R175B/110-555

[scottpeterd]

ALright, I've been running more tests this week, and i'm not satisfied with the results.

I cannot get this baby to put out more than 40 amps.

The Sterling regulator appears to be working fine.  I've put a meter between the field supply battery and the field (on the negative side; I've got the alt/controller wired for positive side control).  I am pulling a pretty constant 4 amps into the field. The regulator starts off in it's initial 'reduce belt slippage' mode, then switches to full power mode.

The engine is spinning at about 2300 rpm (as measured with my optical tach).  The coolant is boiling; the alternator is getting plenty hot.  I've got 20 feet of 4 guage wire connecting the alternator to the battery bank, and i't not overheating.

Using my flexnet DC on my Outback setup, I'm getting 41a max initial output. After a bit, it settles down to between 25 and 32 amps.  The battery bank has had 180Ah removed from it, so it's sitting at a bit above 80% SoC.  The charging voltage looks correct at appx. 27.5v.

I'm wondering if belt slippage could be my problem.  The 'A' series belts are not seated fully in the Change Fa pulley, as they are 'B' profile.  Unfortunately, when I received my new 'B' series pulleyhere, it was actually an 'A' series, so I'm stuck with it for a while.

Any ideas?

[SteveU.]

Hey ScottP
" . . . the alternator is getting plenty hot."
This big case unint should not be at theses levels of 687.5 to 1127.5 watts.
You are not spinning the alternator fast enough to get the alt up into its efficient output range or for it's fan to be able to adequately cool it.
You are fo course using an alternator fan, yes?
Regards
Steve Unruh

[scottpeterd]

Steve,

It's got the bi-directional fan on it.  I am spinning it counter-clockwise, but according to Eric at Romaine Electric (where i got the alternator), that should not be a problem.

I don't know how to get the alternator to spin any faster.  The only pulleys I can get for this are the stock ones, at appx. 3" diameter.  The Chinese dealer here says there are no other pulleys available for the 175 engine.

The stock pulley on the engine is 4"; the 555 is 3", so I figure I'm spinning the alternator at about 3,000 rpm.  I would like it to be spinning at 5,000, but that's not going to happen with this setup.

Do I need to start thining about an intermediate pilow block/pulley setup?

Pete

[scottpeterd]

I just checked the output curve again in the spec sheet.  At 3,000 rpm, I should be in the 120-130A potential range.

[scottpeterd]

Ok, I think I have the problem.

I'm using the 555 re-purposed to charge a 24v battery bank.  I need to be spinning it at about 5,000 rpm for it to put out the amperage I'm expecting.

Since I can't find a bolt-on pulley, I'm probably going to be forced to go with an intermediate shaft and set of pulleys.

[yellowhead]

Ok, I think I have the problem.

I'm using the 555 re-purposed to charge a 24v battery bank.  I need to be spinning it at about 5,000 rpm for it to put out the amperage I'm expecting.

Since I can't find a bolt-on pulley, I'm probably going to be forced to go with an intermediate shaft and set of pulleys.

If it helps I have a very similar setup that I plan to use to charge at 48V. I solved the pulley problem by running a 8 rib belt around the flywheel to a 4.1"  * rib pulley from George at Utterpower. Gives me about 3.3:1 if I recall correctly. The pulley is held on the alternator shaft by a taper lock bushing. Now I haven't done much more than fire this up for a basic load test so I can't comment on its long term performance but it seemed to work OK ...

Simon.

[thomasonw]

. . . . .

The battery bank has had 180Ah removed from it, so it's sitting at a bit above 80% SoC.  The charging voltage looks correct at appx. 27.5v.

. . . .

In addition to spining it perhaps a bit slow, it seems to me (assuming you are using FLA batteries) that 27.5v is a bit low if you are at a 80% SOC.   I would think you would want to be in the Bulk/Acceptance  phase of recharging, and I would expect to see more like 29v.   27.5v seems to me to be more like a Float phase. . .

And given that you start out at 40A, and then drop down to 25a or so further supports that the voltage regulator is the limiting factor here - it is capping voltage a bit low, and the battery as a result is pacing the amps via its ability to accept a charge at that lower voltage.

For a '24v' system, I would expect nominal voltages (reference 25c) to be:
  Bulk and Acceptance:  28.8 - 29v  (Approx 2.42v / cell)
  Float:                        26.4 - 27v  (Approx 2.20v / cell)

Reduce each of these numbers by 0.06V (5mV/cell)  for every 1c the battery is above 25c.  (Sounds like you might be in a warm area   )


Do you have the remote battery sensing wires connected up to the Sterling?   If not, that could account for lower voltage  (Sterling sees 29v at the alternator, but that gets dropped to 27.5 by the time it arrives at the batteries).  A quick calculation:  40' of 4g wire (out and back) at 40A gives a voltage drop of 0.8v.

Perhaps take some voltage measurements, in addition to the current measurements, at the Field, Alternator, and battery.  That might help ID some issue.

-al-

[mobile_bob]

are you using my schematic for the repurposeing of this alternator?
if so the sense wire should be tapped onto the first 12volt battery

are you using a genuine 110-555jho or an aftermarket alternator?
i am not convinced that the aftermarket units are up to this repurpose, but i am not
sure because i have not tested them.

if it is an a genuine prestolite/leece neville 110-555jho, it will have avalanche diodes in it, and will likely need to have them replaced.

the reason being you are using such long cables from the alternator to the batteries, there is likely a couple volts drop and that will put you over the avalanche limit of the diodes.  they avalanche at about 30volts maybe a bit less, so if you are at 27.5 and have a 2 volt drop that puts the alternator trying to put out 29.5volts and that is too close for my comfort.  the diodes will need to be replaced with non avalanche types or you will have to reduce the length and/or increase the size of your cables.

again i don't know what the aftermarket alternators might use, they might avalanche a bit sooner?

you will need to get up over 4500rpm to get enough to do a good job of charging and cooling of the alternator.

when you mentioned a bidirectional fan, it makes me think this is an aftermarket alternator and not a genuine item, the 110-555jho is a 160amp 12volt nominal alternator as you know, but it comes with a directional fan, with an arrow dictating direction.  the alternator can turn either way and be ok but the fan is optimized for one direction.

maybe you have a genuine alternator and your supplier changed the fan for you to one of the earlier products bidirectional fans?  if so that is ok, but if the alternator is
not a genuine product, you will have to sort out the problems on your own, it might work just as well as a genuine one, it might not?  i just don't know.

if i can think of anything else i will post it later.

bob g

[SteveU.]

Hi Pete
Well there is a Changfa dilemma for automotive alternator driving alright.
I have a R185 and have puzzled over this same problem.
Suppied drive pulley is too small. Weird hub spacing needing a hollow offset center.
Ends up being a $200-300. USD minimum solution anyway a fellow would do it.
Large lathe then make up your own. $$$$ to pay out to do this. Or, machine down the existing and machine graft on a larger cast pulley outer. $$$ + $$$ for the pulley stock. Big enough cast pulley and a fellow could even machine up a three bolt through adapter plate. $$$ - $$$$.
Yellowhead/Simon's flywheel rim serpintine belt driving is certainly doable. To your Africa location the alt pulley & hub, a pair of belts (one for a spare) will be at least  a $$$ solution.
Your jackshaft idea would work. New parts though $$ + $$  + 2X$$ + $$ + will get you back up to $$$ quickly. Lay-about parts could bring this down. Compex, 2X the maintenaces, and more power loss on at best a 6hp?? system that will only ever be able to give you ~1800-2200 output watts.

Easy solution would be if one of the Chinese engine suppliers would just cast and machine up a stub shaft adapter so we could hub on out own pulleys for our own uses.
My one off inported into the US now engine sits as a backshelf unit now . . . waiting.
You . . . might just be best settling for the half full glass you have. Or shell out ANOTHER $$$ to try and intermitently fill the other half. You are discoving your battery bank will only ever allow full system output at the beginning of the bulk rechage anyhow.

Regards
Steve Unruh

[mobile_bob]

i did what Steve suggested on my 195
i went out and got a 1" ring plasma cut that was 9inches od and maybe 5inches id
then i had a step machined to register the ring to the flywheel, and then drilled/doweled and then drilled and tapped to bolt the ring to my 9inch pulley and drilled the pulley to access the recessed and covered allen head bolts that retain the assy to the flywheel.

end up costing me about 200 bucks or better if i recall.

George at utterpower.com used to sell stub shafts to fit the changfa 195 and 1115's not sure he did for the 175 or not, you might check with him on that.  a stub shaft adapter would certainly save a lot of grief and probably be a better fit at a lower cost too.

iirc he has the details on his cd if he doesn't have the stub shaft assy in stock,

bob g

[scottpeterd]

 AL, Steve, Bob

Thanks for the info and input.

Bit of background: I started all of this after ditching my 15kva 3p genset.  I live off-grid, even though I'm ouside Kampala, Uganda.  I live right next to Lake Victoria (at 3800' altitude).  I've got an Outback setup with an 800Ah battery bank and 4Kva PV array.  My batterys are tubular FLA from India.  My usage is appx 150AH per night (20% DoD).  During most of the year, the sun is great, as I'm about 30 seconds north of the equator.  The only time I use a genset is during the rainy (monsoon) season.  I live on rainwater, and to give an idea of our rains, I collect between 1 and 1.5 thousand litres a night from 1/4 of my roof.  My system is set so that the absorb voltage on the battery bank is 29.1v; the float is 28.0  During the dry seasons, I reach float by noon most days.  My biggest draw on the battery bank is a 400 watt water pump in my aquaponics setup. That runs from about 9am to 6pm.

I was motivated by Bob's white paper, as it seemed a much more efficient way to charge than the conventional AC gense, consideringthe max charge current I can get out of Outback inverter is about 60amps.

After hunting around in the states for a 555, I went to Eric at Romain Electric in Tacoma, Wa.  He got me an original Leece-Nevile 160A JHO. He special ordered the bi-directional fan. He went above and beyond to get this shipped to me before I left the states.Hightly recommend him.

I got the Chang-Fa from a fishing canoein exchange for an Yamaha outboard.

I had heard some quality issues with the Balmar regulators, so I decided to go with the digital Sterling kit. 

I then followed Bob's white paper.  The only real change neccesary to connect the Sterling PDAR was to hook the high voltage sense line to the voltage sense line, rather than to the alternator B+ terminal.  The voltage sense lines are run from the Sterling to the battery bank with a 1.5mm x 6m dual pair wire.  The main battery cables are 4 gauge battery cables from the states, connecting to the genset with an Anderson 100A connector.  I brought the main cable from the states, as it is just not possible to get decent large gauge wire here.

I ran some more tests this morning.  Here's the results:

Starting voltage for the battery bank: 25.3  The sump pump for the aquaponics setup was running, hence the low reading.  Warmed up the Chang-Fa for 15 minutes.

The Sterling did the low-amp startup for a few minutes.  The current to the battery bank started at 40A (as measuredby my Flexnet); then settled to 25A.

There was a voltage drop of 0.8v on the main battery harness.  V at the alternator terminals was 26.95; that at the shunt was26.17

[scottpeterd]

(cont)

The battery sense cable had a voltage drop of 0.25v.  V at the bank was 12.79, v at the Sterling was 12.55.  This held pretty stable for the 20 minutes I ran the test.  And it's about what I expected.

My goal with this setup is to get the majority of the bulk charge out of the way by mid-morning.  Then, even in the rainy days, I can reach full absorb at least once a week. Since I have to replace about 150Ah during a partial day, and to conserve fuel, I was hoping to recharge the bank in about 2 or 3 hours.  Hence my needs are to generate between 50 and 80 amps from the genset.

Obviously, I'm spinning the 555 too slow.  Fortunately, there are good (relative...) machine shops around here, run by Indians.  Their daily wage is about $10, so to do the flywheel mods would not be that expensive (there are advantages to living in the third world).

I was considering running the ribbed belt around the circumference of the flywheel, but: my 175 has a 13" diameter flywheel; my 555 pulley is 3".  That would spin the 555 at around 8,000 rpm, which is too close to max for my comfort (the Change-Fa maxes at 2300 rpm).

As to the intermediate shaft: I haven't discarded it completely, but as Steve points out, it's an additional loss on a 6HP engine.Plus I have to wait until my stateside visit this summer to get the pillow block and pulleys, and new belts.

That leaves me at presen with trying to fit a 6 or 7" pulley onto the Change-Fa.

I'll visit the local machine shop in the next few days to see what they can offer.  I can get the larger pulleys from the CHinese dealers (for the larger engines), but of course they don't fit the 3-legged bolt pattern of the 175 flywheel.

I think after this is done, it would be worth a write-up as a white paper ala 'Driving automotive alternators with Chang-Fa's'.  I suspect most of the members wanting or doing this setup will be running 24v/48v systems, and will need to up their drive speed.

Again, thanks for the help so far.

Pete

[scottpeterd]

Bob,

Now you've got me thinking.  You are right about the diodes getting close to their avalanch point.

If I were to go to an external 3-phase rectifier, I could kil two birds with one stone.  I could avoid the voltage drop by running the AC outputs from the 555 to the inverter rack and mount the external rectifier at that point.

Any recommendations as to an appropriate kit (with heatsink)?  I'm placing my orders before my annual home leave coming up in two months.  I'm certainly not going to find anything like that here.

I've found a 6 1/2 pulley.  The flywheel is down at the machine shop now, and we are figuring out the best way to mount it this weekend.

Cheers..

[mobile_bob]

my system (s195 changfa, driving twin 555's, a refrigeration compressor and an st7.5)

in early testing the avalanche issue came up, as long as i kept my charge line large enough and the distance short i could use the oem regulator, however i decided to try
one of the really cool 3phase rectifiers you see all over ebay and elsewhere.

i had nothing but problems,  and finally called the manufacture, they told me that they are built for industry and as such are made for 50/60 hz rectification, not 400 plus hz!  standard 50/60hz rectifiers at these amperage levels go into avalanche when they get over about 100 hz i am told, and they certainly will be in avalanche at 400 hz and above.. they turn your alternator into a very effective electric brake, burning belts and making lots of engine smoke and usually stalling small engine's.  you really don't want the rectifier to go into avalanche, it effectively is shorted and all sorts of bad things can happen real quick. luckily i didn't burn anything up, but then again i was standing right there when it happened and could quickly switch out the field and stop the problem before something went up in smoke.

i was instructed to contact a manufacture that made the same form factor but using fast recovery diodes,  i never followed up on that.

what i did do was go back to RE electric and bought a replacement set of hd diodes to replace those in the 555, they are rated at 200piv and iirc 70amps each, 3 pos and 3 negatives and i put them in a set of heat sinks out of an old 555 i had laying around and installed them... problem solved.

they were about 6 or 7 bucks each iirc

my thinking was in i wanted a remote mount, i would just make up a heatsink and use those automotive aftermarket diodes, and just press them in.

fwiw
for my drive system, i used a 4 groove A/B type steel pulley, it was a Q bushing type
but i had a donut adapter ring cut and machined with the step to fit the flywheel
iirc the pulley diameter is 9inches and the dual A belt pulleys on the 555's are 3inch
at 1800engine rpm the alternators are turning around 4800 to 5000 rpm ( i don't recall the exact rpm as i don't recall the exact pulley diameters) anyway i use twin AA belts, those being the hexagonal section belts that can run in serpentine applications.  i did this so that i would not have trapped belts requiring me to remove the direct drive st7.5 genhead to replace the alternator drive belts.  this enables me to change the two drive belts in under 2 minutes, so long as the machine is accessible.

to the original poster
once you get the alternator rpms up to around 4500rpm, i think you will find the output to be much more inline with what you are after, bearing in mind the amount of amperage delivered will be dictated by the loads and demands of the battery bank. the amps will fall off as the battery nears full charge, so even then you might not see much more than 40amps if the battery is nearing full charge.  i am very certain that you are not having belt slippage problems if you are using two belts (A section) and things are tight, and once you get the larger engine drive pulley machined and installed you will be golden, no problems with slippage either, again provided you are using quality components, things are tight, etc.  if you have any doubts, buy AX section belts to start with, and make sure they are a matched set!

bob g