[Tim]

Parts for the 2500 are getting few and far between, so you may have to look at replacements such as Magnum. You should talk to the experts at Inverter Services, a PC advertiser and get their take on your problem.

Inverter Service

[Archived]

First the disclaimer: I think (and the inverter experts apparently agree with me) it is foolish to run AC units from inverters when we all drag around perfectly good generators that will supply power to everything on the bus and permit the use of the entire electrical system while driving. The generator is likely to use about 1/2 gallon per hour so it is not like there is a penalty for its use, considering the bus alternator and inverters are going o be only lightly loaded saving their life.

You can put in a larger inverter if you wish, but the cables from the batteries and the electrical wire from the inverters to the electrical panels may have to be proportionately increased in size to handle the extra battery current draw and electrical output. In addition if the converter set up the electrical panel in your coach so it limited which AC unit(s) could receive power from inverters you may also have to modify the panel because you might be adding an ability you presently do not have.

If a 2500 watt inverter i now used to handle the load of one AC unit, you are asking it to handle an intitial starting current of about 4200 watts before the AC settles down to its running load of about 1600 watts. So the bottom line is adding the ability to handle two AC units means an inverter with a 4000 watt rating is going to be pushed harder, but worse, if both ACs cycle on at the same time that may prove inadequate. I do not know what wire size for the 120 output was used on the 2500, but I owuld guess it was a #10. So stepping up the output to a 4000 watt inverter at the least might require going to #8 wiring. Similarly the cable from the batteries may also have to be increased.

Then consider your coach alternator which is likely to be a 270 amp 50DN with a 12 volt rating.

One AC unit when runing is putting a 12 volt load of about 130 amps on the aterrnator. That does not consider the other loads you typically have in the house when going down the road such as the refrigerator. The bottom line is with one AC running the alternator has ample additional capacity to match the current draw. Add in a second AC unit and now the alternator is running at its max output (and getting hot) and may not be charging the batteries, or even keeping up so after driving with 2 AC units running from 12 volt inverters and a 12 volt alternator your house batteries may need a charge.

Run the generator to keep more than one AC working while you drive.

[Tim]

His CC is not setup to run an AC, so I think the question is whether to try to repair the 2500 or replace it. Like in my first post, with lack of certain parts, I would lean to a couple new Magnums and be done with it. I’m not suggesting it can’t be fixed, but even if repaired, it’s only a matter of time, I’ve been there with the 2500’s.

[Archived]

Thank you both. Tom is correct, I do not have any a/c units running off of the inverters. The question regarding size was one of durability and it sounds from what Jon says that a larger unit will not need to work as hard. Hopefully, Magnum has a direct replacement or at least adapters for the remote panels.

I was was not a proponent of running the generator very often but considering how quiet and smooth the generator runs I am becoming a convert. I was more in the camp of solar + Li-ion so this new way of thinking will save money and keep the systems simpler and probably more reliable.

[Andrew]

We had one of our Freedoms give up shortly after we bought our coach. Decided, as Tom suggested to you, to upgrade both to Magnum 2812’s. Was a direct, drop in replacement for both the inverters and the remotes. I would suggest if you do upgrade to do both at the same time…the Freedoms are modified sine wave; the new Magnums are pure sine wave. Most, if not all, of our modern appliances run much better on the pure sine wave. I’m not an EE, so can’t talk to mixing a Freedom with a Magnum…But I would think it would not be a wise move.

[Archived]

Thanks Mike, I will probably go with the dual Magnums as has been suggested. BTW, I am an EE but my background is with medium to high voltage equipment typically 5 kV – 138 kV and and includes UPS systems (we manufacture our own inverters) as large as 20 MW at medium voltage (13.8 kV – 34.5 kV) we also have the largest installed base of battery storage systems than anyone else associated with renewable energy installations. I have also given continuing education courses to electrical inspectors regarding medium voltage applications. So I feel comfortable in telling you that as an EE I don’t know squat when it comes to these systems so that puts me in the same class as most.

The EE probably gives me an advantage in being able to understand this stuff but I have learned that the devil is in the details and I certainly lack the knowledge base when it comes to these systems as they are a specialty.

Your sharing of your experience here is very much appreciated – thanks.

[Archived]

Andy, I know < squat, but swapped in a pair of magnum 2824's couple months ago. Ejecting the oem xantrex ones. Mine were so old I had to splice in the remotes and telephone jacks to the oem wires. But did not have to run any bigger wire, as these 2800 watters are not much different. Old ones 87 pounds each, new ones 47. You'll do fine.

[Andy]

We replaced one Heart interface with a Magnum MS4024 and ran it with the other Heart for 3 years, almost to the day. The other one failed and we replaced it with the same Magnum. Didn’t notice any abnormalities in the mean time.

http://prevostcommunity.com/forum/threaddetails.asp?Category=Electrical&ThreadID=5592

[Archived]

Thanks guys, your input is much appreciated. Of the two inverters, one is the original (1999) and the other was replaced in 2008. Also, one of them had the fan replaced at one time. I did not take the time to figure out which one smoked and which one had the fan replaced or it may have been the same unit but the unit that was smoked had the fan working. The nice lady from the Country Coach system was yelling “DANGER DANGER polarity is reversed.” I checked the outlet and it was fine but I was surprised that the inverters did not shutdown or send an error to indicate that one had failed. Apparently, the the nice lady yelling was enough to scare one of the inverters into releasing the factory installed smoke so I shut them both down and checked often to make sure that the smoke was dissipating and not continuing to smoke.

I decided to just replace both with the Magnum MS2812 and remote panel. Holland Motorhomes will be doing the work and that is where Panterra Luxury Coaches has much of their work done. I did have them buy through Inverter Services as suggested by Tom since they support PC.

Again, thanks to all.

[Steve]

Well the new Magnums have been installed by Holland Motorhomes in MI but there still seems to be an issue with the coach sensing reverse polarity when connected to shore power. We had hoped that this reverse polarity issue was inside the inverte rthat let the smoke out but apparently it is not but probably contributed to frying the inverter (although I cannot be sure). Since we were able to measure 120 vac between the ground and neutral in the bedroom service panel I suspect that there is a short to neutral becasue if it was to ground a breaker should have tripped (hopefuly).

Holland is trouble shooting as I type so I was wondreing if anyone has run into this issue with their coach.