Connecting Onan 5500 to Home Transfer Switch

[MLP]

I am surprised that for less than 5.8k you can have a back up generator that will keep your home and pool good to go. It is automatic and reliable. Why fool around. We are on a power grid that connects with a school. When we had a little earthquake, Loma Preda, we lost power until 4 AM in the morning. Yes I road it out in my hallway! Watched the Candle Stick Park come on the TV and then the power went out , big, did I say BIG low frequency wave, and BAM! So why did it take it till 4 AM in the morning? Well the school had to be inspected until the power would be restored. All streets including across the street had power restored within 90 minuets. Running a propane or natural gas line will add cost, but once done, it is forever fixed. A sub panel can be installed to handle all circuits to be powered by the generator with a transfer switch and it will be auto started. TV, lights, refrigerator, pool, etc.. So save and do it correctly and do not worry about it. It does add value to your property as well. I lost power do to fires for ten hours several years ago. I purchased a portable gen that runs on propane or gas. TV, refrigerator and the freezer, along with two lights are powered. I can also, if needed, power the furnace. Some in the area lost power for twelve days. In the future, I will install a permanent generator setup. I will replace the current breaker box, add a secondary breaker box, along with the natural gas line. It is on the things to be done list. --- Now you may ask why 12 days? The power companies do not have spare transformers any more. Pressured to reduce cost by the public utility commission, they saved money by not having spare parts around.

[dkoldman]

Originally Posted by 16ACE27

Think about it: do you think the RV repair shop has a certified electrician in the shop? Or is the same guy that swaps out batteries the guy that will do your receptacle installation and may have less of a handle on 120/240 VAC wiring than you do.

If it warms up between now and then, I will consider.

I guess I am being kind of lazy, I will pay $150 to avoid the hassle, but if they want $300 - $400 I will figure it out.

My doubts are...
1. Disconnecting the genny wiring for ATS switch
2. Mounting a receptacle box on the back wall
3. Having to double up the X, Y, W & G wires to the back of receptacle so power can flow through receptacle and still go to ATS.

[16ACE27]

Originally Posted by dkoldman

If it warms up between now and then, I will consider.

I guess I am being kind of lazy, I will pay $150 to avoid the hassle, but if they want $300 - $400 I will figure it out.

My doubts are...
1. Disconnecting the genny wiring for ATS switch
2. Mounting a receptacle box on the back wall
3. Having to double up the X, Y, W & G wires to the back of receptacle so power can flow through receptacle and still go to ATS.

Not the way to do it. Get a junction box, find the feed cable from the generator to the ATS, determine where is the best location to install the junction box so you can cut the wires in the cable and splice them back together along with the wires for the cable going to the receptacle location. Use heavy duty connecters for these 3-way but splices.

An alternative would be to put the junction box right before where the generator cable enters the ATS and run the receptacle cable back out to the preferred receptacle location.

[dkoldman]

Originally Posted by MLP

I am surprised that for less than 5.8k you can have a back up generator that will keep your home and pool good to go. It is automatic and reliable. Why fool around. We are on a power grid that connects with a school. When we had a little earthquake, Loma Preda, we lost power until 4 AM in the morning. Yes I road it out in my hallway! Watched the Candle Stick Park come on the TV and then the power went out , big, did I say BIG low frequency wave, and BAM! So why did it take it till 4 AM in the morning? Well the school had to be inspected until the power would be restored. All streets including across the street had power restored within 90 minuets. Running a propane or natural gas line will add cost, but once done, it is forever fixed. A sub panel can be installed to handle all circuits to be powered by the generator with a transfer switch and it will be auto started. TV, lights, refrigerator, pool, etc.. So save and do it correctly and do not worry about it. It does add value to your property as well. I lost power do to fires for ten hours several years ago. I purchased a portable gen that runs on propane or gas. TV, refrigerator and the freezer, along with two lights are powered. I can also, if needed, power the furnace. Some in the area lost power for twelve days. In the future, I will install a permanent generator setup. I will replace the current breaker box, add a secondary breaker box, along with the natural gas line. It is on the things to be done list. --- Now you may ask why 12 days? The power companies do not have spare transformers any more. Pressured to reduce cost by the public utility commission, they saved money by not having spare parts around.

Are you familiar with the term "Scope Creep"

You would need to know my journey to understand....

My wife and I are (were) big time campers on lakes with our boat. About 13 years ago we bought a 3500 watt generator off ebay that was Chinese made that everyone said would not last 1 year and I would never find parts. It almost twice the output of the Honda 2000 and $.25 on the dollar. It was cheap, I bought it as a toy so we could camp anywhere. It worked great. The Macho in me wanted to use it more after year or two, it had a 3 year warranty. So I bought and wired myself the Connecticut Electric Transfer Switch so I could use my generator as a backup. I wired up 10 circuits and it has worked perfectly for about 12 years now. Both fridges stay power and we have power in all rooms of the house, we can even use the microwaves & can run heat and all ceiling fans. So 2 1/4 years ago we buy an RV Onan 5500. I then learned and start to question why can't I use my already owned 5500 to my already owned 7500 transfer switch? So I have spent about $40 and just haver to install it.

Yes it would be nice to have pool wired in, but I am not gonna make that kind of investment me to do. I could have should have winterized my pool equipment but we have never had too until last February In future if we think power is going to be out days I will drain the pool heater and pumps. Unfortunately last year, the pool had frozen before we knew what was going on and that the state of Texas could not get more power.

We also have the option of staying in the RV as backup.

And now for my real reason. If the new Ford 150 Electric trucks can supply power to my home transfer switch, why can't my RV? You might say I am on a mission to make my RV more valuable to us. So far we just loving it ...

[dkoldman]

Originally Posted by 16ACE27

Not the way to do it. Get a junction box, find the feed cable from the generator to the ATS, determine where is the best location to install the junction box so you can cut the wires in the cable and splice them back together along with the wires for the cable going to the receptacle location. Use heavy duty connecters for these 3-way but splices.

An alternative would be to put the junction box right before where the generator cable enters the ATS and run the receptacle cable back out to the preferred receptacle location.

That sounds easier and I just might be able to do it now

When I last looked; there was about 6 inches excess of wire / conduit going into ATS. I didn't think or know to get a junction box: rolleyes: I have plenty of wing twist wire connectors (#12). Let me get back to Lowes this weekend and find a nice junction box that will take my existing conduit size. I am sure I have some conduit left over from when I wired my RV Pedestal.

This method not only keeps me out of my Southwire ATS box, but it is the right way which coincidentally makes the wiring easier.

[Chateau_Nomad]

Due to a Derecho in 2008 and again in 2012, we were without power for almost a week... both times... in summer.

Fortunately in 2006 I had bought a 6500 construction genny and had a manual transfer switch installed. It ran everything but the A/C. I even ran extension cords to two neighbors for lights and fridge. I still have that genny - like new still - sitting here in the garage, always ready to go.

My brother who's 150 miles away got hit by the same storms. He went full tilt... 14k whole house Generac after the fact. He said NEVER AGAIN.

So... in over 13 years, the power hasn't been off at our house for over 30 minutes but maybe 3 times... and two of those were planned outages. I came VERY close to "upgrading" to a whole house Generac or similar, but I'm glad I didn't. That's 10k I can spend on RV life, ceramic sprays and I might even splurge on a Makita air compressor! . Just thinking how much I'll save not buying pink RV antifreeze makes me giddy!!

Besides, it's a balmy 4° here in Ohio... who needs stinking antifreeze??

[dkoldman]

Originally Posted by Chateau_Nomad

Due to a Derecho in 2008 and again in 2012, we were without power for almost a week... both times... in summer.

Fortunately in 2006 I had bought a 6500 construction genny and had a manual transfer switch installed. It ran everything but the A/C. I even ran extension cords to two neighbors for lights and fridge. I still have that genny - like new still - sitting here in the garage, always ready to go.

My brother who's 150 miles away got hit by the same storms. He went full tilt... 14k whole house Generac after the fact. He said NEVER AGAIN.

So... in over 13 years, the power hasn't been off at our house for over 30 minutes but maybe 3 times... and two of those were planned outages. I came VERY close to "upgrading" to a whole house Generac or similar, but I'm glad I didn't. That's 10k I can spend on RV life, ceramic sprays and I might even splurge on a Makita air compressor! . Just thinking how much I'll save not buying pink RV antifreeze makes me giddy!!

Besides, it's a balmy 4° here in Ohio... who needs stinking antifreeze??

I just can't follow why anyone would want to buy a whole house Generator? I mean what is the point To miss out on the thrill of hooking up a portable generator and being forced to rough it on the inside of your warm home with all your lights with TV going next to fireplace? A frozen pool gives your back yard ambiance, it is a natural outdoor man made ice skating rink.

We had this Sinemate 3500 run for about 5 days "continuously" (word of the day)

We use the generator about 4 times per year for power outages, but most are 3 hours or less. The previous long was a 1 full day when a transformer blew. It happened during the day, but by the night, the entire block was pitch dark; but our house was lit up like a Christmas tree.

It will be Kool when I can feed the house 5500 watts power from the RV for the following reasons.

1. My 5500 is quieter than Portable 3500 although the Sinemate is not that loud.
2. More power, I don't think I will ever trip a breaker on 5500. Today is both refrigerators compressors kick on at about the same time, my 3500 will trip a breaker.
3. Easy to put a full load on Onan 5500 when ever I want
4. I don't have to worry about trying to lock the Onan 5500 up fearing it could be stolen like the portable
5. It was a real PITA to keep the portable filled with gas. I was getting about 7 hrs and had to get up in the middle of the night to refill with gas to keep it from shutting off.
6. My wife can easily setup and run the RV Generator, versus having to move and setup the portable.

[Chance]

Why did you select L14-30R? Doesn’t that limit generator power output to 30 Amps? Reading thread I didn’t see how you get full generator power through that receptacle. What am I missing?

I’m not sure of details of what you have at house end, but I would probably take different approach at motorhome.

[16ACE27]

Originally Posted by Chance

Why did you select L14-30R? Doesn’t that limit generator power output to 30 Amps? Reading thread I didn’t see how you get full generator power through that receptacle. What am I missing?

I’m not sure of details of what you have at house end, but I would probably take different approach at motorhome.

That's 30 amps at 240 VAC or in the RV world, two legs of 120 VAC/30 amps.

But that does bring up a good point: Since the Onan does provide those 2 legs in phase, a common neutral will have to be able to handle 60 amps. That is at the plugs and through the cable. That IS the weak spot in this plan.

[Chance]

Originally Posted by 16ACE27

That's 30 amps at 240 VAC or in the RV world, two legs of 120 VAC/30 amps.

But that does bring up a good point: Since the Onan does provide those 2 legs in phase, a common neutral will have to be able to handle 60 amps. That is at the plugs and through the cable. That IS the weak spot in this plan.

Exactly, it’s the wrong receptacle.

Why not just add a 50-Amp breaker at motorhome panel and power a standard 50A receptacle? That way both legs, ATS, etc. is taken care of and minimizes his chance of screwing up generator and or transfer switch wiring.

Plus he already has long 50A extension cord.

Also, I would want rest of motorhome left powered from generator at same time so battery charger could be left on during long power outages.

I’d just add a 50A receptacle somewhere in motorhome. Since it’s only for emergencies at home, it could be in an outside compartment, or even inside though not my first choice.

[16ACE27]

Originally Posted by Chance

Exactly, it’s the wrong receptacle.

Why not just add a 50-Amp breaker at motorhome panel and power a standard 50A receptacle? That way both legs, ATS, etc. is taken care of and minimizes his chance of screwing up generator and or transfer switch wiring.

Plus he already has long 50A extension cord.

Also, I would want rest of motorhome left powered from generator at same time so battery charger could be left on during long power outages.

I’d just add a 50A receptacle somewhere in motorhome. Since it’s only for emergencies at home, it could be in an outside compartment, or even inside though not my first choice.

That's what he's doing.

[Chance]

Sorry, thought he was trying to add another transfer switch in series to power house. Either way, since generator is rated at 46 Amps (more or less), assuming he has an open slot in panel, it seems easier to me to tie in there with a breaker.

[Bill Johnson]

Originally Posted by 16ACE27

You will need the output from BOTH breakers to connect to you receptacle and get the full 5500 watts available. If your pool pump/heater run on 240 volts this will not work as the 5500 does not provide 240 VAC out, just two lines of 120 VAC, in phase.

I was just reading a post from 2019 about the generator and Onan told this person that it can do 240 volt. Each leg must be a different phase. Many RV's have clothes dryers that are 240 so it just makes sense that he has it and can run almost anything

[dkoldman]

Below is a picture of my parts. I wound up by a Cantex for junction box with 3/4" hole and one adapter to convert into 1/2"

When / if I get bold enough I will cut the feed going into existing ATS.

Generator power will come in at the top and feed out of the bottom to the ATS. A third line 1/2" will come out of the top to the L14 - 30R

[dkoldman]

Originally Posted by Chance

Why did you select L14-30R? Doesn’t that limit generator power output to 30 Amps? Reading thread I didn’t see how you get full generator power through that receptacle. What am I missing?

I’m not sure of details of what you have at house end, but I would probably take different approach at motorhome.

Is there any Chance that if I said "By Chance"; you would except that or simply say No Chance

L14 -30R is what my existing 40' cord and Connecticut Electric Transfer Switch accepts.

When I connect the past 10 years or so with my portable generator; I only had 1 leg of 120 vac coming from generator and with adapter the 30 amps was split across both legs so more or less I really had about 15 amps on both banks of my Transfer Switch. It worked well.

But now, if I complete this, I should have 30 amps for real on both legs ( so that is 60 amps total. My transfer Switch can handle 7500 watts and I will not get close that topping out at 5000 - 5500 or so.

If I exceed 30 amps on any leg, I would expect my one of generator breakers to trip.

[dkoldman]

Originally Posted by Chance

Exactly, it’s the wrong receptacle.

Why not just add a 50-Amp breaker at motorhome panel and power a standard 50A receptacle? That way both legs, ATS, etc. is taken care of and minimizes his chance of screwing up generator and or transfer switch wiring.

Plus he already has long 50A extension cord.

Also, I would want rest of motorhome left powered from generator at same time so battery charger could be left on during long power outages.

I’d just add a 50A receptacle somewhere in motorhome. Since it’s only for emergencies at home, it could be in an outside compartment, or even inside though not my first choice.

Houston, I may have a problem? My existing cord is 30A. It is NOT a RV cord of any type. My portable generator is only capable of 30 amps and my transfer switch also accepts 30amp.

So does this mean, I should only wire up one leg to the L14 - 30R ?

If so; I then would need to know which 30 amp breaker on the 5500 to use?

[dkoldman]

Originally Posted by Chance

Sorry, thought he was trying to add another transfer switch in series to power house. Either way, since generator is rated at 46 Amps (more or less), assuming he has an open slot in panel, it seems easier to me to tie in there with a breaker.

I think I am getting where you going. I have not looked at electrical panel inside of the RV. I think if I did this, I would need a 30 amp breaker to work with my existing transfer switch. But this would be a very costly option to run the 30 amp wiring from inside of RV to electrical compartment.

What I don't understand is how can I have a 7500 watt Transfer switch if it can only accept 30 amps? I was think 30 amps for each leg and with two legs it is total of 60 amps but max of 30 amps on each line?

If so; I think my plan was sound? But I am listening

Here is my transfer switch
https://www.amazon.com/EGS107501G2KI...99583010&psc=1

[16ACE27]

Originally Posted by Bill Johnson

I was just reading a post from 2019 about the generator and Onan told this person that it can do 240 volt. Each leg must be a different phase. Many RV's have clothes dryers that are 240 so it just makes sense that he has it and can run almost anything

Just because "Many RV's have clothes dryers that are 240" doesn't mean he does, And Onan does make generators that produce 240 VAC, but the 5500 does NOT produce split-phase 240 VAC voltage.

[16ACE27]

Originally Posted by dkoldman

I think I am getting where you going. I have not looked at electrical panel inside of the RV. I think if I did this, I would need a 30 amp breaker to work with my existing transfer switch. But this would be a very costly option to run the 30 amp wiring from inside of RV to electrical compartment.

What I don't understand is how can I have a 7500 watt Transfer switch if it can only accept 30 amps? I was think 30 amps for each leg and with two legs it is total of 60 amps but max of 30 amps on each line?

If so; I think my plan was sound? But I am listening

Here is my transfer switch
https://www.amazon.com/EGS107501G2KI...99583010&psc=1

L14-30 can handle up to 7500 watts at 240 VAC but only half that at 120 VAC even if you do have two hot because you only have 1 neutral leg. If the hot legs are not 180 degrees out of phase then the neutral carries all return current instead of just the unbalanced return current. I didn't even think about that until Chance's post above triggered my brain.

Sure would be nice if Onan built their generators to industry standard split-phase windings instead of in phase windings. I don't understand why they do that.

[dkoldman]

Originally Posted by 16ACE27

L14-30 can handle up to 7500 watts at 240 VAC but only half that at 120 VAC even if you do have two hot because you only have 1 neutral leg. If the hot legs are not 180 degrees out of phase then the neutral carries all return current instead of just the unbalanced return current. I didn't even think about that until Chance's post above triggered my brain.

Sure would be nice if Onan built their generators to industry standard split-phase windings instead of in phase windings. I don't understand why they do that.

Ok some let me translate to see if I follow.

1. I will need to select one of my two 30 amp circuits from generator
2. I will need to run a jumper on the L14 - 30R receptacle; so the one hot lead I have will be on the X & Y wires on my 30 amp cord. The Ground and Neutral like normal.
3. This will basically be equivalent of what my Portable 3500 does, I will still have 30 amps max or 3750 watts max
4. But on the flip side, if it power outage and genset is running feeding the house; if I know what all is on the other 30 amp breaker not connected to genset, I should be able to use it like normal? i.e. I find out which one controls the charger, microwave, and which AC etc?