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Topic: Inverter Replacement (Read 1880 times) previous topic - next topic

Inverter Replacement

I planned to replace my Xantrex Freedom 2500 this spring with a Magnum MS2812 until I took some measurements.  My unit is ceiling mounted in a rack screwed in place.  The Magnum is over a 1/2" wider, meaning the rack would have to be modified, missing the bracing it is screwed to.  What have others done?  My inverter is mounted in the large joey bed bay.  There doesn't seem to be another convenient place to mount it.  Alton at FT recommends replacement with The Xantrex Freedom 458, which is a modified sine wave unit, presumably because it fits easily in the existing rack.

Re: Inverter Replacement

Reply #1 –
1.  Modify the rack (widen it) to fit the larger inverter, but retain the same mounting bolt locations.

2.  Mount the inverter to the wall of bay.  This is what AM Solar did with our MS2812.  They fabricated a aluminum plate that mounted to the metal ribs in the bay wall with recessed bolts.  Then bolted the inverter to the metal plate.  Has been perfectly secure and happy in that position.

Re: Inverter Replacement

Reply #2 –
Or you could retain the original mounting bracket on one side only, and fabricate a new mount for the other side.

Re: Inverter Replacement

Reply #3 –
On our 99 I mounted the Magnum as Chuck suggested.
jor

Re: Inverter Replacement

Reply #4 –
If you can find a vertical wall it makes connections easier.  The Magnum is deeper and will stuck out into the space where the joey bed is.  When I put my Victron in there I had to do some basement space changes.

I used a 1/2" baltic birch plywood panel with holes to allign with framing in the basement wall for mounting the panel and holes through it with T nuts on the back side to bolt the inverter to the panel.  A bit oversized and it gives you room to attach cables firmly. A thin aluminum sheet (20 ga) attached to the plywood panel acts as a heat sink and fire proofing.  Of course everything else around it is flamable so pay attention to clearance specs.

When you move your inverter your cable lengths may be longer.  Magnum suggests 4/0 cables for under five feet and 2 4/0 cables for both + and - sides if they are longer than 5 ft.  Power goes both ways in these cables for charging and inverting.  Don't skimp here.  You are likely to have only 3/0 cables now from the batteries to the common posts and to the old inverter.  You might want to upgrade the cables to the batteries as well.

An alternative would be a Victron 3000VA Multiplus.  It costs less, weighs less, higher continuous output, higher peak output.  Compare specs. 

Re: Inverter Replacement

Reply #5 –
I installed the 3000W hybrid version (same form factor) of the Magnum in a vertical orientation. This was a bit more involved because of the necessity to use a hood when oriented vertically and because I had to relocate the DC breaker panel to the roof in the old inverter location. I also used some sheet aluminum behind it because the instructions say to mount it on a non flammable surface. I was able to use the steel framing for three of the mounting bolt locations. For the fourth, I used a backing plate on the other side of the compartment wall. This location kept the total cable length between the batteries and the inverter to less than 6', even with the battery slides, and the vertical orientation allowed the installation of the the Magnum Mini-Panel right next to it. The Mini-Panel has a 250AMP inverter disconnect/breaker and an A/C bypass to allow easy removal and replacement of the inverter. The bypass allows the inverter circuits to be utilized while on shore or generator power while the inverter is removed. Just another way to approach inverter replacement. I got tired of the old hanging inverter collecting scalp fragments and limiting what I could put in the joey bed.
Don

Re: Inverter Replacement

Reply #6 –
I can't offer any additional worthwhile suggestions for mounting but I strongly suggest that you go with a pure sine wave inverter rather than a modified sine wave and I can tell you that we have been extremely pleased with our Magnum.

Re: Inverter Replacement

Reply #7 –
If you are changing cabling the few dollars extra to get marine grade pvc coated fire retardant UL 1427? Tinned would seem to be a good idea.  Every boat has it as far as I know.

Something about AWG being even larger than other styles.  15/16th inch diameter 4/0 cabling? 

Make sure no gas emitting batteries are where any non sealed inverter is to be mounted.

Big difference going from the freedom 25 to the ms 2812. 

My freedom had worn internal contractors that reduced the chargers output power by 30% or so.  They get pitted from use.

Microwave runs quieter with full wave power. 

I rebuilt the alternator at the same time. One out of six diodes was bad.  Plus new bearings and a new idler pulley.

And a  combiner.  Good for another 20 years.

Re: Inverter Replacement

Reply #8 –
Quote
Something about AWG being even larger than other styles.  15/16th inch diameter 4/0 cabling?

Yea, the Magnum calls for 0000 cable. I don't think most upgrade from the factory setup though.
joir

Re: Inverter Replacement

Reply #9 –
4/0 cables are not all the same.  Both Magnum and Victron specify cross section area of the actual wires.  For 6 ft for example, 107.2 sq mm for Magnum and 100 sq mm for Victron.  If you ae buying cable more strands of higher ga number (finer) wire will make it more flexible.  Battery cable is often several bundles for fine wire strands twisted around each other.  PVC jacket is fine but is less flexible than an EPDM cover.  When hooking these inverters up flexibility is important.

My Victron was easy to hook up with 2 each 4/0  plus and minus very flexible EPDM covered 105°C welding cable with more than 2000 very fine wires inside.

Re: Inverter Replacement

Reply #10 –
Quote from: Roger & Susan in Home2 –
If you are buying cable more strands of higher ga wire will make it more flexible. 

To explain for those not familiar with wiring:

Higher ga= Higher gauge= Finer gauge= Wire with smaller cross section/diameter.

Yup, same overall cable dimension made up of more strands of finer wire has less resistance than same dimension wire made up of fewer, larger strands.

Guess which is more expensive??

Re: Inverter Replacement

Reply #11 –
Run a heavy load on the inverter for a while.  Heat gun the battery wiring.  If it's warmed up you are losing power heating the cables.  Bigger wires.  Less power draw. Duh

Re: Inverter Replacement

Reply #12 –
Do not consider any modified sine wave inverters. Not for any reason.

Don't cut the Freedom 2500 battery cables. Disconnect from battery & ground, remove 2500 & open up the case. Root around, destroying anything in the way to UNBOLT the battery cable from inside the 2500. Then re-use battery cables.

Good luck.

Re: Inverter Replacement

Reply #13 –
Magnum I think was different on the ends

Re: Inverter Replacement

Reply #14 –
x2 on not using modified or square sine use only pure sine wave.  Most things would be ok but with the price of electronics there is no way I would not use pure sine wave inverter
Just my 2c worth
Chris

Re: Inverter Replacement

Reply #15 –
Magnum has external battery connection posts where cables are attached with a nut.  Original undamaged 2500 cables have the necessary lug ends to be used on these threaded posts.

Re: Inverter Replacement

Reply #16 –
Don,

Where did you mount the air compressor that is bolted to the inverter rack?  How much rewiring was required to move the DC breaker panel?

Re: Inverter Replacement

Reply #17 –
Brett,
I mounted the (upgraded) air compressor on the compartment wall on the passenger side of the nook. The air lines were long enough. The breaker panel move required very little rewiring as I recall. I just mapped the framing of the compartment roof in the area where the old inverter/compressor frame was and attached the breaker panel to the ceiling. I think I might have made a new grounding cable, but all of the smaller DC wires that connect the breakers stayed in bundles as I rotated the panel. As for the HWH compressor which had shared the inverter mounting frame, I fabricated a mounting plate from quarter inch aluminum for the Arb twin compressor and the water separator assy. and used the HWH pump relay on the DC breaker panel to feed the 40 amp Arp compressor relay which got its power from a new fuse protected house battery bus feed.
Don

Re: Inverter Replacement

Reply #18 –
Hey Don, now that you've had it a while, what do you think of the ARB pump setup?  How much faster does it fill the HWH tank than the original pump?  How is the noise compared to the original pump?  I see that the specs say it will pull almost 70A DC at max pressure where the original only pulled about 28A.  What are your thoughts overall?

Re: Inverter Replacement

Reply #19 –
I changed out my Heart Freedom with a Magnum 2812 as well. My inverter is mounted along with the air compressor and the area was a bit shy of space for the Magnum.
I took the rack off and had it modified with a bit of welding and re installed it with the air compressor.
If you want I can PM some photos to you.
Peter