200 amp Small Frame Brushless Alternator - Look OK?

[dkenny64]

Originally Posted by GrowleyMonster

I would guess that the typical 5kw brushed motor used for propulsion would under normal sailboat use patterns would require new brushes every 10 years or so. So not a big deal. They are not expensive and not so difficult to change. However, explosion potential must be considered. If you have any gasoline or propane on board you must use a brushless propulsion motor. No propane or gasoline? No worries. One benefit of going with a brushed propulsion motor is if your controller goes north on you, you can connect directly to your bank for emergency propulsion, maybe split the bank for lower voltage and lower speed. Can't do that with a brushless motor. Why I carry a spare controller. It is also easier to DIY a controller for a brushed DC motor. It is just a PWM power supply. Brushless motor controllers are much more complex. There is a huge market for SCRs and MOSFETs for DIY brushless controller designers and tinkerers. They blow up an owful lot of power transistors.

hum.. I thought he was asking about alternators..power generators..not a motor..power consumers.. I guess I'm off topic..


-dkenny64

[GrowleyMonster]

Originally Posted by dkenny64

hum.. I thought he was asking about alternators..power generators..not a motor..power consumers.. I guess I'm off topic..


-dkenny64

LOL sorry... seems to have been a little bit of topic creep.

[bcboomer]

All-Tek ran the alternator at 3000 RPM and the output was 135 amps cold and 107 amps hot. Seems good to me.

I'm going to use 1 of the "smart" regulators so one question I have is whether they should leave the internal regulator in place or run the wires out.

Did I mention it is only 320 CAD?
Similar performance to 1000 USD units I see advertised.

Can't see a downside.

[witzgall]

My only suggestion is to think hard about putting anything in that requires you to modify the alternator or the mount to make things work. Being able to purchase something off of the shelf that fits can be a lifesaver, if things break down far from home, or right before you want to take the boat out for a week. I would also make sure that the alternator can be regulated externally, which will give you better performance in almost all scenarios.

As a comparison, a Balmar 120a 6-series alternator is rated at 105a hot at 3000 alternator RPM. It is a design that can be worked on by any alternator repair shop, spare critical parts are available, and carrying a spare and swapping while far afield is easy. Although I work for Balmar, I actually had this exact alt on our cruising boat years before I started to work for the company. We did a middle of the Bahamas swap after an electrical issue caused by spraying salt water on the back of the alt. It was a stress-free swap, which was important anchored off of an uninhabited island!

Chris

[Jammer]

The alternator the OP is asking about appears to me to based on the Delco AD-244.


https://duckduckgo.com/?q=delco+ad-2...ages&ia=images


General Motors has used the AD-244 in, well, millions of trucks and SUVs. They're highly regarded automotive alternators, nothing particularly unusual about them. By automotive standards they are considered large frame.


The standard design for brushless alternators is to have a pair of exciter windings (rotor and stator) with a diode rectifier on the rotor, that are separate from the main rotor and stator. The field voltage is then applied to the stator of the exciter. A proportional AC voltage is then produced on the exciter rotor, and rectified, and used to power the main field winding -- which, just as with a design with brushes or slip rings, is also on the rotor.


The biggest problem with all this is that it takes up a good deal of space, more space than would be required for brushes or slip rings. Therefore, brushless designs are not as compact. There is also more to go wrong since the diode bridge and field windings are generally not repairable. While brushes are a wear item that requires periodic replacement, they last a very long time, and are usually not difficult to replace.


There are also some hybrid designs out there that combine a permanent magnet rotor with a relatively small field coil.

[bcboomer]

It can be regulated externally, All-Tek will run the wires out. I've seen reference to adding an external regulator and keeping the internal one in place as a back-up. I don't know how involved that is but hopefully I can find it on the web if I go that way.

As far as mounting is concerned, it is available with a single 2" mounting foot so I'll take the engine bracket to the machine shop and have it modified or replaced. There are also adapters but that may result in misalignment issues.

Finally, it is 1/3 the price of a Balmar and has no brushes to wear. All-Tek is an industrial manufacturer in the oil patch so I believe they are pretty reliable and tough. I've had a small amount of experience in that market and they wouldn't still be around after 6 years of making these units if they weren't reliable.

If it is based on the AD-244 it is only 5.25" in diameter and 6.75" long. I have room for that but I'll ask All-Tek on Monday to be sure.

[dkenny64]

I don't the worry about the brushes wearing out??
they aren't a high current item in an alternator..they run the field..
10-15amps or so...


for reference..my truck 200amp alternator...replaced about 200K miles ago.
thought it was bad..might not have been.. is doing fine.. that's about 6000 hrs on an engine... nothing done to it...


I know for a fact brushes are easy to change on a small frame like a delco 10si or 12si..


so why go with brushless other than in an explosive environment..


-dkenny64

[bcboomer]

I'm not concerned about brushes but this happened to be the biggest bang for the buck I have seen
1/3 the price of anything else that I can get specs on. All of the high amp Delco clone sellers I contacted had no idea what they could actually put out continuously. One said that they could not be used to recharge a depleted battery. I think their target market must be the kids with megawatt amps and subwoofers.

[john61ct]

Yes markets like that decide exactly what you want before talking to vendors.

[john61ct]

Fact is a small-frame unit will never be predictable past 1/3rd its rating.

Heat is too big a variable.

[dkenny64]

john61ct,
I don't agree...
they're used in cars and trucks all the time..
I know a guy that uses a pair of 200amp, using 2 vbelts on each alternator,,
to charge his batteries and run his 12V water maker. the water maker uses a 2hp, 12Vdc motor..or about 360-380amps...
its possible..
no he doesn't have an extra cooling setup to keep the alternators cool..


-dkenny64
ps I'd love to convert my single vbelt to a serpentine...and keep the alternator output the same...just to keep the belts from failing..I only have 90amp alt...

[bcboomer]

Are they small frame?
Any idea what brand?

[dkenny64]

bcboomer,
if you'd like I can find out..
he mounted them on a small extra diesel in his boat.

also mounted a fridge compressor to keep the food cold..
its was about 12HP diesel..


-dkenny64


ps I've ask the make and model he used....

[bcboomer]

I'd appreciate it.

[dkenny64]

Originally Posted by GrowleyMonster

I would guess that the typical 5kw brushed motor used for propulsion would under normal sailboat use patterns would require new brushes every 10 years or so. So not a big deal. They are not expensive and not so difficult to change. However, explosion potential must be considered. If you have any gasoline or propane on board you must use a brushless propulsion motor. No propane or gasoline? No worries. One benefit of going with a brushed propulsion motor is if your controller goes north on you, you can connect directly to your bank for emergency propulsion, maybe split the bank for lower voltage and lower speed. Can't do that with a brushless motor. Why I carry a spare controller. It is also easier to DIY a controller for a brushed DC motor. It is just a PWM power supply. Brushless motor controllers are much more complex. There is a huge market for SCRs and MOSFETs for DIY brushless controller designers and tinkerers. They blow up an owful lot of power transistors.

again..
alternator generators power.....
a motor consumes power...
I ask about an alternator... not a motor..
not the same thing...
so how does your reply answer my question? if not why quote it?


-dkenny64