Xantrex 3 stage Voltage regulator....will it work with MCI generator?

ChuckMC8 · November 06, 2006, 11:42:18 AM

My delco voltage regulator has stopped working. It is apparently an upgraded/modern circuit board design....I removed it and took it to an electrical savvy friend who is checking to see if it can be repaired. I didnt ley the smoke out of it...it just quit functioning.
Soooo.......I found a new replacement for $108.00. But someone had mentioned using one of the Xantrex 24volt 3 stage regulators. I havent seen this done on a bus, and I didnt want to call Pakistan or India to ask the Xantrex guy "Bill" if it would work.
Heres what it says on the Xantrex site...

Xantrex Alternator Regulator
With the Xantrex Alternator Regulator, you can turn your high output engine alternator into a powerful three-stage battery charger.

Heres the link to the Xantrex web site: http://www.xantrex.com/web/id/107/p/420/pt/7/product.asp

Apparently, this retails for $350 and is available for $250 or so without much shopping. I'd have to find it considerably less for me to try....not being cheap, just dont have the $$$ now.

I charge my 2 gp 31 starting batteries and have a relay connection to my house batteries (8 golf cart batts) with the bus alternator.
(This bus alternator also charges the 8 golf cart batteries)

thoughts?

rayshound · November 06, 2006, 12:23:15 PM

Hi Chuck,
I wish I had the info you needed but I don't. A few busnuts have posted in the past with good luck using this VR. I am counting on doing this myself as I will rebuild my belt driven 50Dn I hope to use the new regulator and I will use it to drive my inverter. I have not got to that stage yet. I will mount it on my repower S-60. I'll be watching this string to learn from also. Ray

DrivingMissLazy · November 06, 2006, 12:32:14 PM

It would seem to me that a three stage regulator would only be needed if you are re-charging house batteries with it.
Richard

Jeremy · November 06, 2006, 01:53:13 PM

Bear in mind that the purpose of a multi-stage regulator is to provide a very high charge-rate (ie. high current) to a discharged house battery, then use 'intelligence' to reduce the charge rate to prevent damage as the battery becomes full. If the cable from your OEM regulator is connected directly to the start batteries then you could probably replace it without any problems, but if there is any chance that those high currents could get elsewhere into the bus wiring without the battery acting as a 'sink' you will probably do some damage.

The multi-stage regulators are neat pieces of kit which can (for instance) greatly reduce the need to run the generator to charge the house batteries. So, if you can get one, do so, but realistically it's going to be in addition to the OEM regulator, not instead.

Jeremy

NJT5047 · November 06, 2006, 06:31:35 PM

Parts for the Delco reg can be bought inexpensively. If this system has been working satisfactorily, may be reasonable to go with repairing the Delco. I'd worry that the $250 buck Xantrex would take a crap.
One thing is for sure, if the Delco senses a charge of any kind on the batts, the "no gen" light comes on.
I changed my fuel filters today and cranked the bus...got a no-gen light...that's new....then remembered that the inverter was on and charging the batts....probably a good way to let the smoke of out an expensive charger? Turned it off and..problem fixed.
Used Delco regulators are pretty cheap too.
Post the outcome if you use the Xantrex....be interesting to see how much better it does over the OEM alternator system.
Best, JR

DrivingMissLazy · November 06, 2006, 06:36:26 PM

Quote from: Jeremy on November 06, 2006, 01:53:13 PM
So, if you can get one, do so, but realistically it's going to be in addition to the OEM regulator, not instead.
Jeremy

I do not think so. The three stage regulator will replace the exixting regulator.
Richard

Jeremy · November 07, 2006, 02:00:52 AM

Quote from: DrivingMissLazy on November 06, 2006, 06:36:26 PM

I do not think so. The three stage regulator will replace the exixting regulator.
Richard

I may be wrong, but I had always understood that the Xantrex-type regulators were intended to be wired to the alternator output in parallel with the OEM regulator, so the OEM regulator continues to charge the start batteries (as it was indended to), and the Xantrex charges the house batteries (as it is intended to). This also gives a level of redundancy, which is a good thing.

I don't yet have a multi-stage regulator (missed one on Ebay recently at £35 - bugger), so maybe someone who has one installed can confirm either way

Jeremy

edroelle · November 07, 2006, 06:35:12 AM

Chuck,

I have experienced this. I had installed it on my MCI 8.

Theoretically, it will work. The Xantrex regulator is suppose to be able to handle 10 amps as I remember. My circuit was only 6 amps. So, it should work. However, my Xantrex regulator failed after only about 600 miles. The transistors in the unit were melted. Xantrex replaced the unit under warranty.

Something is going on that I did not understand. There may have been a transient that exceeded the 10 amps. I don't know if it worth the gamble for the benefit you might gain.

By the way, I lunched a couple of inexpensive Xantrex inverters. After digging into it with the Xantrex technician, we were able to understand why it occurred. My point is that I think Xantrex designs are weak when in comes to failure modes. Don't stress them to their limits, or use them where they may not be designed to use. (Reference the grounding circuits in some of their SW4024s.)

Ed Roelle
Flint, MI
Flint, MI

DrivingMissLazy · November 07, 2006, 08:19:39 AM

I do not see how you could have two regulators controlling the same alternator. There is only one field winding and one DC output.
i suspect the Xantrex takes the existing DC voltage from the alternator and then regulates it. Not regulating the alternator output directly.
Unfortunately not much information on the Xantrex regulator in their information, but I can assume that 10 amps is not good for much.
Richard

ChuckMC8 · November 07, 2006, 01:00:48 PM

Richard, I think that what Ed is refeering to with the 10 amps is the feild wire amps, not the charging amps of the generator-IMBW

DrivingMissLazy · November 07, 2006, 01:46:27 PM

The Xantrax literature, for what it is worth, indicates that it is capable of ten amps output. I have never seen an alternator require this much current for excitation. Woulld really like to know what this device is, but I do not think it is a regulator for an alternator.
Richard

pvcces · November 08, 2006, 10:35:28 PM

Guys, the information you are seeing is normal with those alternators and those regulators. The 12 volt version of the alternator used on the 4106 draws 8 amps for a 220 amp maximum output, so the 6 amp current should be about right for the 24 volt unit.

The 10 amp rating of the regulator matches what we have, as well. We did not install it on the coach because we bought it for our boat. It's alternator doesn't draw quite that much.

While I was testing our regulator, I accidently ran way more current through it than it was rated for and popped the final. I got curious about it, so I took it apart and replaced the final with off-the-shelf parts. The repair was very easy and it worked just fine, afterwards.

George Lowry used one of these units in his 4106 from the conversion until he sold his coach. IIRC, he said he never had any trouble with his.

The biggest problems with the stock regulator are that it's very dumb and it doesn't turn on and off quickly, so pulsing of lights is common. We have no problem running start and house batteries tied together as long as they are automatically separated when the charging souce is turned off. We do this with a pathmaker.

The main reason that a three stage regulator is needed is to speed up the recharge without damaging the batteries.

I hope this helps.

Tom Caffrey
Suncatcher
Ketchikan, Alaska