Bighorn - AC Power Not Working

[rednag564]

My mod 3185Rl Big Horn 5th wheel has no AC power inside.. I borrowed someone else's cable and it worked for a few weconds, then suddenly no AC power. A tech once told me there was a "Master Shutoff", but I failed to ask where.

The AC ckt breakers were reset and should be functional.

When I normally plug in the AC, I hear a click from somewhere in the rear of the trailer. Now when I plug in the AC, there is no click..

Can anyone help me..

Thanks..

Gary Anderson

 

[jimtoo]

Re: ATF: Bighorn - AC Power

Hi Gary,

Welcome to the Heartland Owners Forum and to the family. We have a great bunch of folks here with lots of information and all willing to share their knowledge when needed.

We need a little more info about your unit. What year is your Big Horn, do you have generator prep? When you hooked to trailer outlet, did you turn the plug to make good contact? Does the unit have a built in surge protector?

Please add a little more info for us.

Jim M

 

[Jim.Allison]

Re: ATF: Bighorn - AC Power

I dont know why I do it but I always cycle the breakers. Like I said there is no logical reason with your symptoms but that would be the first thing I would do. We have all found breakers that were thrown that did not appear to be thrown, I have found that to truly determine if a breaker is engaged, you have to cycle it. Sometimes they do not throw all the way ( you say the breakers are engaged). That having been said. You gotta get us the info that Jimtoo is asking for.

But you might also cycle the breakers at the shorepower. Then check what you are getting off that cable, 120v on each leg to both ground and neutral and either 240v or 120v across the two 120v legs, either reading is ok between the two hot legs.

All I can think of right now. I would not bet money unless I had to, but if I were to make a bet, I'm going with shorepower is bad.

My mod 3185Rl Big Horn 5th wheel has no AC power inside. I borrowed someone else's cable and it worked for a few weconds, then suddenly no AC power. A tech once told me there was a "Master Shutoff", but I failed to ask where.

The AC ckt breakers were reset and should be functional.

When I normally plug in the AC, I hear a click from somewhere in the rear of the trailer. Now when I plug in the AC, there is no click..

Can anyone help me..

Thanks..

Gary Anderson

 

[danemayer]

Re: ATF: Bighorn - AC Power

The click you used to hear might be the transfer switch, if you have generator prep. But the transfer switch is usually mounted in the front, behind the basement wall, close to the backside of the circuit breaker box.

The transfer switch contactor actuates if there is 120V on the L1 line coming in from the pedestal.

I'd suggest finding someone with a voltmeter to check the voltage at the pedestal for starters. It's not all that unusual to have a problem there.

Also, in the summer, if your location is hot, the voltage at the pedestal could drop below acceptable levels intermittently. Someone else had that problem at a campground in Texas recently.

The master cutoff is 1) the circuit breaker on the outside pedestal, 2) the leftmost 2 breakers in your circuit breaker box. These are the 2 50 amp breakers that feed everything else in the circuit breaker panel.

Sent from my iPad using Tapatalk HD

 

[Jim.Allison]

Re: ATF: Bighorn - AC Power

In the gen prep the transfer switch is locked into the shorepower position. When the generator is installed the lockout is removed. -just adding to your statement.

The click you used to hear might be the transfer switch, if you have generator prep. But the transfer switch is usually mounted in the front, behind the basement wall, close to the backside of the circuit breaker box.

The transfer switch contactor actuates if there is 120V on the L1 line coming in from the pedestal.

I'd suggest finding someone with a voltmeter to check the voltage at the pedestal for starters. It's not all that unusual to have a problem there.

Also, in the summer, if your location is hot, the voltage at the pedestal could drop below acceptable levels intermittently. Someone else had that problem at a campground in Texas recently.

The master cutoff is 1) the circuit breaker on the outside pedestal, 2) the leftmost 2 breakers in your circuit breaker box. These are the 2 50 amp breakers that feed everything else in the circuit breaker panel.

Sent from my iPad using Tapatalk HD

 

[rednag564]

Thanks for the prompt responses.. First off, it's a 2011 3185RL. The equipment list doesn't mention a built-in surge protector. It is Gen prepped however. I do NOT have continuity from the Shore power input to the AC ckt breaker panel. Excluding the surge protector, it appears the likely culprit may be the Gen. prep.. I sure wish I had a wiring diagram or schematic of this trailer..

 

[danemayer]

If the transfer switch is not actuated, the circuit between the pedestal and circuit breaker panel is open, so you would read no continuity. Jim A commented that if there's no generator, the transfer switch would be locked down for shore power - presumably with a mechanical device so it doesn't need to actuate the contactor. But when I replaced my transfer switch (several times), none of them came with any kind of lockdown device, so I'm not sure what you should expect there.

Next step is to take down the basement wall to get to the transfer switch. Location may vary a bit by floorplan, but it's probably behind the doorside section.

I CAN'T EMPHASIZE ENOUGH THE NEED FOR EXTRAORDINARY CARE WHEN WORKING WITH THE TRANSFER SWITCH. MAKING A MISTAKE COULD BE FATAL.

On one end of the transfer switch, there's a single cable. That end goes to the circuit breaker panel. Directly across at the other end of the box is the shore power input cable. Next to the shore power input is the generator input cable.

With the power cord unplugged from the pedestal, you can safely open the transfer switch enclosure (one hex screw). If you manually depress the contractor assembly on the shore power side, (UNPLUGGED FROM THE PEDESTAL) you should read continuity across the switch.

If you are very careful, you can leave the cover off the enclosure and plug into shore power. There's a wiring diagram on the inside of the cover that shows L1, Neutral, and L2. With power applied, measuring the input side should read 120V between L1 and Netural, and also between L2 and neutral. You might also check between the hot wires and ground to make sure you don't have a bad neutral. Normally if you read 120V between L1 and neutral, you would also read 120V between L1 and ground. If there's any significant difference, you might need to investigate further.

If the voltage is correct on the input side, and the transfer switch is working, you should read the same on the output side, and at the circuit breaker panel.

If voltage is low on L1 for any reason, say below 105V, the contactor may not actuate and the coach will not get power.

If the contactor doesn't actuate, or has contacts that aren't conducting power properly, that would explain your problem and you'll likely need a new transfer switch. About $150.

It's a pain to install a new switch because you'll be lying on your side with feet hanging out the hatch. It's hard to reach the parts and the #6 wire is difficult to work with. Paying $100-200 for someone else to do the work might be worthwhile.

If you do it yourself, before powering up the coach with the new switch, turn off all circuit breakers except for one that feeds only outlets. Don't have anything plugged in to the outlets. Test the readings at the outlet to make sure you didn't get wires mixed up. If you made a mistake, this should keep you from frying all your equipment.

 

[Jim.Allison]

Just to contribute. My gen prep had a yellow lock out installed on the transfer switch. I burned up my transfer switch upon my generator installation by starting the generator, the lockout prevented the transfer switch from transferring from the shore power position (SP not hooked up at the time). I ordered the identical transfer switch to replace, it had no lockout with it. I taped the bright yellow lockout to a pipe behind the basement wall in the event that I need it in the future. This should not enter into the OP's problem unless he has done a generator install, or perhaps the lockout was inadvertently installed or someone failed to remove it. Otherwise the lockout scenario is a mute issue for him. But if he opens his transfer switch and there is a bright yellow block across the contacts locking down the shore power contact and he has a generator, then there is a major problem. Of course if the OP has been successfully using his rig on generator and shore prior to this problem the block cannot be an issue.

If the transfer switch is not actuated, the circuit between the pedestal and circuit breaker panel is open, so you would read no continuity. Jim A commented that if there's no generator, the transfer switch would be locked down for shore power - presumably with a mechanical device so it doesn't need to actuate the contactor. But when I replaced my transfer switch (several times), none of them came with any kind of lockdown device, so I'm not sure what you should expect there.

Next step is to take down the basement wall to get to the transfer switch. Location may vary a bit by floorplan, but it's probably behind the doorside section.

I CAN'T EMPHASIZE ENOUGH THE NEED FOR EXTRAORDINARY CARE WHEN WORKING WITH THE TRANSFER SWITCH. MAKING A MISTAKE COULD BE FATAL.

On one end of the transfer switch, there's a single cable. That end goes to the circuit breaker panel. Directly across at the other end of the box is the shore power input cable. Next to the shore power input is the generator input cable.

With the power cord unplugged from the pedestal, you can safely open the transfer switch enclosure (one hex screw). If you manually depress the contractor assembly on the shore power side, (UNPLUGGED FROM THE PEDESTAL) you should read continuity across the switch.

If you are very careful, you can leave the cover off the enclosure and plug into shore power. There's a wiring diagram on the inside of the cover that shows L1, Neutral, and L2. With power applied, measuring the input side should read 120V between L1 and Netural, and also between L2 and neutral. You might also check between the hot wires and ground to make sure you don't have a bad neutral. Normally if you read 120V between L1 and neutral, you would also read 120V between L1 and ground. If there's any significant difference, you might need to investigate further.

If the voltage is correct on the input side, and the transfer switch is working, you should read the same on the output side, and at the circuit breaker panel.

If voltage is low on L1 for any reason, say below 105V, the contactor may not actuate and the coach will not get power.

If the contactor doesn't actuate, or has contacts that aren't conducting power properly, that would explain your problem and you'll likely need a new transfer switch. About $150.

It's a pain to install a new switch because you'll be lying on your side with feet hanging out the hatch. It's hard to reach the parts and the #6 wire is difficult to work with. Paying $100-200 for someone else to do the work might be worthwhile.

If you do it yourself, before powering up the coach with the new switch, turn off all circuit breakers except for one that feeds only outlets. Don't have anything plugged in to the outlets. Test the readings at the outlet to make sure you didn't get wires mixed up. If you made a mistake, this should keep you from frying all your equipment.

 

[Jim.Allison]

Just to be clear, what I'm referring to is what looks like a laser cut or machined piece of yellow nylon block. It is about 6 inches long, 2 inches wide, it slips into the top of the switches, on the generator switch there is a cutout that allows the generator switch to remain open, but on the shore power side the plastic is not cut away and in this manner holds the shore power switch in the engaged position. I cannot say if this is a part provided to Heartland for transfer switches destined for gen prep packages or if it is a device designed by heartland for the transfer switch destined for gen prep packages. Clearly it must be removed if a generator is installed, but I cannot say what its significance is even in the absence of a generator.

As far as the OP is concerned, if he has no generator then he can just buy a junction box and remove the transfer switch in favor of a direct connection. That way he can avoid what I like to call a "RV yoga session"

For what its worth now you guys now know all about the little yellow lockout.....LOL it probably means nothing to this problem.