Inverter / Bulkhead - Mounting advice wanted...

[technomadia]

Greetings all,

The project for the past two weeks has been designing our electrical system upgrades, and plotting our snazzy new lithium house battery bank.  I'll share details of all the electrical goodness soon.

But right now - I'm looking for advice on how to best mount the new inverter / charger to a bay bulkhead in our 4106.

The bay we are using for the new electrical chamber is the former ventilation bay, the first hatch on the curb side behind the front tire.  We'll be wanting to mount the 40lb inverter (a Victron MultiPlus 3000) on the rearward wall of the bay. 

Because the diesel tank is behind the wall, it would be hard to reach to use bolts.  So..  Any advice on what is considered best practice?

Rivets, metal screws, riv-nuts, a mounting board...  Or maybe velcro, for easy maintenance?  ;-)

How thick are the bulkhead walls in a 4106?  Any tips on mounting a heavy inverter from those who've done something similar would be much appreciated.

Thanks!

   - Chris

PS: One nice side effect of using this bay is the existing bus original #00 wire run that heads back to the starter batteries, and which used to power the ventilation blowers.  We'll be tapping into that to get charge current from the alternator for the house bank.

[Fred Mc]

The door on the fuel tank will open up. It is bolted at the bottom but is hinged At the top. The bulkhead you want to use is where I mounted my "converter". Did it before inverters were common.

Regards

Fred  GMPD4106

[John316]

How about really long self tapping screws, right into the bulkhead? Just kidding BTDT (some of the guys on here know, but I put two self tapping screws into the bottom of our fuel tank, when I had 150 gallons of diesel in it...not fun!).

Seriously, though. The reason that I posted, was to share an old reminder. Most inverters, that I know of, need to be kept 100% dry. We mounted ours, so it will vent into another bay, and not directly outside. We could not take a chance of any kind of water getting into them. (When we were caught in the flash flood, the first thing we did was turn the inverters off. We were SO grateful that the water was still 1in below them. It pays to have good seals on your doors!).

That said, I have zero knowledge about your style/model of bus. JMHO

John

[bevans6]

1/4" or 5/16" rivnuts in steel would work.  I can tell you how to install them without a special tool.

Brian

[Melbo]

How much room is between the tank and the bulkhead??

If there is not much how about 1 1/2 inch steel strap that goes from the top of he bay to the floor of the bay about an inch from the wall.

Bolted at the top and bottom would be easy to put nuts behind or even tap for bolts to thread into.

Also would allow for ventilation behind the unit and if necessary to avoid vibration you could put rubber bumpers between the wall and the straps if necessary.

HTH

YMMV

Melbo

[buswarrior]

Mounted mine (a larger Trace 4024) to a 3/4 plywood board sized to sit on the floor of the bay and then just need stabilizing at the top. No hanging weight that way.

if putting fasteners through into the fuel tank area, think really hard about what those fasteners might do in wrestling the tank out and back in, when the time comes.

It is a fairly dynamic event!

happy coaching!
buswarrior

[technomadia]

1/4" or 5/16" rivnuts in steel would work.  I can tell you how to install them without a special tool.

I'd love to know how to do this.  Sounds very useful.

Thanks!

  - Chris

[technomadia]

Mounted mine (a larger Trace 4024) to a 3/4 plywood board sized to sit on the floor of the bay and then just need stabilizing at the top. No hanging weight that way.

I think I've settled on a plywood mounting board with angle brackets at the bottom that I can screw it to the floor, and then I can easily secure it from forward/back motion at the top with lighter weight hardware.

I'm also contemplating reversing the layout to put the inverter on the front wall instead of the back.  This way breaking forces will be very well braced, and I can also more easily get behind the front bulkhead to solidly secure things.

One major advantage of going with a plywood mounting board is that it will make securing all the smaller bits (like current monitoring shunts and the low voltage cutoff relay) a lot easier.  And - I will be able to take the whole board out intact for upgrades and maintenance.

Thanks everyone for the ideas!

  - Chris

[technomadia]

The door on the fuel tank will open up. It is bolted at the bottom but is hinged At the top.

Thanks a bunch for this tip, Fred!  We opened up the fuel bay today and got our first look at the fuel tank. 

We have been curious to confirm our fuel tank size, so we took some measurements - 20" x 30" x 48".  However, that only calculates out to 125 gallons, when we were expecting 140 at a minimum (if the tank is still stock).

Curious if anyone knows the dimensions of the 4106 tank, and if perhaps we just mis-measured (as the depth is a bit tricky to get)?  At our last fuel fill up, it cut off quite a bit earlier than we were expecting based on our conservative estimates for fuel economy.  So either our tank is in fact smaller than we thought, the bus is getting better than anticipated fuel economy or we forget to record a fill-up.

Thanks,
- Cherie

[bevans6]

http://www.fjr1300.info/howto/rivnut-tool.html is a page with instructions  on how to make a riv-nut tool.  It's very easy, I have installed a lot of steel riv-nuts this way.  You basically use a bolt and a nut to draw the riv-nut tight.  The three turns you need to be well aware of, in actual fact that may vary  slightly depending on the thickness of the material and the pitch of the threads your nut has, so you can do a test piece with material the same thickness as your bulkhead.  I personally use fine thread steel riv-nuts in steel and coarse thread aluminium riv-nuts in aluminium.

Brian