Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: jeff on January 02, 2011, 02:34:38 pm
Title: lost power to 1/2 coach
Post by: jeff on January 02, 2011, 02:34:38 pm
Sitting in FOT parking lot, luckily..This A.M. we were using a lot of power..two heaters, tv, microwave, coffee pot, etc. when we lost power and automaticly switched to inverter.
Switched power poles here at camp. Switched to 30 amp cord. Ran generator...no matter, still 1/2 coach is off. All work for approx one minute before cutting off. Everything runs off inverter. No circuits have been tripped. I can turn off power at pole and turn back on in 10 seconds and coach is fully powered fot that short while.
I am NOT an electician so please remember that in your reply...Next I will break out the manual.
Have unplugged micro-wave,, coffee pot, turned off all heaters, etc. Same results...
I am lost for other things I can check..
Thanks, all
Title: Re: lost power to 1/2 coach
Post by: Bob McGee on January 02, 2011, 02:36:21 pm
Deleted
Title: Re: lost power to 1/2 coach
Post by: Michelle on January 02, 2011, 02:48:29 pm
Sitting in FOT parking lot, luckily..This A.M. we were using a lot of power..two heaters, tv, microwave, coffee pot, etc. when we lost power and automaticly switched to inverter.
Switched power poles here at camp. Switched to 30 amp cord. Ran generator...no matter, still 1/2 coach is off. All work for approx one minute before cutting off.
Jeff,
Steve and I are discussing - since you have the same issues with the generator but not the inverter it sounds like it might be a relay in the transfer switch going bad on one leg (if that's possible). Since it works ok for about a minute, it almost sounds like a heating issue within the switch - an electrical connection opening up as it heats.
Michelle
Title: Re: lost power to 1/2 coach
Post by: jeff on January 02, 2011, 02:52:24 pm
Believe you are correct. Now I just have to find the transfer case...so many new things to find on a newer coach..
Anyone know where the transfer case is for a u320 1995 ? Probably looked at a dozen times, but it didn't bite me so didn't pay attention...
Happy New Year all
Title: Re: lost power to 1/2 coach
Post by: Bob McGee on January 02, 2011, 02:56:35 pm
Should be under the bed.
Title: Re: lost power to 1/2 coach
Post by: Barry Beam on January 02, 2011, 03:02:12 pm
Believe you are correct. Now I just have to find the transfer case...so many new things to find on a newer coach..
Anyone know where the transfer case is for a u320 1995 ? Probably looked at a dozen times, but it didn't bite me so didn't pay attention...
Happy New Year all
After you find the transfer switch, here is what a burned relay looks like and how to replace it. Replacing a Transfer Relay (http://www.beamalarm.com/Documents/replacing_a_transfer_relay.html)
Title: Re: lost power to 1/2 coach
Post by: Kent Speers on January 02, 2011, 03:06:07 pm
Sitting in FOT parking lot, luckily..This A.M. we were using a lot of power..two heaters, tv, microwave, coffee pot, etc. when we lost power and automaticly switched to inverter.
Switched power poles here at camp. Switched to 30 amp cord. Ran generator...no matter, still 1/2 coach is off. All work for approx one minute before cutting off.
Jeff,
Steve and I are discussing - since you have the same issues with the generator but not the inverter it sounds like it might be a relay in the transfer switch going bad on one leg (if that's possible). Since it works ok for about a minute, it almost sounds like a heating issue within the switch - an electrical connection opening up as it heats.
Michelle
That was my first thought too but if it were one side of the main transfer switch it would only affect 220V operation. Since the inverter supplied power is not affected, it almost has to be in the control switch for the Shore Power/Inverter Power but Jeff can't find the location of the control switches.
Title: Re: lost power to 1/2 coach
Post by: Barry Beam on January 02, 2011, 03:45:04 pm
Sitting in FOT parking lot, luckily..This A.M. we were using a lot of power..two heaters, tv, microwave, coffee pot, etc. when we lost power and automaticly switched to inverter.
Switched power poles here at camp. Switched to 30 amp cord. Ran generator...no matter, still 1/2 coach is off. All work for approx one minute before cutting off. Everything runs off inverter. No circuits have been tripped. I can turn off power at pole and turn back on in 10 seconds and coach is fully powered fot that short while.
I am NOT an electician so please remember that in your reply...Next I will break out the manual.
Have unplugged micro-wave,, coffee pot, turned off all heaters, etc. Same results...
I am lost for other things I can check..
Thanks, all
If you are saying that all circuits will work on the inverter and half will not work on 110vac no matter where it comes from. Than look at the diagram below. It shows 2 transfer switches. The second one is fed by 110vac & the other input is the inverter. So it looks like one relay in that transfer switch is working and the other is not. The points on the relay could be pitted and might be able to use a small burnishing blade to file it a little so it will make contact. BUT there is 110 voltage there and if you are not familiar with removing ALL power to it. Leave it for someone experienced.
Title: Re: lost power to 1/2 coach
Post by: Michelle on January 02, 2011, 03:55:01 pm
since you have the same issues with the generator but not the inverter it sounds like it might be a relay in the transfer switch going bad on one leg
That was my first thought too but if it were one side of the main transfer switch it would only affect 220V operation. Since the inverter supplied power is not affected, it almost has to be in the control switch for the Shore Power/Inverter Power
I looked (am looking) at our schematics to see if there's any insight to be gleaned. At least in our coach, only leg #2 of the main power from the main transfer switch/relay is passed to the Shore Power/Inverter Power transfer switch (relay #2). Only 3 circuits are powered by the inverter, and because of the wiring, they are all on leg #2 of the main power. There are still a few on leg #2 that aren't inverter powered and then the rest are powered by leg #1 of the main power.
I guess the question would be which circuits are working or not working on either shore or generator - all on leg #1, all on leg #2, or just those which are run of the inverter (which are possibly/probably only on one leg of the 220V)? From there we might be able to narrow it down some more.
Michelle
Title: Re: lost power to 1/2 coach
Post by: Dave M (RIP) on January 02, 2011, 05:15:18 pm
Michelle, I think the first step would be to determine what is not working, seems that would be a simple starting point. Back read the wiring diagram, bingo the big picture appears. Enjoy Dave
Title: Re: lost power to 1/2 coach
Post by: jeff on January 03, 2011, 09:51:19 am
Just in case anyone thinks I might have any intelligence FOT fixed my power problem this A.M. After spending a couple hours checking circuits, breakers, etc. I gave up. The problem was on the 2500 heart interface box..tripped the button which controls the transfer(I was probably in that bay 6-8time)...well, at least I learned a whole lot more about this "new to us" coach and how to read schematics..AND a hearty thanks to all who helped, you the best.
Title: Re: lost power to 1/2 coach
Post by: Barry Beam on January 03, 2011, 10:06:37 am
Just in case anyone thinks I might have any intelligence FOT fixed my power problem this A.M. After spending a couple hours checking circuits, breakers, etc. I gave up. The problem was on the 2500 heart interface box..tripped the button which controls the transfer(I was probably in that bay 6-8time)...well, at least I learned a whole lot more about this "new to us" coach and how to read schematics..AND a hearty thanks to all who helped, you the best.
Jeff, I am not sure how that prevents losing power on half the ckts. when you are on incoming shore power. Can you tell me a little more.
Title: Re: lost power to 1/2 coach
Post by: Carol Savournin on January 03, 2011, 03:04:06 pm
On the Heart Interface box in the bay there are 3 breaker "buttons" that each have "30" on them. One says Charger, one Transfer and the bottom says Output. The Transfer breaker was popped out ... and the difference between in and out is not huge, apparently, because Jeff missed it. When plugged into shore power or when running the the generator the TVs, Microwave, all AC outlets and elec heaters were dead. the only things that worked were the lights and the elec toilet (thank goodness!). What appeared to be "half" the coach was not, in reality, just one leg. I don't speak Electric ... so I am not the best person to be describing this. After getting the batteries charged up and using the inverter, everything worked just fine. It HAD to be something simple ... but we figured that if all the breakers we could find were good, it had to be something We are feeling a bit OMG at the moment ... but this is a whole new learning curve. We are gonna do things that are a lot dumber, I guarantee!
Title: Re: lost power to 1/2 coach
Post by: J. D. Stevens on January 03, 2011, 06:12:52 pm
If the lights and toilet were all that worked, you probably lost ALL of you 120VAC power. That's the "big volts" you get from generator, shore power, and inverter. The lights and toilet (I who have a manual toilet am guessing) would run on 12VDC. That's what comes directly from the batteries.
Title: Re: lost power to 1/2 coach
Post by: Pierce & Gaylie Stewart on January 04, 2011, 02:11:17 pm
I lost power to half the coach and spent a couple of hours trying to trace the problem. I put stronger glasses on and discovered the GFI above the bathroom sink had tripped. Could not see it because both buttons are the same brown color as the plug. No fool like a blind fool.
Pierce & Gaylie 93' U300/36
Title: Re: lost power to 1/2 coach
Post by: Russell on January 04, 2011, 04:55:55 pm
I likewise had a similar problem two years ago. The problem was none of the above. It turned out to be a broken contact coming directly off of the generator. Like you Jeff, I'm limited on what I can do, so I had to take to a Cummins Coach Care facility in the NE. They were able to track down the problem and fix it w/o too much of a hassel.