A new surplus Stamford Newage 7.5KW, 2 pole 3600RPM. He's got a lot of them. My main concern is if it's a two bearing unit or not, I'm sure I can adapt a pulley attachment to it but I dont know how well it'll take a side load.
http://www.ebay.com/itm/7-5-KW-Stamford-Newage-Generator-End-New-Surplus-/230557910201?pt=BI_Generators&hash=item35ae5284b9
Thoughts?
Edit to the edit:
It's 3 phase - but according to the wire diagram they can be configured to double delta single phase (??). As I want to rectify it to DC and feed a battery bank I'm unsure how well this'd work.
They are single bearing and the 2-bearing conversion kit is no longer available.
If you are going to make DC out of it, 3 phase is the way to go IMO...
3 phase is a dream come true for DC charging, that's why auto alternators are 3 phase. Otherwise you usually have to find a monster inductor (usually a transformer primary or secondary) to filter.
If you need to change the voltage, however, three phase can get expensive, since you need 3 transformers. What's your planned charging setup ?
Can these be set up for single phase? If so that would be a heck of a deal. I can easly make a 2 bearing adapter for it and if I ever had a need for DC or 3 phase I could have my cake and eat it!
Quote from: BruceM on January 20, 2012, 11:53:14 AM
3 phase is a dream come true for DC charging, that's why auto alternators are 3 phase. Otherwise you usually have to find a monster inductor (usually a transformer primary or secondary) to filter.
If you need to change the voltage, however, three phase can get expensive, since you need 3 transformers. What's your planned charging setup ?
I'm going to be feeding the rectified DC to a Midnight Solar 200 charge controller pushing electrons into a 48V battery bank.
I want 120V single phase in case something goes wrong during a long term emergency I can feed the load directly instead of going through an battery bank/inverter. I suppose I could leave it 3 phase and then rewire it if I ever need single phase. According to the maintenance manual I downloaded it'll raise the efficiency from 67% (1p) to 73% (3p).
I've been looking for the 3 parts to convert it to a 2 bearing gen head, but can't find them like Hwew said.
I'm experimenting w/ a MN Solar 200 right now, w/ Listeroid and ST 7.5. Using a big inductor. Wish it was 3 phase, but need regular AC too. Can't have it all. It works find but I'll be able to give you some better data and initial setpoints when some capacitors arrive from Digikey.
Are these any good? I have viewed them many times. My neighbour is a retired machinist and could easily make me a conversion kit to 2 bearing for at most a couple hundred bucks.
Based on the manual, the Midnight "Classic" 200 is designed for a rectified AC power source, in the "Legacy Perturb & Observe" input mode. They specifically mention a Lister engine with rectified 3 phase. No mention of single phase, but perhaps Marcus knows the scoop on that.
You might have some issues with it's power point tracking design if you don't use that mode, it will periodically bog down your generator as it tries to find the optimum load. I'm sure you can put a limit on the charge current, that might solve that problem as well. No doubt the company has lots of folks using them for rectified AC charge regulation, and their tech support should be able to suggest the most popular arrangement for a "swings both ways" (PV or Generator) setup, assuming you don't want to push buttons to run your backup generator for charging.
Sure looks like a good job of design and engineering. If the world ever wakes up and starts specifying EMI limits on off grid power systems, I'm sure Midnight will be in the lead with a low-EMI product line.
Rectified 3-phase certainly would be best to feed any MPPT charge controller. You can see how I'm trying to get rid of ripple and resonance from single-phase w/ caps on other threads.
One of our members here, Halfcrazy, is a tech support manager at Midnight Solar. He runs a Listeroid w/ single-phase ST head w/ a Classic 200 for charging. But he also parallels two 5000+ uFd capacitors. He sent me a pdf file with his setup. Wonder if I could post it here. Is there a way to post a file? Or I can just upload it to my server later and make a link here later tonight. Not trying to hijack this thread but this is your future intent for this gen head, no?
I've tried the "microhydro" mode and the "legacy" mode on the Classic 200. Both bog down my 6/1 to the point of almost stalling, which I didn't like. So I just use the %VOC mode at 62% and set the amp limit to 50. I suspect these numbers will change when I add a few large capacitors. Don't know if always hitting the amp limit is OK or if will cause long term damage.
Marcus
Hmmm, I never considered FABBING a end bearing. It shouldnt be all that terribly hard.... And if it doesnt work I'm only out $250
Shipped to Oregon = 150.00 do I need this I ask?
http://powertechengines.com/NewageData/Manual-Stamford-BC164-184-english.pdf
http://literature.puertoricosupplier.com/024/TU23763.pdf?CFID=87579322&CFTOKEN=36070555
We purchased a couple crates of these some time back... good people to deal with. I have not figured out how to accommodate a second bearing with that shaft flange as supplied - as of yet.
dieselgman
I still have the contact number from a person at Stamford/Cummins when I inquired about these about 8 months back. I'll see what I can find out. As I mentioned before, the 2 bearing kits are no longer available. I will contact him and see if I work somthing out.
Henry
Quote from: hwew on January 21, 2012, 08:35:26 AM
I still have the contact number from a person at Stamford/Cummins when I inquired about these about 8 months back. I'll see what I can find out.
Henry
Thanks Henry, the number I found for their USA operations (Newage Ltd) is 1-800-367-2764, they're out of Fridley Minnesota. I hadnt called yet to ask for parts 9, 10, 13 from page 36 of the BC162 manual (2 bearing section). Those parts are the only ones that are different from their single bearing that I could tell.
From what I understand the Stamford Newage gen heads are premium quality heads.
http://www.frontierpower.com/stamford/bc-162.pdf
Actually a 12 kw generator in prime service. Major bargain if they can be adapted.
A good parts list from Cummings Generator
https://www.cumminsgeneratortechnologies.com/www/en/support/aftermarket/PartsLists/BC_PartsList_01.pdf
40 D.E. ADAPTOR BRACKET SAE 5 . . . . . . . . . . . . . . . . . . .130-21602 . . . .1
41 D.E. SCREEN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .130-21325 . . . .2
44 D.E. BEARING KIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45-0363 . . . .1
45 D.E. ENDBRACKET . . . . . . . . . . . . . . . . . . . . . . . . . . . .130-20773 . . . .1
46 ADAPTOR KIT SAE 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . .45-0719 . . . .1
. . ADAPTOR KIT SAE 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . .45-0619 . . . .1
. . ADAPTOR KIT SAE 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . .45-0620 . . . .1
. . ADAPTOR KIT SAE 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . .45-0621 . . . .1
Using caps alone for filtering rectified single phase power has some issues; your power factor is crap, since most of the load is on the leading top quarter of the waveform, only above the capacitor voltage. If your generator head is way larger than the total load, and your other loads aren't fussy about waveform, it will work fine, though fuel efficiency will suffer some. Your DC voltage output is about 1.4x the AC input RMS voltage. This is the cheapest solution, usually.
If an inductor is used for primary filtering on rectified single phase, with capacitors as secondary, you can have an excellent power factor, no waveform distortion to affect other loads, and least loading of your generator. Your DC output voltage = AC input RMS voltage.
Recently was messing with a design for a 120V battery bank charger that used 3 small caps, dynamically (solid state) switched in combination before the primary inductive filter to regulate the charge current. I had tested this on grid power and it worked like a champ. On my ST-3 this same design was a total bust at 1200 watts of charge and above. The AVR didn't regulate the voltage properly as the waveform was trashed. Between the low voltage and trashed waveform, I got control relay chatter. I redesigned the AVR using a true RMS chip. Worked, but I had no capacity left for other loads due to poor PF, and the RMS chip was so slow in responding that there was no more flicker compensation, so my shop heat/light floods were driving me buggy.
I finally abandoned my not so "brilliant, simple, patentable" switched capacitor design with custom printed circuit boards :'( and went to a homebrew motorized Variac and straight inductive filtering. It's (embarrassingly) low tech and simple and works like a champ.
Quote from: Simtech on January 21, 2012, 09:49:42 AM
A good parts list from Cummings Generator
https://www.cumminsgeneratortechnologies.com/www/en/support/aftermarket/PartsLists/BC_PartsList_01.pdf
40 D.E. ADAPTOR BRACKET SAE 5 . . . . . . . . . . . . . . . . . . .130-21602 . . . .1
41 D.E. SCREEN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .130-21325 . . . .2
44 D.E. BEARING KIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45-0363 . . . .1
45 D.E. ENDBRACKET . . . . . . . . . . . . . . . . . . . . . . . . . . . .130-20773 . . . .1
46 ADAPTOR KIT SAE 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . .45-0719 . . . .1
. . ADAPTOR KIT SAE 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . .45-0619 . . . .1
. . ADAPTOR KIT SAE 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . .45-0620 . . . .1
. . ADAPTOR KIT SAE 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . .45-0621 . . . .1
Been through this. I spent lots of time over 8 months ago doing exactly what you are trying to do.
If you look, the stubshaft is not listed. That is the part that is no longer available and is not listed in the parts list. They have been all bought out by a company in Mexico. They are no longer manufactured. And Cummins is not willing to have them manufactured and would rather see these gen-heads rust away.
Henry
Thanks hwew, I'll quit barking up that tree and just focus on fabbing an end bearing housing. It doesnt need to be pretty, just work well enough to hold the side load of a pulley and belt.
I tried to call Cummings today and they're closed anyway.
Bruce, could you maybe expound on the specifics of your rectifier/filter? Perhaps a circuit diagram?
It may not be too difficult to turn out a stub shaft for that application... just a thought.
dieselgman
Well I been holding off on writing this. I have a contact number from the engineer that has helped find the stub shaft info that is no longer available. What I am planning to do is see if it is possible to release a drawing of the stub shaft. Since it is obsolete and they have no intrest in manufacturing them I feel why not ask. They would not be loosing anything. If they would release a drawing I have the means to get them machined on a C&C.
Henry
IMO the shaft is the easy part....the end plate to carry the bearing will take a fair size lathe and material to fabricate. Not a stopper just some fab and setup.
This is true.
Lets get the price on all the other parts listed.
I'll see if I can come up with a drawing for the stub shaft than there would be no guessing or trial fitting. Just get it machined.
Once the cost is figured than members can decide if it is worth it.
Henry
Simtech,
My AC charger is part of a larger custom system which I designed for a 120VDC (nominal) battery bank. Each 12V battery in series has an individual temperature controlled, 3 voltage shunt regulator (float, bulk/absorption, equalize), with shunt current feedback. The PV controller is analog; it will charge at 3 preset net charge currents. (Float 0.1A, Bulk- Max PV, Absorption- 2.5A)
The Battery Bank Charge Controller is a Picaxe 40X2 based board which I designed. It manages the PV charge controller, the 10 battery shunt regulators, and the Variac control for the AC charger- adjusting it once per second as needed to keep the battery shunt regulators from overheating during the bulk charging. It presently stops charging when the batteries are each at bulk voltage and net charge current is down to 3 amps. That's not full, but it's close enough that even on a dark day the PV system can finish the charge.
The two stage inductive filtering of my AC charger (see schematic below) is not necessary, but I was trying to reduce the 10Hz "Lister flicker", which I find bothersome on lower wattage incandescent lights. I don't find it bothersome at the present level. 60Hz ripple is down to about 30mv on 145VDC at 10 amps. 10Hz variation is about 1.4V.
If I had been feeling more ambitious I could have used active linear regulation to get rid of the 10Hz Lister Flicker, by just regulating to a steady voltage a few volts below the peak. That could eliminate the second inductor, and reduce the size of the primary inductor as well. But the big toroidal transformers I used were surplus ebay buys, and this is just a prototype.
Since you're planning on using a PWM charge regulator, all you need is bulk DC within it's input specs. The Midnight 200 can handle rectified 120VAC in terms of peak voltage. No filter needed for 3 phase. For single phase, you just have decide on inductive vs capacitive filtering.
Bruce: Oy! Thats a bit more complicated that I want to go, I ran the numbers for a 4000W combined inductor/capacitor filter and I came up with 19 Henrys for the inductor. Is that right??! Thats a pretty big inductor.
I havent mucked about with component level electronics in a long time so I could easily be wrong.
Hi Simtech,
Yes, doing a 120V battery bank charge controller properly is a bit involved. You can't just charge the bank as one big series battery and hope that frequent equalization will keep all the batteries in sync. There is just too much variation in individual battery charge acceptance and internal resistance. you must apply the individual battery shunt regulator approach used by the electric car folks. There are lots of advantages of this method, and higher voltage banks in general, but I won't go into that.
Choke size isn't anywhere near your multi-Henry figure. It will be a small fraction of a Henry, depending on your allowable ripple. A free program, PSUD is good tool for doing a thorough design of an LC single or multistage filter.
Also:
http://www.toroid.com/custom_transformers/dc_filter_chokes.htm
has a table for selecting values.
The rule of thumb by audio folks is that the critical choke size (minimum for primary filter) is L=E/I (where I is in milliamps).
Here's the two critical equations:
The minimum current is aproximately equal to:
Imin (mA) = [Vin(RMS)] / [L(H)]
You can calculate the ripple of the choke-cap system as follows:
[Vrip(RMS)] / [VDC] = 1 / [ 6 * sqrt(2) * 2 * PI * f * L * C]
L = inductance
f = AC line frequency
C = capacitance
VDC = DC voltage at cap
PI = 3.14...
For a filter in front of the Midnight 200 classic, for a single phase generator, you would want a simple LC filter, unless you have excess capacity and are going to just do capacitive filtering. In that case if you know your allowable ripple voltage:
Delta V = I / [2 * f * C]
Toroids are much less prone to DC saturation, so I always use surplus toroid transformers for chokes. The utter BS/cheap bastard method I often use is to just make sure the winding you use as a choke is rated for more than the DC current. You don't need a toroid as large as the primary transformer, but it won't hurt. I've not had trouble with DC saturation using the BS/cheap bastard method and toroid transformers. A conventional E-I core transformer is another matter altogether; they can't normally be used unless they have an air gap, due to DC saturation.
If your head will do 3 phase, 120V, with a common ground to the battery bank negative, you don't need any filtering at all, using the Midnight 200 classic charge controller, according to their literature. If a single phase generator head is used, ask Midnight how much ripple is allowable. It will probably be quite large, feeding a 36 or 48V battery bank from 120VDC (nominal). You might be able to use a single 1000 watt toroid transformer core, using a low voltage secondary winding for the choke.
Quote19 Henrys for the inductor
The inductor I'm using w/ my Classic200 is no where near that large and it works.
QuoteDelta V = I / [2 * f * C]
Bruce: So for 1 V ripple voltage @ 60 Hz and 40,000 mA (i.e. 40 Amps) --> C = 333 (?) microfarads?
Wish I had an o-scope. I just ordered 2 x 3000 microF caps from Digikey. Probably way over did it.
Here is the pdf that Halfcrazy (Midnight Solar employee) gave me describing his setup for charging 48 V batt bank w/ a Classic:
DC_charging_w_listeroid.pdf (http://www.docbryner.com/misc/DC_charging_w_listeroid.pdf)
Very interesting post Doc. No inductor just rectify the AC and some caps. Interesting his 6/1 roid has what look like 1000 rpm flywheels.
Hi Marcus, Alas, the equation for ripple yields 330K uF, not 330uF. 40 amps is a hell of a current to slam into a capacitor bank. In fact, when I run this on PSUD with a realistic ESR for the capacitor, a it shows 3-7 volts of ripple depending on the generator impedance. This is why as currents go up, you always see LC (inductor first) filters used.
The same 40 amp, 120V put into an LC filter with a 0.1H choke and 3K uF cap (both reasonable values) gives you about 1V of ripple (depends on the ESR- equivalent series resistance of the capacitor). I was lazy and ran this on PSUD. Note that a higher ripple is certainly acceptable, so the capacitance could be less; 1K uF would give you 3 volts ripple. 0.01H or 10mH for the choke would give you 10V ripple.
Edit- I just ran something like Halfcrazy's capacitor only filter. With a single 10K uF capacitor with 38mohm ESR (a $40 cap) I get 20 volts of ripple at 25 amps. Since his setup is acceptable to the Midnight 200 Classic, I guess 20V of ripple is just fine. He didn't state his measured ripple voltage.
I got an email from the engineer that I worked with a while back. The two bearing generator head has a completly differant rotor shaft than the one bearing generator head.
I stand corrected about the stub shaft that Stamford had available for the single bearing head. The stub shaft was made by an aftermarket company to convert these heads to a 2 bearing. But there were other special parts needed to make it work. The engineer does not know the company that made the special kit.
The Engineer emailed a colleague in Stamford and hope to hear back from him in the morning. Hopfully some good news will be coming.
Henry
Quote from: hwew on January 23, 2012, 06:15:49 PM
I got an email from the engineer that I worked with a while back. The two bearing generator head has a completly differant rotor shaft than the one bearing generator head.
I stand corrected about the stub shaft that Stamford had available for the single bearing head. The stub shaft was made by an aftermarket company to convert these heads to a 2 bearing. But there were other special parts needed to make it work. The engineer does not know the company that made the special kit.
The Engineer emailed a colleague in Stamford and hope to hear back from him in the morning. Hopfully some good news will be coming.
Henry
Thanks for looking into this again, those gen heads would be a great resource.
Just got an email from the engineer yesterday and nothing is available.
Henry
Oh well, I still think I'm going to get one and tinker with it. The second bearing might be held in place with JB weld and strap iron when I get done with it but it's still worth a look.
Fun too.
Just need a good size lathe and some steel and aluminum blanks to experiment with... shaft extension seems to be the problem area.
dieselgman
If someone here can get a kit made at a reasonable price to fit those generator heads there might be some money to be made.
Henry