IMPORTANT: Inspect your inverter wiring. Missing Chassis Ground cable.

[John E Davies]

You’re better off putting a lug with the correct size hole on there. READ THIS From Xantrex before adding washers to the terminal. OK if it’s between the nut and the lug but not between the lug and the terminal.

 

Randy, you are entirely correct, that was a big brain fart on my part. I edited my post. I suppose a pure copper flat washer might be acceptable, but those are not exactly common....

 

Thank you for the correction.

 

John Davies

 

Spokane WA

[RnA]

Thanks John.   I appreciate you pointing out the inverter grounding issue to everyone as well as the issue with the wire run to the ground buss.  I'm looking at my options for changes I will be making to the grounding approach and will post them when I complete them.  - Randy

[MDuncan]

Dear Oliver Owners,

 

Oliver Travel Trailers thanks you for bringing this to our attention. We are in the process of developing a set of inspection guidelines and repair procedures. A technical service bulletin will be released shortly. We wanted to let everyone know that we are aware of the issue and that we are working to resolve this as soon as possible. We will notify everyone with more information once we have developed the inspection guidelines and repair procedure. Thank you again for bringing this to our attention.

[John E Davies]

Dear Oliver Owners,

 

Oliver Travel Trailers thanks you for bringing this to our attention. We are in the process of developing a set of inspection guidelines and repair procedures. A technical service bulletin will be released shortly. We wanted to let everyone know that we are aware of the issue and that we are working to resolve this as soon as possible. We will notify everyone with more information once we have developed the inspection guidelines and repair procedure. Thank you again for bringing this to our attention.

 

 

FYI everyone, the bulletin just came out. Check your email.

 

Matt, your Bulletin contains a couple of serious errors, I Messaged you about them!

 

I am glad that there has been prompt action on this safety issue. Those of us that fixed this ourselves - must we have a stupid RV worker bee inspect the work to get the Oliver Tech bulletin signed off? I would like to be reimbursed for just the materials used, is that possible? My labor was free.

 

Thanks.

 

John Davies

 

Spokane WA

[Overland]

John, I must have missed your earlier reply about not having a fuse block or disconnect.  IMO, I don't think the ground is worth much without a fuse to blow.  12v is unlikely to shock anyone unless they're soaking wet, but a short is absolutely a fire hazard on a high amperage unfused circuit.  So adding a heavy gauge ground and giving any short a nice clean path straight back to the battery may actually increase the risk of fire, unless you add a fuse to your battery bank.  That is, at the moment, your ground wire is also the fuse.

 

If you can verify that you don't have a fuse, then I suggest you get one of these and a spare fuse, and install it on the positive side of the circuit as close to the batteries as possible.  I'd guess on a 2000w inverter that a 300a fuse would be fine, perhaps even 200a, though I don't know the max draw of your inverter.  I have a 400a fuse on mine, with a 3000w inverter, and that was the size fuse that AM Solar recommended to me.  While you're at it, you may as well add a disconnect switch just after the fuse.

 

I think Oliver should amend their TSB to include the installation of a fuse along with the ground cable.

[MDuncan]

John,

Thank you for bringing the flat washer issue to our attention. We receive the inverters from Xantrex with two flat washers, one lock washer and the nut installed on the chassis ground terminal. I personally called one of the engineers at Xantrex and he informed me that you are correct and that the lug or ring terminal should not have a flat washer under it. The ring terminal should be in contact with the chassis. He did however say that if it does have the flat washer under the terminal on the chassis ground, it should not be an issue since there is not much or any voltage drop. He said it would be more of an issue there was a flat washer under the battery ground. In any case, we want it to be properly installed and safe for our owners.

 

According to Xantrex, they are shipped with the two flat washer in the case where someone would be connecting bare wire.

 

I will update the Technical Service Bulletin and resend to everyone. I will also be updating that when a ground wire is present, to check that the appropriately-sized lug or ring terminal was installed and the corrective action if a flat washer is installed between the ring terminal and chassis.

 

Please note that we are required to request all owners that receive this bulletin to have the missing or improperly installed ground wire inspected by a qualified RV technician. Even if you have fixed the issue on your own, we are asking you to have it inspected by a qualified RV technician.

 

Thanks again for your help!

 

NOTE: We have had an issue with the forums today and I just noticed the Quotes are not working properly. I'll have the team look into it.

[John E Davies]

Matt, so I grounded my inverter at a different location than the bulletin requires. Will my cables have to be completely reworked to meet the exact wording of the bulletin?

 

My TWO big 4AWG cables are grounded at the battery support pillar (which is welded directly to the frame at the bottom). It is as good a ground point as the stud described in the bulletin.

 

 

I just hate to see my good work ripped out if it is OK, because as an ex-A &P mechanic I know my work is of better quality than the typical RV tech. I have seen the kind of work some of them do and it can be very ugly.

 

If my work will have to be redone, I will just refuse to comply with this bulletin. You can send the Oliver Police to my door to arrest me.

 

Please advise.

 

John Davies

 

Spokane WA

[John E Davies]

John, I must have missed your earlier reply about not having a fuse block or disconnect. IMO, I don’t think the ground is worth much without a fuse to blow. 12v is unlikely to shock anyone unless they’re soaking wet, but a short is absolutely a fire hazard on a high amperage unfused circuit. So adding a heavy gauge ground and giving any short a nice clean path straight back to the battery may actually increase the risk of fire, unless you add a fuse to your battery bank. That is, at the moment, your ground wire is also the fuse.

 

If you can verify that you don’t have a fuse, then I suggest you get one of these and a spare fuse, and install it on the positive side of the circuit as close to the batteries as possible. I’d guess on a 2000w inverter that a 300a fuse would be fine, perhaps even 200a, though I don’t know the max draw of your inverter. I have a 400a fuse on mine, with a 3000w inverter, and that was the size fuse that AM Solar recommended to me. While you’re at it, you may as well add a disconnect switch just after the fuse.

 

I think Oliver should amend their TSB to include the installation of a fuse along with the ground cable.

 

My system does have a big inline fuse for the inverter supply cab, it is mounted (and a little hidden) at the back wall of the front electronics compartment (under the rear dinette seat). There is no disconnect, I may add one of those but it is not a priority for me.

 

 

Thanks for the info.

 

John Davies

 

Spokane WA

 

 

[geokeg]

I have hull number 178.  There is no evidence of a chassis ground wire ever being installed on the inverter.  Our unit is nearly 2 years old and the inverter has been operated numerous times to operate the microwave, vaccum cleaner, etc.  I looked at the inverter installation and operation manual supplied with the delivery documentation.  Clearly, step 5 of the basic installation  instructions was omitted.  I wonder how this was omitted on so many units, in any case, not a good showing by Oliver engineering, manufacturing, and quality control.  ( My solar controller also had a wire routing issue, which stressed the controller and made it inoperative, and it had to be sent back to Blue Sky for repair and subsequent wire rerouting to resolve the issue).

 

With all of that said, and clearly an issue, it leaves me with a question.  How does a shock hazard manifest itself and what is the failure mode that makes it happen?  My inverter is installed under the street side mattress in the equipment bay which is covered by a fiberglass panel.  Other than at the mounting points there is nothing in contact with the inverter and I do not understand how I might be exposed to a shock hazard.  The inverter is self protected to shut down if a short circuit or excessive load condition occurs.  What am I missing here?

[Overland]

Other than at the mounting points there is nothing in contact with the inverter and I do not understand how I might be exposed to a shock hazard. The inverter is self protected to shut down if a short circuit or excessive load condition occurs. What am I missing here?

The overload protection and GFI outlet are designed to protect you from power leaving the unit; i.e., the 120v circuit.  They don't, however, protect you from power entering the unit; i.e., the 12v circuit.  That protection is provided via the "ground" cable and the fuse that I was asking John about.

 

By and large, the danger from the 12v circuit isn't electrical shock.  Your skin has enough resistance to prevent much 12v current from passing through your body.  Not that it can't happen - just that it would have to be a special circumstance, like if you had a cut on your finger or if you touched your tongue to the positive terminal.  General rule: don't lick your battery.

 

The danger from 12v, or specifically 12v powered by a large battery, is fire.  Each of your batteries is capable of releasing thousands of amps in a short circuit, which is easily enough to weld with.  Even protected batteries like the ones I have can release hundreds of amps before tripping their protection circuits.

 

So how a fire might occur is if a 12v wire inside the inverter comes loose from vibration, or rubs on the case of the inverter until its insulation is worn off.  If that bare wire touched the case, then a few things could happen:

 

1) If there is no ground whatsoever, it might not do anything, since the current wouldn’t be able to find a path back to the battery.  It would, however, electrify the case of the inverter and if any stray bit of metal should touch it and complete the circuit to the chassis, then it could arc and start a fire.

 

2) If the case of the inverter is bonded to the 120v ground (almost certainly it is), then the 12v current would find its path back to the chassis via that 120v ground wire.  And since the current from the batteries is so high, the relatively small ground wire would quickly heat up and eventually melt, possibly causing a fire in the process.  For good measure, it would also melt off the insulation on its hot and neutral neighbors, creating a 120v short.  It's possible that your battery fuse would blow before any of that happened, but since that fuse is fairly large, it very well might not.

 

3) If you have a heavy gauge "ground" wire attached to the case, the current would find that path back to the chassis, and prefer it over the 120v ground since it has lower resistance.  That cable is (should be) large enough to handle a current that would blow your main battery fuse, cutting the current before it has a chance to heat that cable up and melt it.  If you don't have a fuse then you're back to melting ground wires, which is why I asked John to make sure he had one (my trailer did not, for reasons that hopefully don't apply to any others - though there is no fuse block noted on any of Oliver's wiring diagrams, so maybe best to check).

 

I put "ground" in quotes, since it really just provides any short an alternate path to the chassis.  Even with your jacks directly on the ground, not much current will really go to earth.  The only time your trailer is truly grounded is when you're plugged in and the trailer "ground" is connected to the service ground.

 

I do think it's fair to ask how likely any of this is, and personally I'd put it in the quite-unlikely-but-entirely-possible category.  So it should be fixed, though I think Oliver's email was a bit dramatic.  I don't really understand why they're telling people not to use their inverter, since the potential problems seem unrelated to the inverter's use.  Perhaps I'm the one missing something.  Better advice, imo, would be to disconnect the unit from the battery; or short of that, until you attach a ground, treat your inverter like an extension of the battery, and don't lick it.

[geokeg]

Thank you for that very descriptive and helpful input into what is going on here with this grounding issue.

[MDuncan]

Matt, so I grounded my inverter at a different location than the bulletin requires. Will my cables have to be completely reworked to meet the exact wording of the bulletin? My TWO big 4AWG cables are grounded at the battery support pillar (which is welded directly to the frame at the bottom). It is as good a ground point as the stud described in the bulletin.

 

John,

 

From the looks of where you grounded on the support beam, I'm not sure if that support is welded to the chassis. I haven't personally looked yet on a unit, but I will check.  In any case, we would recommend moving the grounding point to the chassis ground stud.

 

I have the Technical Service Bulletin revised but waiting to hear from everyone here before we post it.

 

Basically there will be three things everyone will need to look for...

Missing inverter chassis ground wire

Oversized ring terminal on chassis ground

Flat washer installed between ring terminal and inverter chassis (needs to be removed)

Again, we will be asking for everyone to get it inspected by a qualified RV technician. We will reimburse the cost of the inspection without approval up to $150. Anything over $150, we are asking that you call the Service Department prior to get approval.

 

Hopefully we will release the revised TSB today or tomorrow. For those that have already requested a Service Kit, we will be mailing those out by the end of the week. We apologize for sending the TSB out then needing to revise. We want to make sure this is done correct and that everyone's travel trailer is setup as safe as possible.

 

 

[mountainoliver]

Matt, the battery box support on my trailer (#208) is not welded to the frame. There is a 1 1/2 x 2 x 8 inch aluminum angle attached to the body. there are two self drill screws holding this angle to the body and the support leg is welded to the angle. The angle is resting on the insulation. Probably the two self drill screws go through the fiberglass and into the frame. The #2 welding cable that I used for the ground is attached to one of the two 1/2 inch rear jack mounts attached directly to the frame. The ground tab you speak of is also attached to the frame with a 1/2 inch bolt but, already has two other grounds attached to the 1/4 inch stud. Due to the potential levels of current possible, I wanted to keep the ground length short and use a fairly large cable. I also feel that the 1/2 inch attachment will carry more current than the 1/4 inch stud. Remember that the minor diameter of a 1/4 x 20 screw is only about 3/16 or so. Not much surface area to carry a large current. Not to mention the metric stud on the inverter. It’s minor diameter is really closer to 1/8 inch or so (only a rough guess as I didn’t look up the minor diameter specs of either 1/4 x 20 or the metric version). My guess is that the small studs will melt long before the #2 ground cable will even get warm. My welder uses #2 cable and I can use (melt) 3/16 rods all day.

[MDuncan]

I've updated the Technical Service Bulletin. They have been emailed and will be mailed by USPS first-class mail today.

 

http://olivertraveltrailers.com/topic/inverter-ground/

[mountainoliver]

Thank you Matt! I appreciate all of you there, you’re all the best!

[BackofBeyond]

They have been emailed and will be mailed by USPS first-class mail today.

Got mine Sat. No issues here.

[Trueaco]

I was planning to travel across Tennessee when I saw this thread.  I scheduled a service appointment with OTT and took a detour to Hohenwald on September 28. As always, I received OUTSTANDING customer service. Turned out, the inverter in my trailer was properly grounded. I was able to ask a few questions to clarify my understanding of the trailer and greatly appreciated the plain spoken and thorough explanations.

 

I continue to enjoy my trailer and am often asked by strangers 'How d'ya like it?' My immediate reply: 'this trailer has exceeded my expectations!'

 

Many thanks to all the folks at Oliver who have designed, produced and support what in my opinion is an exceptional piece of camping equipment!

[DavidS]

First, Kudos to John Davies for discovering this problem.

Second, Kudos to Oliver for a detailed description of the problem and solutions, and their willingness to pay for an RV tech to check out and correct the problem. When John first posted about the problem I went and looked at my ollie. This end of the inverter is not visible from the compartment opening. So I used this telescoping mirror doodad I had in my home toolbox. I could see the cable connected to the terminal, and I felt okay that the unit was grounded.

 

When Matt Duncan posted details about the problem I realized that I did not know whether my grounding cable had a flat washer installed between the ring terminal and the inverter. I could not see well enough back there. So I went back to the trailer and put my cell phone down there and took enough photos that a few were in focus.

 

Hmm. Not clear. I see this metal ring, indicated with the red arrow. Is that a flat washer, or part of the terminal on the inverter chassis? I am going to have to unscrew the nut to answer this question.

 

Oliver offered to pay for an RV tech to look at this, which is really good. But I figured I could handle this, saving Oliver $150 and avoiding the hassle of scheduling the RV tech.

 

Matt Duncan’s instructions had a bunch of good safety guidelines. Pop the circuit breaker, unplug 30 amp power cord, disconnect battery cables from the inverter. I did not do any of those. My Ollie is under cover when in storage, so no solar when in storage, so I have a battery disconnect switch. With the battery disconnected, I figured there are no electrons coming into the inverter, and so I did not follow any of Matt’s procedures for electrical isolation. (If I am wrong about this safety consideration, I know a wiser forum user will speak up!)

 

I used a 10 mm socket wrench to loosen the nut, and then hand loosened the nut further, being careful not to take it all the way off and have nuts and washers spill to the bottom of the compartment. I could not convincingly determine whether my unit contained the problematic washer, either by touch or with my mirror. However, a cell phone photo shows that the metal ring is part of the terminal on the inverter chassis. No washer. Tighten up the nut, and all is good.

 

[topgun2]

David -

 

No wonder your hair has so many curls!  A man that likes to live life on the very edge.  A bit of a kindred spirit in that I would have done the same as you except that I would have still probably flipped the switch on the solar panels just to make absolutely sure that there wasn't anything coming in from that direction - some interior lights (in the storage building) can be enough for solar panels to send a charge on down the line.

 

Thorough check - you did good in my opinion.

 

Bill

[Free2Roam]

 

 

Hmm. Not clear. I see this metal ring, indicated with the red arrow. Is that a flat washer, or part of the terminal on the inverter chassis? I am going to have to unscrew the nut to answer this question....

 

I used a 10 mm socket wrench to loosen the nut, and then hand loosened the nut further, being careful not to take it all the way off and have nuts and washers spill to the bottom of the compartment. I could not convincingly determine whether my unit contained the problematic washer, either by touch or with my mirror. However, a cell phone photo shows that the metal ring is part of the terminal on the inverter chassis. No washer. Tighten up the nut, and all is good.

 

 

David,

 

Thank you so much for this!  We checked ours, Hull#268, and it looks like yours.  I was wondering the exact same thing, whether that was a washer or part of the terminal and was going to contact Matt about it.  I now know that ours is fine.  You have settled my mind.  This is why I love this forum.  Thanks again!

 

Angela