Re: Engine Alternator use: Reply #50 – September 01, 2015, 05:17:20 am I think it would be easier, cheaper, and more effective to fix the dash A/C. Parts aren't that bad and the only special tool would be a vacuum pump. Worth buying one just to save the cost and be able to do yourself. Quote Selected 2 Likes
Re: Engine Alternator use: Reply #51 – September 01, 2015, 07:58:28 am Quote from: Tim Fiedler – September 01, 2015, 12:56:40 amFor Fun, I looked up a Dometic Brisk Air RV AC specifications. For a 15,000 BTU model - the RLA (Rated or Run Load amps range from 12 - 12.9 Amps - the LRA (Locked Rotor Amps) ranged from 71 - 77 amps. So to run this air conditioner off an investor, the investor would need to tolerate a surge in excess of 70 amps for 1/3+ second. Check your inverter and see what is it's surge capacity.The application of a Hyper Engineering soft starter (about $250.) would reduce the LRA to below 28 amps for this unit.Please post the RLA and LRA from your roof air units when you get a chance.Tim:I have the Coleman 13,500 BTU roof airs. According to the spec I found on-line the LRA is 54 amps. The running watts is 1560 - so RLA is say 13 amps.Do you have a link where I can order the Hyper Engineering unit. Would like to get it by this weekend, planning to do some serious coach work... Quote Selected
Re: Engine Alternator use: Reply #52 – September 01, 2015, 08:36:02 am If I were planning on using my engine alternator to operate my roof air conditioner while driving, then I would seriously consider using a Delco Remy 40si instead of a 28si.http://www.delcoremy.com/Documents/Brochures/28SI-Brochure.aspxhttp://www.delcoremy.com/Documents/Brochures/40SI-Brochure.aspxThe 40si is more expensive, but it is a much heavier-duty unit and is much better suited to long-term, high-output applications. Devices such as alternators provide much more reliable service when operated for long periods well under their rated output. Quote Selected
Re: Engine Alternator use: Reply #53 – September 01, 2015, 09:40:58 am David:Yes, I have looked at the 40SI, awesome alternator. May want to get one, they occasionally show up on eBay. Would need to beef up the alternator wiring to the isolator and batteries. Has anyone put one of these bad boys on their coach? Quote Selected
Re: Engine Alternator use: Reply #54 – September 01, 2015, 09:58:19 am Www.gen-pro.biz Quote Selected
Re: Engine Alternator use: Reply #55 – September 01, 2015, 10:03:51 am Quote from: prfleming – September 01, 2015, 09:40:58 amYes, I have looked at the 40SI, awesome alternator. May want to get one, they occasionally show up on eBay. Would need to beef up the alternator wiring to the isolator and batteries. I am guessing you either have or will upgrade the wiring from the alternator to the batteries and possibly the inverter if you plan to run the roof air with the alternator output. I'm not sure what gauge wiring currently exists in your coach, but I suspect an upgrade would be at least desirable and perhaps required. Quote Selected
Re: Engine Alternator use: Reply #56 – September 01, 2015, 03:02:10 pm This thread has morphed from "alternator" to "run A/C from inverter" at reply 42.I find it very interesting, so would it be possible for a moderator to start a new thread at circa reply 42? Quote Selected 1 Likes
Re: Engine Alternator use: Reply #57 – September 01, 2015, 03:47:53 pm There is also the mention of using an engine driven A/C generator, which is perhaps basically the same thing, but there are apparently products aimed at the marine market that may be a different option than a big battery bank and large inverter that is used in the normal coach loads. It would be interesting to open this subject up to all the methods that don't involve firing up the generator run the roof air while driving.DonQuote from: P. Wyatt Sabourin – September 01, 2015, 03:02:10 pmThis thread has morphed from "alternator" to "run A/C from inverter" at reply 42.I find it very interesting, so would it be possible for a moderator to start a new thread at circa reply 42? Quote Selected 1 Likes
Re: Engine Alternator use: Reply #58 – September 01, 2015, 03:54:48 pm Prevosts all have options to run AC off the main engine. Some have a whole setup called over the road air and others just have a large compressor and others a big alternator. Quote Selected
Re: Engine Alternator use: Reply #59 – September 01, 2015, 04:13:10 pm Just for useless info my MCI alternator was 275 amp @ 28VDC, compressor was 9 ton belt driven, condenser fan required 95 amps, evaporator /heater fan 55 amps. Of course it had to keep 48 folks comfy. Point is: You can make anything you can dream up. Quote Selected 2 Likes
Re: Engine Alternator use: Reply #60 – September 01, 2015, 05:51:34 pm Here's another idea I had, and may do one day as I likely will come across a spare dash A/C Heater module. I'd "tee" into the high and low refrigerant lines and add a second evaporator and air handler mid coach. Also add the heater, because in u270 no way to throw engine heat.If needed, up the size of the compressor ("cheap" a couple hundred bucks) and worst case, increase size of condensor. Think front/rear A/C like on a suburban or van. The dash AC is rated 17,000 btu/hr. I doubt it puts this out due to poor airflow (very cold air and low side pressure are always very low). So there is possibly more "cold" in the lines without a bigger compressor/condenser.Not a horrible thing to try, just need to tee into the lines--beg, borrow, buy the crimp tool for A/C lines. Quote Selected 1 Likes
Re: Engine Alternator use: Reply #61 – September 01, 2015, 07:19:41 pm Quote from: Don & Tys (AKA acousticart) – August 31, 2015, 11:32:51 pmInteresting info Tim! Sounds like I may be in a good situation to implement this option on our coach...The Sterling alternator to battery charger would be a plus as well, though we would probably still need to go bigger on the alternator (only 160amps now).DonIMO, alternator to charger add-on is for "dumb" alternators, not needed with the remote sense technology of the Delco 28SI and 40SI. Quote Selected
Re: Engine Alternator use: Reply #62 – September 01, 2015, 11:17:37 pm Someone do the math (Please) to see how many hours a generator would run for the expense of one of these modified systems.. pc Quote Selected
Re: Engine Alternator use: Reply #63 – September 02, 2015, 01:44:05 am Peter,I think that the point of the Sterling alternator to battery charger is really to have customizable multistage charging capabilities and to provide a better charging rate for the house batteries once the chassis battery gets what it needs. It also provides isolation between the house bank and chassis batteries, removing the need for the diode based isolator (or other type). You can also (for a price) have a remote control and display for it. Alt least that is my take on it... I haven't done mush research on these more advanced alternators, but I don't see why they wouldn't work well together even if it isn't as much of an improvement as with the "dumb" alternators.DonQuote from: prfleming – September 01, 2015, 07:19:41 pmIMO, alternator to charger add-on is for "dumb" alternators, not needed with the remote sense technology of the Delco 28SI and 40SI. Quote Selected
Re: Engine Alternator use: Reply #64 – September 02, 2015, 01:55:48 am For me at least, it isn't about saving money on diesel fuel to run the generator, but about reducing the vibration and noise while going down the road. Without running the generator (and front roof air!), our coach is nice and quiet and smooth going down the road. Better than most cars... with the generator running, not horrible, but very noticeably less peaceful. Running the rear roof air and the dash air increases the comfort level without the commotion, or would if we didn't have to run the generator to make that happen. Not super high on the priority list as we have found the dash A/C to be adequate for the most part. But since we have a good sized house bank (4 8D AGM's) and reasonable inverter (3000W), it is kind of an attractive idea to add a couple of bits to the kit to make it happen. Just my take on it... DonQuote from: pocketchange – September 01, 2015, 11:17:37 pmSomeone do the math (Please) to see how many hours a generator would run for the expense of one of these modified systems.. pc Quote Selected
Re: Engine Alternator use: Reply #65 – September 02, 2015, 03:46:35 am Don,Interesting, my 10 kW 4 cylinder genset can only be detected by the light on dash control when running down the road. Guess the 8 kW, 3 cylinder Isuzu does not share the same trait.My generator fuel burn is 10 gal per 24 hrs max, considering the comfy, the cost is forgotten.I do not need to run The roof a/c, the dash a/c is plenty while on the road, My biggest mistake is when I get up, the genset is started for the S,S,Shave routine, breakfast & topping off the 4 8D Gel's, then getting on the road forgetting the genset running for hours or until I notice the light on. Never hear nor feel it, so wonder what the difference could be ? Mounts, exhaust bumping ?I have zero need to re engineer a very fine functioning system.Thanks Quote Selected
Re: Engine Alternator use: Reply #66 – September 02, 2015, 04:35:14 am Quote from: Don & Tys (AKA acousticart) – September 02, 2015, 01:55:48 amFor me at least, it isn't about saving money on diesel fuel to run the generator, but about reducing the vibration and noise while going down the road. I agree with Don...I think with the older coaches (at least mine with the Onan 7.5 kw) the generator noise is noticeable inside the coach, and I prefer not to run it, the cost of diesel really doesn't weigh into it.Quote from: Dave M – September 02, 2015, 03:46:35 amI have zero need to re engineer a very fine functioning system.For me, half the fun of owning a coach is tinkering, trying new things, and by doing all the work myself I'm not spending a lot of money. Also, my wife says it keeps me home at night... Quote Selected
Re: Engine Alternator use: Reply #67 – September 02, 2015, 06:53:21 am I'm in Dave's camp. Thanks to the dash light for alerting me to shut down the generator. It's the 12kw Isuzu. Quote Selected
Re: Engine Alternator use: Reply #68 – September 02, 2015, 07:05:39 am Me too, I can barely feel it running when I am sitting still and not at all when I am rolling. Quote Selected
Re: Engine Alternator use: Reply #69 – September 02, 2015, 12:01:16 pm Don, with the noisy generator when driving.Check the rubber mounts under the generator. My 4 cylinder Kubota got very noisy one day last year and it was metal to metal clanging caused by broken rubber mounts. Quote Selected
Re: Engine Alternator use: Reply #70 – September 03, 2015, 07:07:20 am One more question, what is RLA? Needs to be 12 or more Quote Selected
Re: Engine Alternator use: Reply #71 – September 03, 2015, 07:36:26 am Quote from: Tim Fiedler – September 03, 2015, 07:07:20 amOne more question, what is RLA? Needs to be 12 or moreRunning load amps Quote Selected
Re: Engine Alternator use: Reply #72 – September 03, 2015, 10:24:28 am Run or Rated load amps is correct, I was actually asking what the value for his unit is, not a definition.😊 Quote Selected 1 Likes
Re: Engine Alternator use: Reply #73 – September 03, 2015, 11:01:57 am Thanks Wyatt, I have looked at the mounts many times and as far as I can tell visually, they appear to be sound. As I said, it isn't horrible, just noticeable. I think there is something rattling in sympathy with the generator frequency which adds to it though. I want to try and source some air spring isolator mounts for it but haven't got any leads yet on how to spec them out, other than weight of the unit and the mounting height dimension. I want to be able to add or remove air to find the mounts acoustically satisfying solution. Also, I will separate the radiator mounting from the generator as others have done with the 8KW units.DonQuote from: P. Wyatt Sabourin – September 02, 2015, 12:01:16 pmDon, with the noisy generator when driving.Check the rubber mounts under the generator. My 4 cylinder Kubota got very noisy one day last year and it was metal to metal clanging caused by broken rubber mounts. Quote Selected
Re: Engine Alternator use: Reply #74 – September 03, 2015, 12:52:51 pm Quote from: Tim Fiedler – September 03, 2015, 07:07:20 amOne more question, what is RLA? Needs to be 12 or moreThe Coleman spec sheet I found says RLA is 13. Quote Selected
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