50 amp generator to a 30 amp transfer switch

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Old 07-15-14, 08:20 PM
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50 amp generator to a 30 amp transfer switch

I have a 17,500 portable generator and have installed a 50 amp transfer switch, which has a 30 amp inlet. The cord to connect the generator to the transfer switch has a 50 amp male on one end (generator end) and a 30 amp female on the other. Is this okay? My electrician says it is.

By the way, we plug it in and it melted the ground (green) wire in the transfer switch.
 
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Old 07-15-14, 10:21 PM
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What you have is NOT okay. You're now pushing 50A through a 30A rated fitting.
 
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Old 07-16-14, 05:14 PM
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What lights and appliances were turned on when the green wire of the transfer switch melted?

Most likely the melted wire was due to a loose connection (not necessarily the same wire) nearby.
 
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Old 07-16-14, 05:55 PM
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The green should not even be carrying current to have any heat to melt it. Are you sure everything is wired correctly?
 
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Old 07-19-14, 06:01 AM
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Update, we just tested the generator 50 amp outlet. From green to hot on one-side 125v, from green to hot on the other 240v. We think this is the problem. By the way, the same for the 30 amp outlet.
 
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Old 07-19-14, 07:19 AM
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From green to hot on one-side 125v, from green to hot on the other 240v. We think this is the problem.
Forget the green for now, what do you get when you measure from each hot leg to the white?
 
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Old 07-19-14, 08:08 PM
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The voltage between white and X or Y (hot) was 120v each
 

Last edited by ResLur; 07-19-14 at 08:34 PM.
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Old 07-20-14, 05:33 AM
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The voltage between white and X or Y (hot) was 120v each
Those are the three current carrying conductors, the green shouldn't be carrying any current at all except for a fault current just long enough to trip the breaker at the generator. If the circuit breaker at the generator is 50 amp, everything between the generator and the 50 amp transfer switch must also be 50 amp rated, including the cord, inlet and both cord caps.
 
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Old 07-26-14, 07:04 AM
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But the original issue remains. Why did the ground melt? If the generator was sending through 120v on x and 240v on y, how did the current find its way to ground and melt the wire?
 
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Old 07-26-14, 07:24 AM
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"Is this okay? My electrician says it is."


Its disgusting that someone that considers themselves an "electrician" would OK such a setup and is further perplexed when it fails.

Are you paying this clown in beer? Because I sure wouldn't give him a red cent.
 
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Old 07-26-14, 10:45 AM
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But the original issue remains. Why did the ground melt? If the generator was sending through 120v on x and 240v on y, how did the current find its way to ground and melt the wire?
If the neutral is bonded on the generator and neutral is open, or if something is miswired the ground could definitely melt.
 
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Old 07-26-14, 11:52 AM
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I do give the electrician credit for discovering the defect in the generator, which turned out to be the primary problem. The new setup is as follows:

1. #6 cord/wire from generator to transfer switch
2. 50 amp male plug on one end of #6 wire/cord
3. 50 amp female on the other end of #6 wire/cord
4. 50 amp male on the transfer switch (Reliance pb50 plug). Rated for 12,500 watts

Remember the primary goal - The 15.5 kw generator will serve as backup power during power outages in our area - which are often. I have a reliance transfer switch rated 12.5kw watts that will allow me to run various circuits within our home.

Once again, than you all for your comments. Thank guys are a great source of information.

Larry
 
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Old 07-26-14, 11:00 PM
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Much better, this is how it's supposed to be.
 
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Old 07-30-14, 04:11 AM
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One update, I have decided to go with a transfer switch that is rated for a 15kw generator.

The new generator should arrive 8/14/14 and the electrician will then make all the necessary connections and installations.

I will let you guys know how it turns out.

Have a great day everyone,
Larry
 
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Old 08-02-14, 05:52 AM
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The #6-4 cord that I ordered arrive today. I had no idea it would be this large and heavy. The 15kw transfer switch is on order and the new 15.5 kw generator should be delivered next week. I am very excited about this project.

Take care,
Larry
 
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Old 08-09-14, 01:40 PM
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Update: The 15,500 generator arrived today. I have my electrical permit and the electrician arrives Monday to connect all components. I have a very good feeling about this, why, because I have done my homework and I have a great electrician. (Mostly the research, including help from you guys.) The electrician came by Thursday for a planning meeting. I know what you are thinking, this is a small job - so why the pre-planning meeting? I am a firm believer that many conflicts with contractors could be avoid via pre-planning meetings. It gives you an opportunity to mentally walk through the process and to ensure that both are on the same page. My electrician was not very excited about this approach at first, but indicated afterward that it was time well spent. Based on our meeting, he prepared a materials list and both of us know what to expect. No surprises. (By the way, I fully expect to pay him for the preplanning meeting)

I will let you guys know how it turn out Tuesday.

Take care, and again, thank you all for your assistance, Lord knows I needed it.

Larry
 
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Old 08-11-14, 05:33 PM
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Today's installation went well. The electricians did an outstanding job of installing all the components. When the installation was complete, the electrician used a voltage meter to test the new 15,500 generator. From 1) hot to hot - approximately 240 volts; 2) from neutral to hot (both) approximately 120 volts each; 3) from ground to hot - approximately 101 volts; 4) from ground to hot - approximately 161 volts. What are the changes that two different generators from the same company could be defective. We did not plug the new generator into the transfer switch. The matter is under discussion with the manufacture. Of course, Lowes will take the generator back, but I am so frustrated and tired with the process.

Regarding the above question - yes this is backup power for our home. We loose power often.

I am so disappointed.

Larry
 
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Old 08-11-14, 06:46 PM
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For what you're spending on this project you could be well into a standby unit.
 
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Old 08-15-14, 06:41 PM
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Justin,

You may be correct. The project budget is $3300. We obtained two quotes for a standby system at approximately $9000 each. The standby system does not satisfy are needs and is costly when it comes to propane. When without power, most of the time we are at work,and I would not feel comfortable leaving the house with the standby running. I only want it to run when we are at home.

Take care,
Larry
 
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Old 08-16-14, 06:17 AM
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We obtained two quotes for a standby system at approximately $9000 each.

Where in VA are you?
I'm very rarely above $8,000 with a 20 KW generator and 200 amp service rated switch and short gas line.

Price would be a little less since you're going with propane.
There are so many options with stand by systems and it can be operated manually.
 

Last edited by ray2047; 08-16-14 at 08:41 AM. Reason: Remove referer from quote.
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Old 08-16-14, 12:07 PM
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the new 15,500 generator. From 1) hot to hot - approximately 240 volts; 2) from neutral to hot (both) approximately 120 volts each; 3) from ground to hot - approximately 101 volts; 4) from ground to hot - approximately 161 volts.
Just curious, who is the manufacturer of the generator? I think I'd be taking it back to Lowes for a full refund and start looking at standby units as has already been suggested. I would not feel a bit uncomfortable leaving my house with a properly installed standby system running.
 
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Old 08-18-14, 06:30 PM
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Generac. I know that this is most likely surprising to you guys, as this company as a good name in the industry, and has sold many units over the years. But look, bad parts can make there way into any production line, so it happens. I think there products are for the most part reliable. Lowes has been great, and did take both generators back. They even contacted Generac on my behalf. I will continue to do busy with Lowes, when I purchase the 12kw Powermate next week.

Take care,
Larry
 
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Old 08-29-14, 07:54 PM
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Well, the new Powermate 12,500 generator is scheduled for delivery tomorrow, and I am hopeful that this generator is not defective. I had a very, very difficult time tonight with the promised delivery, but got it worked out, or so I think. Upon arrive, I am going to have my electrician test the voltage produced by the generator at the 50kw outlet. If this generator is defective, well, I am not certain what I will do. Hopefully, no ones luck is that bad.

Take care,
Larry
 
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Old 08-29-14, 08:11 PM
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I am going to have my electrician test the voltage produced by the generator at the 50kw outlet.
You won't have a 50 KW receptacle on a 12.5 KW generator.
 
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Old 09-01-14, 04:24 PM
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Success - Finally - The 12,500 Powermate arrive Sunday morning. My Electrician tested the 50 amp outlet on the generator today (before plugging into the transfer switch), and it checked out okay. Connected the generator to the transfer switch and we turned on the breakers one at a time. I am able to run the following without placing a lot of stress on the generator (all at once):

Mini Split HVAC
Kitchen Lights
Bedroom Lights
Well Pump
Water Heater
Two TVs
Microwave
Frig.

As you may remember, this was a one month project that turned into 5 months because the 50amp outlets on the first two generators were defective. I am very, very relieved that it is over. And I extend a Thank You to each one of you for your ideas and thoughts. What a nice group of individuals.

By the way, I still have about $3,300 into the project.

Take care friends,
Larry
 
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Old 09-01-14, 04:32 PM
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I meant 50 amp. Maybe I should edit my work before posting???
 
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