Generator question when we have a power outage

[757driver]

Originally Posted by ronlin11

Having replaced two transfer switches in my 2014, I do not believe it has the capacity to switch automatically from generator to shore. If it is plugged in to 50 amp shore power it will not trip the breaker when both are on. If plugged into 20 or 30 amp I believe it will trip the breaker. I base this on my 06 Diplomat that had the same type of transfer switch and was plugged into 20 amp at home. I started the generator and it immediately tripped the 20 amp breaker. I can not see how my current coach is any different but note that the newer coaches may be more sophisticated.

Mine is a 2014 as well and I do not trip any breakers when the transfer switch switches power. Was that circuit that you were plugged into at home when it tripped a gfi plug? That may be the cause.

[Matt D]

JH, admittedly I didn’t flip on the shore breaker with A/Cs operating, knowing that the contactors are not Full Load Rated. What you are saying makes sense.

Bob, thanks for sharing the cool down suggestion. Frankly, I’ve never given either of our generators a thought as to cool down.



-Matt

[BobG88]

Originally Posted by Matt D

JH, admittedly I didn’t flip on the shore breaker with A/Cs operating, knowing that the contactors are not Full Load Rated. What you are saying makes sense.

Bob, thanks for sharing the cool down suggestion. Frankly, I’ve never given either of our generators a thought as to cool down.



-Matt

No problem Matt - I was the same as you before our problem. The region manager said a large % of similar repairs would very likely be traced back to lack of cool-down (did make sense when I thought about it...). Thanks,

BG

[ronlin11]

When looking at my transfer switch, if plugged in it will make the shore power side of the switch push in and connect. If the generator is turned on the generator side will push in and connect. These are the two inputs coming into the transfer switch. There is only one output going to the breaker switches as the two outputs are wired together. As my 06 Diplomat was plugged into home 20 amp and I started the generator the 50 amp surge traveled thru the power cord and tripped the 20 amp breaker at the box. Having worked on two transfer switches on my 14 coach, I doubt if it is capable of automatically switching thus turning off the outside electrical input to switch to generator. Now if you are plugged into 50 amp then a 50 amp surge will not trip the breaker. With my coach I will not start the generator when I am plugged into shore power. Other coaches may be capable of doing this but I certainly would not trust mine.

[twinboat]

Originally Posted by ronlin11

When looking at my transfer switch, if plugged in it will make the shore power side of the switch push in and connect. If the generator is turned on the generator side will push in and connect. These are the two inputs coming into the transfer switch. There is only one output going to the breaker switches as the two outputs are wired together. As my 06 Diplomat was plugged into home 20 amp and I started the generator the 50 amp surge traveled thru the power cord and tripped the 20 amp breaker at the box. Having worked on two transfer switches on my 14 coach, I doubt if it is capable of automatically switching thus turning off the outside electrical input to switch to generator. Now if you are plugged into 50 amp then a 50 amp surge will not trip the breaker. With my coach I will not start the generator when I am plugged into shore power. Other coaches may be capable of doing this but I certainly would not trust mine.

Auto transfer switchs have mechanical lockouts preventing both contractors from closing.

I don't pretend to know what happens to your switchs but ATS's don't back feed the shore cord when they switch to generator. That would cause the shore cord to be energized and a shock hazard.

Here is a link with operation description.

https://www.progressivedyn.com/rv/au...tch/#downloads

[hdgoldie]

May I please clarify the cool down being discussed? We typically run with our generator on and, usually, all three A/C units powered. When we stop for fuel the first thing I do is to turn off the cooling system and then turn off the generator before Rick starts the fueling process. Are you saying that I should be turning off the A/C's at least 15 minutes in advance of turning off the generator? We do the same process if we pull into a campground and discover gravel roads. Turn off A/C's and then generator so that we aren't throwing dust all over while getting to our campsite. Rick hooks up power first and, once the surge protector finishes it's check, we get the air back on and then finish setup. When it's in the 90's outside, a 15 minute cool down would result in a really warm coach. Am I misunderstanding the recommendation?

[Matt D]

Linda, I think you’re reading the suggestion correctly.

-Matt

[757driver]

Here is what Cummins Onan recommend in their manual and not a service tech or managers opinion. Do as you wish but I think 15-30 minutes cool down is rather excessive.

Starting And Stopping Procedures

Your Cummins Onan generator can be started and stopped from the integral control panel on the generator, or from the optional remote control panel inside the vehicle if your RV is so equipped. Your Operator's Manual outlines the simple steps for starting and stopping. Remember to: • Before starting the generator, turn off air conditioners and large electrical loads. • Before starting in cold weather, turn off all appliances for best long-term performance. • Prime by holding stop (all Quiet Diesels, Quiet Gas 3600-7000). • To start - press and hold start at the control panel or at the set. - Quiet Diesel: auto pre-heat flash, then crank/start - Don't over-crank with no start • Before turning on appliances, let the generator warm up for a few minutes. • Turn off air conditioners and large electrical loads and allow the generator to run for 3-5 minutes before stopping, to allow the generator to cool down.

[brobox]

Linda as others are saying 15 minutes is overkill, what Don posted from the manual is what we do. Most is on the 3 minute side depending on temps and how hard we have been running the generator. We don't travel with #3 A/C on as nobody is back there and # 2 only if it is exceptionally hot, not knowing where your dogs ride you may use #2. The less demand on the generator the quicker the cool down cycle. One Onan tech told me 2 minutes if just running one AC.


As for the transfer switch others have talked about, I don't trust them to work perfectly as too many have needed replacing. JMO, I don't think they do well with the double loads. I shut shore power off first, then start the generator. Shutting down generator, let generator cool down, then reverse. Knock on wood I have not had to replace a transfer switch. It has worked for me through 3 coaches, so I will continue with that practice, but that is just me.

[BobG88]

I'm certainly the farthest thing from an "expert", and again, this is not my suggestion, but from our Onan region manager.

I told him I was following the manual's suggestion, and his adamant response was what I posted above.

Is it excessive - possibly; however, the repair would have cost us >800.00 if not under warranty, so I do my best to at least follow the 15 minute suggestion. Thanks,

BG

[Gary.Jones]

Bob

Just my humble opinion and my experience now in 3 coaches over ~ 5-6 years....

15 minutes is crazy excessive!!

I have a 50 KW whole house natural gas powered Generac that powers my whole house in a hurricane. Turns itself on and turns itself off. Water cooled Ford Engine. When commerial power is lost, it runs/warms itself maybe 30 seconds before it take the whole house 50 KW onto itself through 400 amp transfer switches, and when the commercial power comes back on, the generator runs itself about one minute more and then shuts itself down, and that is from a full 50 KW load. That is the way it is programmed to operate from Generac. That seems pretty clear to me.

I give the Onan a few minutes, but 15 minutes is WAY more than it needs. Of course, YCDWYW

Gary

[ronlin11]

I went thru this discussion when I had my 06 Diplomat with a Monaco group. I was told the same thing that it was not possible for the two sides of the transfer switch to be engaged at the same time. When I started my generator my coach was plugged into a 20 amp outlet in my garage. Not only did it trip the 20 amp breaker (not GFI) at the box but it fried the outlet and it had to be replaced. Again maybe my new 2014 Aspire might not do this but I can not see any difference in the transfer switches so I will continue to use either the shore power or the generator not both at the same time.

[ronlin11]

twinboat,

The switch shown is a Progressive which is a much higher quality switch than the Surge Guard that most have. I would not trust my Surge Guard to automatically switch. To me better to be safe as it is no big deal to have one or the other working not both.

[BobG88]

Originally Posted by Gary.Jones

Bob

Just my humble opinion and my experience now in 3 coaches over ~ 5-6 years....

15 minutes is crazy excessive!!

I have a 50 KW whole house natural gas powered Generac that powers my whole house in a hurricane. Turns itself on and turns itself off. Water cooled Ford Engine. When commerial power is lost, it runs/warms itself maybe 30 seconds before it take the whole house 50 KW onto itself through 400 amp transfer switches, and when the commercial power comes back on, the generator runs itself about one minute more and then shuts itself down, and that is from a full 50 KW load. That is the way it is programmed to operate from Generac. That seems pretty clear to me.

I give the Onan a few minutes, but 15 minutes is WAY more than it needs. Of course, YCDWYW

Gary

I understand and appreciate your comments Gary - it seems to be excessive to me also. However, the guy who told me this was definitely a senior-level guy - it was tough for me to argue with him.

He showed me the parts - they were definitely scoured - and he said lack of cool-down was the cause.

Actually, extending the cool-down time has not been much of a hassle. It may be/probably is unnecessary; however, when convenient, I'll probably continue to error on the side of caution... Thanks again,

BG