interlock to abolutely ensure you can't feed power back onto the grid (which would be amplified up to 17,000 volts or so by going backwards through your transformer, by the way).

Turning off your mains also doesn’t completely disconnect your house either, it only breaks the two hot legs, the neutral bond remains. This could create potential in lines that the people working on them think are dead and therefore safe.

There’s a reason the cords used to connect this way are called ‘suicide cords’ or ‘deadman cords’.

I assumed (lacking any other information) that the interlock being described was NEC approved for that purpose. There are approved interlock kits that physically prevent the main breaker and the generator feed breaker from being turned on at the same time. (Here are some available from Home Depot.) Such kits, of course, aren't used with a suicide cord and a branch circuit, but require a dedicated generator power inlet or hardwiring the generator.

Having the neutral connected with the hots disconnected does not pose any threat of backfeeding the grid. You can't have a circuit with a single wire, and without a circuit there's no power transfer. Indeed, since the neutral is bonded to earth ground, it can't even rise or fall in potential very much at all.

An RV transfer switch has to switch the neutral because it is switching the neutral/ground bond (bonded at the onboard RV generator, not bonded for shore power), biut that's not a concern for a sticks-and-bricks house where the bond is at the main panel in both cases.

crawford wrote:
it people could read and see the interlock system it is safe and legal and yes you can back feed by turning off main and locking it out you can legally do it. I been doing it for years and never a problem.

It is absolutely NOT legal.

The NEC requires you use a transfer kit or interlock to abolutely ensure you can't feed power back onto the grid (which would be amplified up to 17,000 volts or so by going backwards through your transformer, by the way).

Turning off your mains also doesn’t completely disconnect your house either, it only breaks the two hot legs, the neutral bond remains. This could create potential in lines that the people working on them think are dead and therefore safe.

There’s a reason the cords used to connect this way are called ‘suicide cords’ or ‘deadman cords’.

Is there an outlet on the newer genaets to plug into. I remember in my neighbors old 00 RV there was a 30A and 20A outlets. Is there the same on the newer ones?

Gundog wrote:

wvabeer wrote:
I was hoping to back feed my house thru the shore power cord by killing the main power flip a switch in the motor home (separate transfer switch) and run a few items till power is restored. Maybe ad a twist lock at two points within the transfer switch, one at incoming power and other main gen power connecting to the cord depending which mode I'll be in.

Please don't. Use a transfer switch designed for this application do not trust your main breaker as a disconnect to the utility. I am a retired journeyman lineman and this can kill utility workers. I can't tell you how many failed main breakers I have seen.

If you back feed into the utility the 120/240 volt service feeding your house comes from a transformer that converts primary high voltage at the transformer to the 120/240 volts for your house. If you back feed into the transformer you create primary high voltage through the transformer. The transformer is a simple device feed high voltage in the top it makes secondary voltage out the bottom feeding your house feed secondary voltage into the transformer and it makes high primary voltage out.

Not just utility workers are at risk lets say you have a wire down on your street or 2 streets over and you back feed through your service and the neighbor kid moves the wire so he can play and dies or is maimed guess who is at fault or maybe the downed line starts a house fire etc. I know of one lineman personally that got killed by an illegal hooked up generator in Mariposa, CA and their have been more many more.

It doe not matter if your home is fed underground or overhead the threat is the same.

Best case scenario is the utility worker grounds the primary line and smokes your generator. Do NOT TRUST YOUR MAIN BREAKER TO BE A DISCONNECT TO THE UTILITY. A proper transfer switch is a break before make device that gives a physical separation to the utility service.

And even with turning off the main, will
It not still back feed on the neutral side? I thought I read that somewhere!