EaglePicher PMG 200a @ 48v wiring ... Pinging Mobile Bob ....

[RJ]

So I picked up two of these units many years ago. Apparently they're from a telecom unit that had two running together in parallel for 400a @ 48v hooked up to a NG engine. Not sure if it was spec's at 1800 rpm or 3600 rpm. There is some information on the Micro Go gen forum but the site seems to be down. At least you can't get into any sub forms.

Anyway apparently these are rated for 48v @ 200a each. I'm really just in the testing phase but I haven't a clue as to how to wire these up and there is ZERO information about them online. I gather as most units like these utilize 3 phase AC output, my intention is to rectify the output to DC and run that into a charge controller/inverter.  Any help would be appreciated.

I posted this on the lister forum as well, as this forum wouldn't let me get into any of the sub forums for some reason. It now seems to be working.

Thank you.

[RJ]

OKay, Starting to get this figured out. I did some testing today. My little 1/3 HP motor with a 4" pulley on it and the PMG with a 5.5" pulley on it. So Motor spinning at ~1725 rpm the PMG is spinning ~1250 RPM I'm getting about 17v on each phase. So about 51v AC currently being produced. I have a 3 phase rectifier on order. Nothing fancy, 16 bucks off Amazon.

I'm no expert but that should give me about 68v DC. Plenty to charge a 48v bank and plenty of head room to ramp the speed up if needed for more current. Plan is to belt drive this to a lister 12/2.

[Tom Reed]

That might not be enough engine. The general rule is 2hp per KW. 200 x 48 = 9600w or almost 10 KW or 20hp. Do you have a way to limit the current?

[RJ]

Absolutely I won't have enough engine to tax this unit. That's the beauty of the setup. With a small (relatively) battery bank it will act as giant flywheel accepting larger short duration loads. During low load time the engine can spin down to a much lower RPM to maintain the battery bank charge.

[RJ]

That might not be enough engine. The general rule is 2hp per KW. 200 x 48 = 9600w or almost 10 KW or 20hp. Do you have a way to limit the current?

Forgot to answer your question, yes the plan is to use an MPPT controller from the rectified AC to charge the batteries/loads. I will use that to limit the current. 100 Amps or 4800 watts or so should be sufficient, or if I go by full charge on a 48v Lifepo4 pack that's ~56 volts or 5600 watts about the limit of the 12/2. Otherwise I would probably need to piggy back two MPPT controllers together. I don't think the complexity of two controllers is worth the trouble.

[RJ]

Well hiccup number one came to fruition 

Rectifier came in a day early, my hasty calculations implied the voltage would be the sum the of the three phases, this isn't correct its the L-L-L mean * 1.35, so in reality spinning at the current speed of ~1250 rpm I'm only getting about 25v DC. Which is interesting because I was told these ran at 1800 RPM. My small motor can't spin the head any faster without billowing some smoke. I have a larger motor but not the correct pulley's for them.

[Tom Reed]

That sounds like a good plan. My 6/1 puts out a steady 3 kw with brief loads of 3.6 kw when the microwave is on. I just went and checked to see what's available these days for PM 48v generators and there is quite a bit to choose from and some are dirt cheap! https://www.amazon.com/Alternator-Gearless-Permanent-Insulation-Horizontal/dp/B0BG47RMGV/ref=d_m_crc_dp_lf_d_t1_sccl_2_2/139-6785606-9829854?content-id=amzn1.sym.5d471845-5073-424b-b27b-c0676f48a016&pd_rd_i=B0BG47RMGV&psc=1

[RJ]

That sounds like a good plan. My 6/1 puts out a steady 3 kw with brief loads of 3.6 kw when the microwave is on. I just went and checked to see what's available these days for PM 48v generators and there is quite a bit to choose from and some are dirt cheap! https://www.amazon.com/Alternator-Gearless-Permanent-Insulation-Horizontal/dp/B0BG47RMGV/ref=d_m_crc_dp_lf_d_t1_sccl_2_2/139-6785606-9829854?content-id=amzn1.sym.5d471845-5073-424b-b27b-c0676f48a016&pd_rd_i=B0BG47RMGV&psc=1

Yes I have seen those, and yes they are cheap. However, I have yet to see any real world testing on them so I haven't looked at them with any real merit. If you come across any please do share.

[Henry W]

RJ,
When I had that thing running when mounted on the Ford LRG425, I believe it put out around 48 volts unloaded, un-rectified at 1800 rpm's. I can't remember.

If I remember correctly, wasn't there another PM head mounted on the end where the pulley is mounted?

Wow, it's been so long ago. Time sure flies.

Here is a link:
https://www.shawneepower.com/
Eric is the owner. He has the rights to build these. I spoke with him some time ago and he mentioned that they are somewhat different than his. Eric might be able to help you figure it out.

Bob G. has two of those PMG heads also. But, I'm not sure if they are the same as what you have.

Bob and Eric at Shawnee Power would probably be the most help.

Oh, Eric is a member on this forum.

[keith71]

That sounds like a good plan. My 6/1 puts out a steady 3 kw with brief loads of 3.6 kw when the microwave is on. I just went and checked to see what's available these days for PM 48v generators and there is quite a bit to choose from and some are dirt cheap! https://www.amazon.com/Alternator-Gearless-Permanent-Insulation-Horizontal/dp/B0BG47RMGV/ref=d_m_crc_dp_lf_d_t1_sccl_2_2/139-6785606-9829854?content-id=amzn1.sym.5d471845-5073-424b-b27b-c0676f48a016&pd_rd_i=B0BG47RMGV&psc=1

I dont like those amazon sellers.. They are saying that it puts 6000 watts..??

That is hard to believe.. I bet it is more like 350 watts.

[keith71]

Here is another about the same size and they are claiming 600 watts. And they throw in a rectifier as well..

https://www.amazon.com/Permanent-Generator-Alternator-Generators-Rectifier/dp/B0BJVTNM1W/ref=psdc_3754021_t1_B0BG47RMGV?th=

[keith71]

Well hiccup number one came to fruition 

Rectifier came in a day early, my hasty calculations implied the voltage would be the sum the of the three phases, this isn't correct its the L-L-L mean * 1.35, so in reality spinning at the current speed of ~1250 rpm I'm only getting about 25v DC. Which is interesting because I was told these ran at 1800 RPM. My small motor can't spin the head any faster without billowing some smoke. I have a larger motor but not the correct pulley's for them.

Depending on how your generator is wound, perhaps you need 2 three phase to single phase rectifiers instead of just one. I dont know enough either way just something to look at.. This video is long but if you skip ahead a bit to 27:45 minutes  you will see how he wires it. Might be because it is wired 2 in hand as Bob would say.. So there are 6 wires to connect in a regular alternator. 2 wires for each phase.. ??

https://www.youtube.com/watch?v=CL8W5hipaLM

[RJ]

RJ,
When I had that thing running when mounted on the Ford LRG425, I believe it put out around 48 volts unloaded, un-rectified at 1800 rpm's. I can't remember.

If I remember correctly, wasn't there another PM head mounted on the end where the pulley is mounted?

Wow, it's been so long ago. Time sure flies.

Here is a link:
https://www.shawneepower.com/
Eric is the owner. He has the rights to build these. I spoke with him some time ago and he mentioned that they are somewhat different than his. Eric might be able to help you figure it out.

Bob G. has two of those PMG heads also. But, I'm not sure if they are the same as what you have.

Bob and Eric at Shawnee Power would probably be the most help.

Oh, Eric is a member on this forum.

I have two units. My assumption is the one attached to the engine is the other unit that was mounted to the SAE adapter/unit I have. I'm going to try attaching it to a small engine I have that way I can really test the different RPM's and it what does what. I PM'd Eric here on the forum to see if he could chime in. I'm just not sure how linear the or not the voltage curve is for these units. I only have two data points. It looks to me that the PMG is wires in high wye configuration based on what I see how it's wired.

I'd be very curious to hear what Bob has to say about his units. There is zero information on the units in regards to part numbers etc....

Henry thanks for Chiming in! Appreciate it.

-RJ

[RJ]

Well hiccup number one came to fruition 

Rectifier came in a day early, my hasty calculations implied the voltage would be the sum the of the three phases, this isn't correct its the L-L-L mean * 1.35, so in reality spinning at the current speed of ~1250 rpm I'm only getting about 25v DC. Which is interesting because I was told these ran at 1800 RPM. My small motor can't spin the head any faster without billowing some smoke. I have a larger motor but not the correct pulley's for them.

Depending on how your generator is wound, perhaps you need 2 three phase to single phase rectifiers instead of just one. I dont know enough either way just something to look at.. This video is long but if you skip ahead a bit to 27:45 minutes  you will see how he wires it. Might be because it is wired 2 in hand as Bob would say.. So there are 6 wires to connect in a regular alternator. 2 wires for each phase.. ??

https://www.youtube.com/watch?v=CL8W5hipaLM

I'll take a look at it tomorrow. I was thinking while doing some yard work today. I wonder if I can rectify each phase on it's own then once in DC put them in series ? food for thought, it actually a lot of fun to start working on a project that's been on the back burner for over a decade. 

[veggie]

Here is another about the same size and they are claiming 600 watts. And they throw in a rectifier as well..

https://www.amazon.com/Permanent-Generator-Alternator-Generators-Rectifier/dp/B0BJVTNM1W/ref=psdc_3754021_t1_B0BG47RMGV?th=

Interesting little units.
What do you think is the efficiency of these.
Would it be in the 50% range like a car alternator? or maybe near 90% like an AC generator?