Derek up North Posted January 7, 2015 Share Posted January 7, 2015 I think this might be what you're looking for:- http://toyotamotorhome.org/forums/index.php?showtopic=4077&page=1 Quote Link to comment Share on other sites More sharing options...
zero Posted January 7, 2015 Share Posted January 7, 2015 Turning an alternator making over 70-80 amps with a standards single V-groove pulley is what defies physics, as i thought I'd stated. I've done sort-of the same to run a microwave oven. 900 watt microwave that draws around a max 1300 watts. If i have the microwave set on "high" it will trip off the 3000 watt inverter if just run from batteries (engine not running). But by starting the engine and letting the alternator charge while running the microwave - it works great with the engine at idle speed. But unlike an AC unit -the microwave only gets used for short periods of time. If someone wants to power an AC unit on a sustained basis from the alternator -and at idle speed - with a single V-belt drive - it's down to a AC unit drawing 60-70 amps @ 14 volts or less (less then 1000 watts.) A 5000 BTU window until will run at 600 watts and spike at around 1200 watts at start up. I assume something like that would work. Quote Link to comment Share on other sites More sharing options...
WME Posted January 7, 2015 Share Posted January 7, 2015 I've posted this before when the 12v A/C "idea" comes up. Newell who makes million dollar and up RVs. Spent a lot of time designing a 12v system to meet customer demand. These customers were willing to pay what was needed, after all whats a $75K when you just spent $1.2 million. Bottom line Newell couldn't do it SAFELY. They got the belts right, a separate giant alternator installed. The problem was just trying to run 200 amps @12v through correct sized cable. The slightest less than perfect connection resulted in overheat and FIRES. Newells answer just run the genset. Quote Link to comment Share on other sites More sharing options...
Vanman Posted January 7, 2015 Share Posted January 7, 2015 When we got my Dolphin back from the Toyota dealer I was sure the alternator belt was too tight. After loosening it up some it developed a squealing sound only when started up cold after sitting for a while. Went away before I could get the hood open. So I tightened the belt up a slight amount and it went away. Yes the dealer had it too tight, but too loose is not good either.Went thru an issue like this with my '71 Dodge van, the cooling system was totally inadequate and the final mod was replacing the stock "fan" with a big 6 blade fiberglass which pulled a lot of air. Had to tighten up the V belt to keep it from squealing at start up. After a run of new alternator bearings I loosened it up and lived with the occasional squeal. Belts easier to change that bearings.WME said; Newells answer just run the genset. As history has proven Tesla was right and edison was wrong Quote Link to comment Share on other sites More sharing options...
Maineah Posted January 7, 2015 Share Posted January 7, 2015 Yes the belt on the 4 cylinder Toyota's have got to be bow string tight or they will slip. The alternator pulley is small this allows the alternator to turn faster so that it will charge better at idle speed but it is an over drive approach and it makes it slip at high rev's. Quote Link to comment Share on other sites More sharing options...
zero Posted January 8, 2015 Share Posted January 8, 2015 Newells answer just run the genset. As history has proven Tesla was right and edison was wrong Neither Edison or Westinghouse (Tesla's boss man) were right or wrong as I see it. DC is still used for long-range electrical power runs and has some advantages over AC. The only fault I find with Edison is all the circus animals he electrocuted in public in an attempt to discredit alternating current. None of it has anything to do with what will work in an RV. ALL electric power made by rotating magnets starts out as AC. No way around that. The belt-driven alternator on a car or truck makes AC just like a gas driven generator. An auto alternator changes that AC to DC using rectifiers/diodes. A gas driven generator can either just supply that AC with no diodes (conventional). Or make that AC into DC with diodes and then run it into an inverter to turn it back into AC again (inverter-generator). The problem with using an alternator in a car or truck is size limitations and the belt drive. An auto alternator rated 100 amps is often 1/2 the size of a HD alternator designed to supply 100 amps on a continuous basis. So size is an issue. The other problem is belt drive. All alternators on cars and trucks are "overdrive" setups. I.e., a small pulley on the alternator driven by a much bigger one on the engine. They have to be since an alternator must turn at least 1600 RPM to do anything and an engine runs at only around 800 RPM at idle speed. Auto alternators are usually setup to run around 3 times as fast as the engine. The OEM pulley on a Toyota with a 60 amp alternator is 2 1/2" OD. That single V-belt drive on that pulley is capable of running a 1.2 horsepower load before the belt slips. 1.2 horsepower, 890 watts, and 63 amps @ 14 volts. If you have to stick with that single V-belt drive - a bigger pulley is needed to get more belt traction. Problem is - the bigger pulley also slows down the alternator and lowers the output at low engine speeds. Thus why dual pulleys is the best way to go when possible. A stock 2.5" pulley can run 1.2 horsepower, 890 watts, and 63 amps @ 14 volts. A 3" pulley can run 1.6 horsepower, 1200 watts, and 85 amps @ 14 volts. A 3 1/2" pulley can run 2.9 horsepower, 2200 watts, and 155 amps @ 14 volts. A 4" pulley can run 3.6 horsepower, 2700 watts, and 190 amps @ 14 volts. A 4.5" pulley can run 4.5 horsepower, 3325 watts, and 240 amps @ 14 volts. Here's a photo showing the size difference between a typical "continuous rated 100 amp alternator and a 100 amp auto alternator. Quote Link to comment Share on other sites More sharing options...
shibs Posted February 10, 2015 Author Share Posted February 10, 2015 This is the Bosch DENSO I bought off Amazon, did I get ripped off? I don't see a bosch anywhere... Quote Link to comment Share on other sites More sharing options...
Totem Posted February 10, 2015 Share Posted February 10, 2015 definately not ripped off if you got a cool dead mink with it! Quote Link to comment Share on other sites More sharing options...
Maineah Posted February 10, 2015 Share Posted February 10, 2015 Neither Edison or Westinghouse (Tesla's boss man) were right or wrong as I see it. DC is still used for long-range electrical power runs and has some advantages over AC. The only fault I find with Edison is all the circus animals he electrocuted in public in an attempt to discredit alternating current. None of it has anything to do with what will work in an RV. ALL electric power made by rotating magnets starts out as AC. No way around that. A DC generator makes DC granted it is pulsed as the poles are reversed by the commutator but it is DC the wave form does not cross zero the draw back to DC generators is the fact that the brushes carry the load and they do not do well at low RPM. Quote Link to comment Share on other sites More sharing options...
zero Posted February 10, 2015 Share Posted February 10, 2015 Technically there is no such thing as a mechanical “DC generator” that just makes direct current. Not unless someone has discovered a flaw in Faraday’s Law of Induction. This law describes how a changing magnetic flux is done by constantly reversing polarity. This causes the current to flip-flop back and forth. I.e., “alternating current.” Automotive “generators” are just modified AC producers. Compared to what we are calling “alternators”, generators are inefficient and make much less power for their size and weight. The cast-iron brushed generators like what were used in cars and trucks early 60s and back started to charge around the same shaft RPM as later alternators. One big difference was the pulley ratios. The old generators used bigger pulleys and as a result, ran slower. They had to since they were only capable of half the max RPMs most alternators can endure. Often they could not charge at engine-idle speed because they ran so slow. If a smaller pulley was put on them (like an alternator) and the engine revved to 6000 RPM - the generator could blow apart. A typical generator in a 1960 Chevy was rated a max of 30 amps and started charging at 1400 shaft RPM . Delco later replaced it with the 10SI alternator with a max of 72 amps and started charging 20 amps at 1600 shaft RPM. Delco later replaced that with an even more compact 11SI rated 95 amps max, and 40 amps at 1600 shaft RPM. Quote Link to comment Share on other sites More sharing options...
zero Posted February 10, 2015 Share Posted February 10, 2015 This is the Bosch I bought off Amazon, did I get ripped off? I don't see a bosch anywhere... I'm assuming that Amazon never really claimed it was actually made by Bosch, did they? Quote Link to comment Share on other sites More sharing options...
shibs Posted February 11, 2015 Author Share Posted February 11, 2015 I'm assuming that Amazon never really claimed it was actually made by Bosch, did they? The seller is a private seller who has a shop on Amazon, now the page description has changed, it mentions a Denso part # and claims to be compatible But it does say this: OEM(s): Denso Voltage: 12 Volts Amps: 90 Amps Regulator Position: 11:30 Polarity: Negative New or Remanufactured: NEW Approximate Weight: 12 lbs / 5.45 kg All the Denso parts I have bought were all marked clearly so. Quote Link to comment Share on other sites More sharing options...
shibs Posted February 11, 2015 Author Share Posted February 11, 2015 definately not ripped off if you got a cool dead mink with it! I am guessing the seller ran out of bubble wrap, he actually used the mink to wrap the alternator...I will have to toss the mink due to my allergies Quote Link to comment Share on other sites More sharing options...
Totem Posted February 11, 2015 Share Posted February 11, 2015 no way... REALLY? that came in the box? awesome! Quote Link to comment Share on other sites More sharing options...
Maineah Posted February 11, 2015 Share Posted February 11, 2015 Technically there is no such thing as a mechanical “DC generator” that just makes direct current. Not unless someone has discovered a flaw in Faraday’s Law of Induction. This law describes how a changing magnetic flux is done by constantly reversing polarity. This causes the current to flip-flop back and forth. I.e., “alternating current.” Automotive “generators” are just modified AC producers. Compared to what we are calling “alternators”, generators are inefficient and make much less power for their size and weight. The cast-iron brushed generators like what were used in cars and trucks early 60s and back started to charge around the same shaft RPM as later alternators. One big difference was the pulley ratios. The old generators used bigger pulleys and as a result, ran slower. They had to since they were only capable of half the max RPMs most alternators can endure. Often they could not charge at engine-idle speed because they ran so slow. If a smaller pulley was put on them (like an alternator) and the engine revved to 6000 RPM - the generator could blow apart. A typical generator in a 1960 Chevy was rated a max of 30 amps and started charging at 1400 shaft RPM . Delco later replaced it with the 10SI alternator with a max of 72 amps and started charging 20 amps at 1600 shaft RPM. Delco later replaced that with an even more compact 11SI rated 95 amps max, and 40 amps at 1600 shaft RPM. You are not getting the point an AC wave form crosses zero from + to - does not matter what the frequency is it still is alternating current. DC does not cross zero in the case of a DC generator it pulses + to zero back to plus never to - . Alternating current and batteries do not get along generators had no diodes their output was DC pulsed current.+ zero +. Quote Link to comment Share on other sites More sharing options...
zero Posted February 11, 2015 Share Posted February 11, 2015 The seller is a private seller who has a shop on Amazon, now the page description has changed, it mentions a Denso part # and claims to be compatible But it does say this: OEM(s): Denso Voltage: 12 Volts Amps: 90 Amps Regulator Position: 11:30 Polarity: Negative New or Remanufactured: NEW Approximate Weight: 12 lbs / 5.45 kg All the Denso parts I have bought were all marked clearly so. Even Denso sells parts that are from other makers and called "Denso partners." At least they tell you so when advertising. I've got several 120 amp and 160 amp Denso clones on Dodge vans. Made in China and less then $100 each and have been fine. They use external regulators like many new cars and trucks do now. But an add-on regulator is only $10-$15 if someone wants to use on some vehicle that lacks the computer to control regulation. The last brand-new 160 amp Denso clone I bought was just a few months ago and was $98. Quote Link to comment Share on other sites More sharing options...
Totem Posted February 11, 2015 Share Posted February 11, 2015 i go back and forth between new and reman. my most recent "brand New" alternator died exactly 1 day after warranty expired on my Dodge. incredibly enough had i had a autozone reman I could have still returned it as they had a better warranty. So its pick your poison really. play the reman game of constantly changing them out till lucky or buying new and knowing it craps on day 1 past warranty. One thing i always recommend is to force autozone or who-ever the reman is from to bench test it right out of the box prior to ringing up in front of me. I have literally had them fail tests right out of the box "brand newly " re-manufactured. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.