I have the Nations 270 amp alternator and Balmar regulator in our 210. On warm days when cooking using the convection oven, after 30 minutes or so, the Balmar alternator temp sensor limits the alternator output, causing some drain on the batteries until the roast is done.
The Balmar regulator is factory set to limit alternator output at 108 C. I have been reading that 120 C is a generally accepted alternator max operating temp. I am considering reprogramming the Balmar to limit at 120C. Has anyone tried this?
I have the Nations 270 amp alternator and Balmar regulator in our 210. On warm days when cooking using the convection oven, after 30 minutes or so, the Balmar alternator temp sensor limits the alternator output, causing some drain on the batteries until the roast is done.
The Balmar regulator is factory set to limit alternator output at 108 C. I have been reading that 120 C is a generally accepted alternator max operating temp. I am considering reprogramming the Balmar to limit at 120C. Has anyone tried this?
High temp is a known issue.
I would install a scat tube before touching the brains.
OK, looked up the scat vent tubing idea, looks like a good thing to try. Thinking a 12v blower, since this would be while parked and dry camping. Will see about designing something up.
I think the problem is the alternator only gets hot air from the radiator for cooling.
Advanced RV initially installed Nations second alternators in their vans and used ducted forced air directly on the alternator to cool it. They had a failure rate anyway they couldn't live with and what you observed in diminished output was unsatisfactory. I suppose you could reset the alternator temperature limit higher but that makes the odds worse in failure I would think. ARV is now installing more robust Delco alternators and when they swapped out mine they also removed the ducted air. The Delco fits Sprinters but it probably won't fit other vans since it is so big.
__________________ Davydd
2021 Advanced RV 144 custom Sprinter
2015 Advanced RV Extended body Sprinter
2011 Great West Van Legend Sprinter
2005 Pleasure-way Plateau TS Sprinter
I've been talking to Nations, Adam is telling me they have a different bracket now for the Chevy 6.0L that will mount a larger alternator than the 270 I have. I'll post info on that when I get the details.
That is about 250*F, which I think would not trigger the internal regulator in a Nations/DC Power alternator, based on what we saw when we ran one, but it is pretty hot. DC Power says their alternators are not for battery changing, and infer it is because they don't want them at full output for long periods of time. DC power pushes them as for running big audio setups and such or at less than full output for offroad lights and things like that.
The Balmar trips at 220*F or so and goes to 1/2 power which is just enough to let the alternator cool enough, especially with the van sitting still. It is tough to cool down much when the alternator is attached to an engine at 200* in a 150* or more engine compartment. We have found on ours that if we run more than about 60% of rated output, we will get to 220* or a bit hotter. At idle it is tougher for sure as the engine compartment is hotter, as is the radiator that is blowing in hot air.
The cooling hose setups that I have seen put together, for the most part probably don't do much because they bring in air from the front of the van to the alternator. The alternator pulls air in the rear and blows it out at the pulley, so any cooler air would need to go up to the rear to the back of the alternator. Of course the radiator fan is fighting that, and moving air from front to back.
It may be that on the Chevy there is more room for a bigger alternator at the factory alternator location, as the lower mount is very tight, and some years are worse than others, like our 07 that has an extra heater shut of valve and a main wiring harness in the way. The OEM alternator could be moved to the secondary location as it is smaller.
All the more reason for the companies to go to higher voltage systems so the alternators are smaller and run cooler.
I put in this Jabsco 150 CFM blower today (Amazon for about $130). Did some testing running a 1600 watt grill (about 150 amp draw). The alternator reached about 76 C (168 F), with blower on the alternator temp reduced to 62 C (144 F) - outside temp was about 32 F. Due to the cooler temp today, I didn't reach high temp cutback, will test more next spring on a warmer day.
On page 13 they show a cooling setup for their alternators.
As I mentioned earlier, the air comes into the alternator in the rear, which this setup shows well. Just dumping air around the alternator, especially on the pulley end, just gets blown around and not into the alternator.
Perhaps the Balmar piece could be made to work with the Nations alternator. I you took the air from a cool area, in the front of the van or out the side, you might see some dramatic improvements.
The alternator likely has double fans in it, so you probably wouldn't even need a booster fan, just a hose to the cool air.
Right, that applies to an alternator with external fan on the front drawing air from the rear. The Nations 270 alternator has internal fans similar to this diagram (courtesy Delco 28SI brochure). It seems to me that air directed to the front would be beneficial for this design.
You are likely correct. The other dual fans I have seen merely had two fans boosting the flow, 1 in the back and 1 out the front. This may also help explain why the Nations seem to run substantially hotter on the laminations in the middle of the alternator than others I have seen, as all the hot air is exiting there. There have been some ongoing discussions about where the proper place is to check the temp, as the laminations tend to run even hotter than the plus post that is attached to the diodes, on many units.
I do wonder how they prevent hot air looping in that setup though, especially in an engine compartment in a vehicle that is going to put all the front hot exhaust right into the rear inlet. Perhaps a sealed, fed, rear inlet would help that part of it.
Yes, at the end of the day, my goal is to be able to cook on a warm day without the Balmar alternator temp regulator going into cutback mode. It will be interesting to test, but I need a warm day, next spring here in MN.
Alternator temperature
Linear Mode
