RV News RVBusiness 2021 Top 10 RVs of the Year, plus 56 additional debuts and must-see units → ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > RV SYSTEMS AND TECHNOLOGIES FORUMS > RV Systems & Appliances
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 02-23-2016, 09:24 AM   #1
Senior Member
 
Kro1957's Avatar
 
Thor Owners Club
Join Date: Jun 2012
Location: Mitchell South Dakota
Posts: 1,177
Blog Entries: 2
Help!! Advice for electrical issue. Not sure what we did.

Just purchased a 06 class A DP. The unit was plugged into 50a SP and owner fired up the gen before unplugging the SP. Thus, we were pushing power from 2 sources at the same time. I am not sure this is a good idea.

Owner turned on the rear air and in a minute or so we started smelling burning. It was definitely electrical fire! We shut everything down to find the source. We fried the Convection / Microwave!

Owner had never used a protection device so my first investment was purchased one at CW for the SP/50a. Ok, this should take care of that and the other appliances appear to still be working fine. Here are a few questions.

1. What do you think caused this? I am told it is safe to be plugged in and run the gen.

2. The fwd TV/entertainment system is plugged into a standard surge protector which was turned off at the time. Should I just continue to use that device for those electronics?

3. The bedroom set is plugged into standard 110 coach outlet. Should I put a surge protector on that?

4. This new convection/microwave is costly and the previous one we fried was plugged directly into the overhead cabinet 110 outlet with no powerstrip/protector. Is that the SOP? Should I find a protector of some kind and if so give me your recommendations.

Thanks!! James
__________________
06 King of the Road 37RLQS
06 Coachman Cross Country 5.9L 300HP 382 DS
03 Jeep Wrangler, 4.0L James, Trina, SMSgt, USAF Ret
Kro1957 is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 02-23-2016, 09:40 AM   #2
Senior Member
 
Join Date: Sep 2012
Posts: 8,055
FWIW If everything was working correctly it should not make a difference. When the generator is started it runs for roughly a half minute while the engine settles down then turns on the AC. The presence of AC from the generator causes the transfer switch to trip changing the coach internal AC power from the line cord to the generator. That can introduce a very short term power spike that your protection circuit will not catch if it is in the power line from the pedestal to the transfer switch.

If the microwave was on during the transfer then the power spike might have been a problem for the microwave power supply. That might be what the problem was. OTOH that is somewhat of an aberration as there is no good reason to run the generator when AC is available from shore. If one wants to go to generator power under those conditions a wise person would not be running either the A/C, the microwave, or any other high current loads. That is asking for trouble from the switchover spike. It is also detrimental to the transfer switch.
nothermark is offline   Reply With Quote
Old 02-23-2016, 09:54 AM   #3
Senior Member
 
Skip426's Avatar


 
Join Date: Apr 2011
Location: Powell River, B.C.
Posts: 21,713
I've fired up my gen set many times with the coach on shore power; although probably not a great idea, I haven't found anything in the ATS booklet that warns against it ; I would assume the first item to be effected would be the Auto Transfer Switch, then the A/C units if they were turned on with the two sources.

If the Con/Mic fried without being turned on , I would think ; maybe ; some kind of cleaner or fluid from cleaning got in somewhere it shouldn't have been.

A previous owner had installed a single circuit surge guard at the C/M outlet in my coach, and I've continued to use it, and have installed a hardwired 50 amp protector in the shore power for the coach.
If your entertainment systems are powered from an inverter as well as shore power then an additional surge bar would be a good idea.
__________________
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.
Skip426 is offline   Reply With Quote
Old 02-23-2016, 10:04 AM   #4
Senior Member
 
Join Date: Jul 2014
Posts: 25,494
Like others had said, the transfer switch will not let 2 power sources go past it, so that shouldn't be a factor.

If the oven or an AC or 2 were running when it switched, then a drop then surge in power could fry stuff.

One other thing to check would be the output voltage on the generator. If it is running too fast, the volts go up.
twinboat is online now   Reply With Quote
Old 02-23-2016, 10:27 AM   #5
Senior Member
 
ernieh's Avatar
 
Join Date: Jul 2009
Posts: 1,370
If your coach has a MSW inverter, there's a good chance that it's what fried your microwave. Things with timers and MSW frequently don't play well.
__________________
ernieh
2019 Phaeton 37BH
ernieh is offline   Reply With Quote
Old 02-23-2016, 10:36 AM   #6
Senior Member
 
CampingCajun's Avatar
 
Join Date: Jul 2014
Location: Lafayette, La.
Posts: 1,144
The transfer switch may be bad. I always unplug from SP before cranking the genie or kill the genie before plugging into SP. Old habit from switching Industrial type generators (had to wait for everything to equalize before switching).
__________________
2011 40' Monaco Cayman PBQ ISC 360
2013 Jeep Wrangler Unlimited
CampingCajun is offline   Reply With Quote
Old 02-23-2016, 10:43 AM   #7
YC1
Senior Member
 
YC1's Avatar


 
Holiday Rambler Owners Club
Join Date: Jun 2011
Posts: 8,415
Find out what transfer switch you have. There was a recall on certain models. Caused several fires.
__________________
Myron & Deborah
08 HR Endeavor 40 SKQ
2016 Ford F150 Limited V6 with Ready Brake
Aluminator tow bar, Demco base plate
YC1 is offline   Reply With Quote
Old 02-23-2016, 10:52 AM   #8
Senior Member
 
Join Date: Sep 2012
Posts: 8,055
Quote:
Originally Posted by ernieh View Post
If your coach has a MSW inverter, there's a good chance that it's what fried your microwave. Things with timers and MSW frequently don't play well.
The microwave should not be running off the inverter if switching between shore and generator power.
nothermark is offline   Reply With Quote
Old 02-23-2016, 03:47 PM   #9
Senior Member
 
Join Date: Sep 2013
Posts: 286
It really doesn't matter if the microwave was "on" when the generator was fired up. The controller in the microwave is always powered up (the buttons turn on displays and operate the heating elements (microwave or convection) but it is always alive when power is applied. I never run both shore power and the generator at the same time.

The transfer switch is only supposed to connect one at a time, but when it decides to switch the two sources aren't synchronized so you can go from the positive peak of one source to the negative peak of the other. That is an instantaneous swing of about 300 volts into everything connected to the AC lines. It's no different than the normal swing as far as voltage is concerned, but it happens in microseconds instead of milliseconds.

I suspect that is what fried the microwave. It's also the reason I avoid running both shore power and the generator at the same time and letting the transfer switch decide to swap inputs. It's a high stress change over if both are running. Your mileage may vary.
__________________
Jim (NQ5L) & Chris
2007 Monaco Knight 40 PDQ
2011 Jeep Liberty
jrusselltx is offline   Reply With Quote
Old 02-23-2016, 05:06 PM   #10
Senior Member
 
Kro1957's Avatar
 
Thor Owners Club
Join Date: Jun 2012
Location: Mitchell South Dakota
Posts: 1,177
Blog Entries: 2
Transfer switch fried !!

Transfer switch fried! Model ATS 5070

Progressive Dynamics Inteli-Power 9200 Series Converter/Charger seems to be ok.

Lesson here... I think never chance firing up the gen-set while hooked to SP even though it is supposed to not hurt anything. We are talking electricity and components and in my mind that push from both ends can and I believe in this case caused some very expensive repairs.

Just glad it did not fry anything else.

lastly, should I put some kind of protection device on the convectionwave oven where it plugs into 110 outlet?

Thanks for all the advice!! James
__________________
06 King of the Road 37RLQS
06 Coachman Cross Country 5.9L 300HP 382 DS
03 Jeep Wrangler, 4.0L James, Trina, SMSgt, USAF Ret
Kro1957 is offline   Reply With Quote
Old 02-23-2016, 10:25 PM   #11
Senior Member
 
Fred and Bonnie's Avatar
 
Workhorse Chassis Owner
Join Date: Jan 2002
Location: Pacific Northwest or SoCal
Posts: 3,015
Send a message via ICQ to Fred and Bonnie
I make it a habit to remove heavy loads when switching between the two systems.


Fred
__________________
Fred and Bonnie
2005 Dolphin LX 6375
Abby, Ruffles & Scarlett, "The Cats"
Fred and Bonnie is offline   Reply With Quote
Old 02-24-2016, 06:09 AM   #12
Senior Member
 
Join Date: Sep 2012
Posts: 8,055
Switching heavy loads is the problem, not just switching. The current spike when the out of phase power is applied causes the damage.

If the ATS still works then there is no reason to replace it. It is a dumb relay that does not monitor phase angle or worry about matching phases. Neither does the generator controller. It is not an issue for normal operation of starting and using the generator when there is no shore power available. The only reason to protect against it would be if someone was making a habit of being stupid as opposed to making a mistake.
nothermark is offline   Reply With Quote
Old 02-24-2016, 06:14 AM   #13
Senior Member
 
Pullin' Chocks's Avatar
 
New Horizons Owners Club
Join Date: Aug 2011
Posts: 472
The Shore ground should be removed when running the generator. The coach chassis becomes ground when running the genny. We always unplug and make sure the ground pin is not touching the ground or any water on the ground.
__________________
2013 New Horizons 37' Majestic 5th Wheel
2018 Ram 5500 Laramie Custom, Full-Timers since 2013
https://pullinchocks.blogspot.com/
Pullin' Chocks is offline   Reply With Quote
Old 02-24-2016, 07:23 AM   #14
Senior Member
Commercial Member
 
Join Date: Aug 2012
Posts: 726
In all areas of the U.S. Isolation of the generator and the shore cable is required by code to protect the electrical distribution system from back feeds. Your transfer switch serves this purpose and when properly installed and working will cause no harm under these conditions. Many RV manuals actually call for this when doing monthly generator exercises.

The fault or potential problem is starting the generator or connecting the shore cable under load. In all cases, the breakers should be off until connections are made, transfer has happened and so on. If not, all sorts of spikes, noise, transients, and potential problem situation can cause subsequent problems.

While many will say this is not a good practice, the system is designed to be foolproof and not cause any problem that were operator injected, assuming everything is working correctly.


Sent from my iPad using iRV2 - RV Forum
TravellingRVDoctor, LLC
__________________
Traveling RV Doctor
https://www.facebook.com/Traveling-R...5780632151951/
shiggs68 is offline   Reply With Quote
Reply

Tags
advice, electrical



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Deposit down- Now I'm not sure I can tow it. manual not clear l2yangop Travel Trailer Discussion 32 12-02-2015 08:40 PM
Electrical dead, not sure why.. ozzy Larsen RV Systems & Appliances 14 08-03-2014 08:37 AM
Repair shops not to go to / If you list a shop here make sure it is not just a grudge GlennLever Class A Motorhome Discussions 1 02-04-2014 11:22 AM
Not Sure If this is a Good Thing or not. chaunclm New Horizons Owners Forum and NHOG 1 10-29-2010 08:48 PM
Not sure whether to waste my time or not Steve,N,Jan Excel Owner's Forum 4 03-27-2009 08:44 PM


All times are GMT -6. The time now is 04:16 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.