Observations on a 'High Output Alternator' installation on M

[Larry DeMers]

Greetings Everyone,

I am winding up the installation of a Balmar 80 amp, externally regulated alternator with 4in. Balmar 'Special Volvo' pulley, and wanted to tell you about the experience so far.
First of all, the installation is taking place in a 1983 CD30 with the Volvo MD7B workhorse. Second of all, when estimating the time required (and effort it turns out) for completion of this work, multiply by Pi (3.1416...), at least. Finally, you will need a trusty side-kick to help, as it is definitely a two person job..if for no other reason than for company ;^).

My first attempt, partially successful, was with the Balmar 91-75. This is a small frame 75 amp alternator, fed by a single 3/8 or 1/2 in. belt. This alternator has a maximum rpm of 10,000 rpm..remember this little number for a bit later.
We spent 4 hours removing old alt., retaining all screws, nuts, washers and belt, retrieving from the bilge dropped socket and 1 nut, driving to the hardware store (retrieval did not work), and installing the alternators and cleaning up. We spent another 2 hours mounting and routing the Balmar ARS4 3-stage regulator.

Started the engine, and ramped up to 1500 rpm, and monitored the ARS4's led indicators for proper cycling thru the normal menu of status points. All reports well. The LINK 2000 is monitoring the on-purpose 20% discharged house bank. There is a 45-60 sec. wait for the regulator to turn on the field current, allowing the engine to get up to speed, oil the bearings, and settle out a bit before it ramps the field current up to full output for the discharge you have. Mine went from a discharge of 1.9 Amps to a charge of 31 amps slowly, over 20 seconds or so. The engine definitely feels the 2 or so hp being drawn from it, as the tone deepens, and it feels like it is under load a bit...not too much, but noticeable.

Then I begin to hear a medium pitched whine that rises/falls as I change rpm up and down. Loose belt? Shut it down, and hop down for a check of the belt.
The alt. tensioning arrangement that I used is not the best, but all that I could figure out without having a tension arm made for the installation. I used the existing tension arm as well as one bought from Balmar, with the two attached end for end with two 5/16 in. machine screws and lock/flat washers and nylock nut. This places the arch of the tension bar at the right place for the alternator to contact it perfectly.

Oh yeah, alignment of the alternator was a real fun time. It IS NOT a direct drop in. The two inch foot model will be too big, so get the one inch foot model, and use shims (provided with the alternator)to take up 7/8 inch in the lower foot attachment point.

Back at the ranch..
I dropped down in the engine compartment to see if the belt was tight, and it was very tight. So we dug out the tools and tightened it even more..now bar tight, and far beyond what I know automotive alternators require. But Balmar has instructed me to use a 12 in wrench and try to turn the alternator's shaft against the engine (dead of course). If it can be moved, retighten it. So now I put enough pressure on the belt to actually stretch it a bit, and then we try the test over again. Nope, she still starts a higher pitched screeching that really sounds like dry bearings more than a belt.

Talked with Balmar, and they think it's a belt problem, but admit that bearing problems would sound the same way. So they sent me a new alternator, but better. It's a 71-80, an 80 amp high RPM alternator made for the Argentina market, due to their use of higher rpm engines (according to Balmar). This alt has two fans inside that cool the alternator better, allowing a maximum rpm of 14,000. This will fit the rpm range of the engine better.

The issue of rpm and heat turned up while talking with Blamar. We worked out the rpm at the alternator, which is a ratio of the flywheel diameter:alternator pulley diameter. I had ordered the alternator with the special Volvo 4 in. pulley (it's machined..and balanced, as these rpm's are too high for a stamped alt.)
Turns out that the rpm was as high as 10,000. The alt. was very warm to the touch.

So this weekend..weekend three of this episode, I'll be trying a looser tension first, then if that still results in the bearing sound, we'll replace the alt. with the new one just delivered.

Have to admit that it is fun watching that battery fill up 2-3x faster than with the old automtive alt. though (we did use the alt. at non-noisemaking rpm's for last weekend). [fun?! -watching a battery charge? jeesh, I've got to get a life..]

I'll write more when this is resolved.

Cheers!

Larry DeMers
DeLaMer
Cape Dory 30



demers@sgi.com

[Ben Thomas]

Larry, I've got the balmar 91-75 dual output 75 amp.alternator with the balmar max charge regulator along with the 4" pully on my MD7A.
The same screech happens on mine as well, checking belt tension, feeling for overheating, etc. has not changed anything. the sound is short lived after regulator has ramped up to full charge, goes on for maybe 2-3 minutes then subsides. annoying and makes me uneasy. Keep us posted on what you discover.
How have you connected your refig. batterys to orgingal house bank? and to charging system. I just added two more group 31s to house bank mounted between holding tank and small bulkhead in v berth.(cd30)(massive battery cables)to my existing two group 31s. I've set it up as one house bank with four batterys parallell. This may not be the best way.
as it seems to ramp into heavy charge for 5 minutes or so then back down. even after only a few amps have been drawn from bank. Odd. I monitor via link 10 on house bank, starter battery charges after house, via the dual output. Ben



btlandscapers@imagina.com

[Ken Cave]

I have a CD28 with a Volvo MD7A, and have just switched to a Motorola 65 amp (I think) alternator with the regulator built on top of the alternator. Took about an hour to install-and had to install a kill switch so I can keep the engine running when starting and trying to get out of my slip.

Seems that everytime I put it in idle and change from reverse to foward, it would stall. Now I am able to get out of the slip-out of the marina, then turn on the alternator manually after the engine warms up! Once you have activated the field however, the kill switch will not turn it off. But, after the load on the alternator has diminished-I have not had any problems in getting back into my slip.

I also have a bank of five batteries that the former owner installed to run all the goodies, and use a Link 20 to monitor the batteries.

Have used this new alternator for about two months-so far no problems!

Ken Cave



bcave@whidbey.net

[John R.]

Greetings Everyone,

I am winding up the installation of a Balmar 80 amp, externally regulated alternator with 4in. Balmar 'Special Volvo' pulley, and wanted to tell you about the experience so far.
First of all, the installation is taking place in a 1983 CD30 with the Volvo MD7B workhorse. Second of all, when estimating the time required (and effort it turns out) for completion of this work, multiply by Pi (3.1416...), at least. Finally, you will need a trusty side-kick to help, as it is definitely a two person job..if for no other reason than for company ;^).

My first attempt, partially successful, was with the Balmar 91-75. This is a small frame 75 amp alternator, fed by a single 3/8 or 1/2 in. belt. This alternator has a maximum rpm of 10,000 rpm..remember this little number for a bit later.
We spent 4 hours removing old alt., retaining all screws, nuts, washers and belt, retrieving from the bilge dropped socket and 1 nut, driving to the hardware store (retrieval did not work), and installing the alternators and cleaning up. We spent another 2 hours mounting and routing the Balmar ARS4 3-stage regulator.

Started the engine, and ramped up to 1500 rpm, and monitored the ARS4's led indicators for proper cycling thru the normal menu of status points. All reports well. The LINK 2000 is monitoring the on-purpose 20% discharged house bank. There is a 45-60 sec. wait for the regulator to turn on the field current, allowing the engine to get up to speed, oil the bearings, and settle out a bit before it ramps the field current up to full output for the discharge you have. Mine went from a discharge of 1.9 Amps to a charge of 31 amps slowly, over 20 seconds or so. The engine definitely feels the 2 or so hp being drawn from it, as the tone deepens, and it feels like it is under load a bit...not too much, but noticeable.

Then I begin to hear a medium pitched whine that rises/falls as I change rpm up and down. Loose belt? Shut it down, and hop down for a check of the belt.
The alt. tensioning arrangement that I used is not the best, but all that I could figure out without having a tension arm made for the installation. I used the existing tension arm as well as one bought from Balmar, with the two attached end for end with two 5/16 in. machine screws and lock/flat washers and nylock nut. This places the arch of the tension bar at the right place for the alternator to contact it perfectly.

Oh yeah, alignment of the alternator was a real fun time. It IS NOT a direct drop in. The two inch foot model will be too big, so get the one inch foot model, and use shims (provided with the alternator)to take up 7/8 inch in the lower foot attachment point.

Back at the ranch..
I dropped down in the engine compartment to see if the belt was tight, and it was very tight. So we dug out the tools and tightened it even more..now bar tight, and far beyond what I know automotive alternators require. But Balmar has instructed me to use a 12 in wrench and try to turn the alternator's shaft against the engine (dead of course). If it can be moved, retighten it. So now I put enough pressure on the belt to actually stretch it a bit, and then we try the test over again. Nope, she still starts a higher pitched screeching that really sounds like dry bearings more than a belt.

Talked with Balmar, and they think it's a belt problem, but admit that bearing problems would sound the same way. So they sent me a new alternator, but better. It's a 71-80, an 80 amp high RPM alternator made for the Argentina market, due to their use of higher rpm engines (according to Balmar). This alt has two fans inside that cool the alternator better, allowing a maximum rpm of 14,000. This will fit the rpm range of the engine better.

The issue of rpm and heat turned up while talking with Blamar. We worked out the rpm at the alternator, which is a ratio of the flywheel diameter:alternator pulley diameter. I had ordered the alternator with the special Volvo 4 in. pulley (it's machined..and balanced, as these rpm's are too high for a stamped alt.)
Turns out that the rpm was as high as 10,000. The alt. was very warm to the touch.

So this weekend..weekend three of this episode, I'll be trying a looser tension first, then if that still results in the bearing sound, we'll replace the alt. with the new one just delivered.

Have to admit that it is fun watching that battery fill up 2-3x faster than with the old automtive alt. though (we did use the alt. at non-noisemaking rpm's for last weekend). [fun?! -watching a battery charge? jeesh, I've got to get a life..]

I'll write more when this is resolved.

Cheers!

Larry DeMers
DeLaMer
Cape Dory 30

Larry,
I sent you an e-mail on this matter (don't know if you received it) pointing out some areas you might want to double check such as alignment, especially that the alignment doesn't change when the engine is running. The belt fit in the alternator pulley sheave, should fit flush with backside of belt and with full contact on both belt sides showing no signs of glazing. A heavy discharge state will cause a deep whine during charging. Try a notched back belt. I would not run the belt "bar tight", you will risk the bearings. That tightness should not be necessary. Double check your battery bank state of charge with a VOM indepenent of any onboard volt meter / ammeter before starting. You may be discharged. You should have a shunted ammeter installed so you can monitor the output of the alternator. If you hear a whine and you are concerned just look at the ammeter and read the charge amps. If it's pumping out a lot of amps you will get a deep whine. If it's a high pitched whine then I'd have the bearings inspected as long as everything else like alignment checks out okay.

[Larry DeMers]

Ben,

Thanks for responding. I have -or had the 91-75 single output alt. There is a definite bearing problem with this alternator, discovered 5 hours ago now. Balmar stood up to their product without any coaxing, and upgraded my replacement alternator to the 71-80, an 80 amp high rpm/temp alternator built for Argentina I believe. It has the same exterior footprint, but incorporates twin fans inside the case, and a max. rpm of 14,000 rpm. I put the two alts side by side, and spun the pulley on each. The old 91-75 was 10x louder than the new one. Every bearing surface could be heard and felt as the shaft turned. Additionally, this was suposed to be a new alternator, but the end bearing cap is rusted and discolored somewhat. So this may have been a return/repair/rechecked unit..or maybe not. Point is, they took it back with an apology. Good folks.

I installed this new guy a few hours ago, but need a shorter belt, and as John R. suggests, make it a cogged belt. I will also seek out a high speed, steel cored version of this as long as we are getting rather rare here..and see what pops up.

Your sounds are similar to what I heard also. Mine were rpm sensitive under 15-20Amp load, and almost rpm universal at a load of 38amps charging current total. Today however, the belt started smoking and stinkning up the place, so I had to turn off the ignition switch, killing the field current, and the alt. output. It took a full 30 minutes before it stopped stinking. It appears that the bearings were seizing up and loading the alt down. My alt also made these sounds at all rpms..from 250 up thru 2300 or so. But at various harmonic points in that range. Wierd problems. You might try using a belt dressing to eliminate belt slippage as the cause of the noises. I did this yesterday, but it did not effect the sound at all. So it pointed to bearings. Try that test and maybe the fix is a simple belt upgrade like I am going to do.

Cheers!

Larry

Larry, I've got the balmar 91-75 dual output 75 amp.alternator with the balmar max charge regulator along with the 4" pully on my MD7A.
The same screech happens on mine as well, checking belt tension, feeling for overheating, etc. has not changed anything. the sound is short lived after regulator has ramped up to full charge, goes on for maybe 2-3 minutes then subsides. annoying and makes me uneasy. Keep us posted on what you discover.
How have you connected your refig. batterys to orgingal house bank? and to charging system. I just added two more group 31s to house bank mounted between holding tank and small bulkhead in v berth.(cd30)(massive battery cables)to my existing two group 31s. I've set it up as one house bank with four batterys parallell. This may not be the best way.
as it seems to ramp into heavy charge for 5 minutes or so then back down. even after only a few amps have been drawn from bank. Odd. I monitor via link 10 on house bank, starter battery charges after house, via the dual output. Ben

demers@sgi.com

[Larry DeMers]

Hi John,

Thanks for the ideas and recomendations. I will take these one at a time for clarity;

I sent you an e-mail on this matter (don't know if you received it)

Not yet, but will be back at work Tuesday, and read it then..thanks!

....pointing out some areas you might want to double check such as alignment, especially that the alignment doesn't change when the engine is running. The belt fit in the alternator pulley sheave, should fit flush with backside of belt and with full contact on both belt sides showing no signs of glazing.

Good points on what to look for. The Balmar alternator pulley was machined by them..it's 4in. in diam. and appears to be well done. It is made to take either 3/8 or 1/2 in. belts, and there are two sets of clearances machined in to the sheave itself. SO the 3/8 belt I am using goes past the sheave surface a little bit. I inspected the belt when I removed it this afternoon, as it was new to this alternator. It was not scuffed or worn or glazed, and there was no raggedness to the edge, idicating alignment troubles.

I took some pains to assure the alignment was the same as the old alternator, as far as a side by side comparison with a steel ruler and unlimited patience (it seemed) from my wife Jan, who wanted to get out sailing instead of fooling around with spacers and grinding them etc.
It seems to be a good alignment... and no black rubber dust from the belt wearing away.

A heavy discharge state will cause a deep whine during charging. Try a notched back belt. I would not run the belt "bar tight", you will risk the bearings. That tightness should not be necessary.

John, is there an industrial version of the notched belt with a tougher core.. lower stretch factor? There is with the V belt, which is what snowblowers and other high torque applications use. These I used once were grey colored. That would be what I should shoot for I guess.

Double check your battery bank state of charge with a VOM indepenent of any onboard volt meter / ammeter before starting. You may be discharged.

Last year I rewired and installed a Heart INterface system. I have the LINK 2000 and was monitoring the bank which had 28aH depletion on a 125ah bank, 50% of which is useable. So I figure that at about 45% discharged. This was intentional, as a test of the alternator.


You should have a shunted ammeter installed so you can monitor the output of the alternator.

You are absolutely right. I have 3 actually, one for each of three banks. The alternator charge rate is the sum of the three readings (two are read on the Link 2000 and the engine bank is read on the Link 10). A separate buss to read the total current is a good idea however, and one I am sort of liking ;^).

If you hear a whine and you are concerned just look at the ammeter and read the charge amps. If it's pumping out a lot of amps you will get a deep whine. If it's a high pitched whine then I'd have the bearings inspected as long as everything else like alignment checks out okay.

Yup, this is what I did this weekend. Today, I removed the alternator, and installed an upgrade that Balmar sent to replace this one with. Before installing them, I compared them side to side, and spun each rotor. The old Balmar sounded 10x louder than the new balmar, and rougher too..definite bearing sounds (I was pretty sure it would be too, as I used some belt dressing to eliminate slippage as a cause for the noise).

The shafts slowed down prety much the same however, so there was no additional drag on the shaft when the bearings were cool. Hot is another thing entirely. The old alt got so hot that I could not touch it..into a 45% depleted bank, and putting out around 30 Amps..not overly much for this 75 amp unit...
So I am going on the hypotheses that there is a dry bearing, or damaged bearing that got hot and caused a friction load on the belt in addition to the outputs load, as we did charge while this was happening. Balmar will do a failure analysis on it, and figure it out.

So I am going to hunt for a notched 3/8 belt made for high speed/high torque applications. I suppose I will need a second mortgage to afford this, but maybe not..;^)

Thanks for the good ideas..

Cheers!

Larry ~~getting ready for 3 weeks away from shore is a little like getting 6 kids ready for vacation..so many details, so many thoughts, so many plans to implement and stuff to forget!!~~~~~



demers@sgi.com

[John R.]

Larry,

I don't think it necessary that you go to the trouble of seeking out an industrial type belt. I've always used standard automotive type belts on installations and they hold up just fine as long as the tension and alignment are correct and the pulleys are a match for the belt profile.

It is interesting that Balmar machined a special pulley. Usually I've been able to locate appropriate pulleys from industrial alternator/starter service shops. Is there a specific reason why they sold you a stepped pulley or is it because that's what they happened to have?

With a 45% discharge as you state the condition was you will pick up some "deep" whine from the alternator if you get near 50 amp charge range (give or take). Initially that alternator should show a sizable charge when the engine is first started and then gradually taper back to less then ten amps. Try to install an expanded scale ammeter to monitor it's performance. Hook it up right after the output before any other components. A good place for the shunt on the 30 w/Volvo is on the starboard side of the engine compartment very close to the alternator. Should only require about a 10" wire connection from the alternator stud to the shunt. Make sure it's long enough to compensate for engine movement. Sounds like you have a fairly complicated monitoring system to begin with using two different Link systems.
It is very important that you read the entire current output from the alternator before any Link involvement.

Sounds like they originally shipped you a defective returned unit (especially considering the rusted end cap), no surprise in this day and age. They have always been good about resolving consumer matters and that's why you are getting the service you are receiving.

Keep in mind these alternators do run warm and need plenty of good ventilation. It is a good idea to run a small 3" blower with duct hose to the back side (intake) of the alternator to help it cool. Try to run the intake to the blower somewhere back under the cockpit near the stern where it will be a little cooler air. The 30 has a small engine compartment and it gets very warm in there and it is not a good enviroment for the high output alternators, same goes for the expensive regulators (best to mount them out of the engine compartment). Heat is the enemy of an alternator.

Good luck Larry.

Hi John,

Thanks for the ideas and recomendations. I will take these one at a time for clarity;

I sent you an e-mail on this matter (don't know if you received it)

Not yet, but will be back at work Tuesday, and read it then..thanks!

....pointing out some areas you might want to double check such as alignment, especially that the alignment doesn't change when the engine is running. The belt fit in the alternator pulley sheave, should fit flush with backside of belt and with full contact on both belt sides showing no signs of glazing.

Good points on what to look for. The Balmar alternator pulley was machined by them..it's 4in. in diam. and appears to be well done. It is made to take either 3/8 or 1/2 in. belts, and there are two sets of clearances machined in to the sheave itself. SO the 3/8 belt I am using goes past the sheave surface a little bit. I inspected the belt when I removed it this afternoon, as it was new to this alternator. It was not scuffed or worn or glazed, and there was no raggedness to the edge, idicating alignment troubles.

I took some pains to assure the alignment was the same as the old alternator, as far as a side by side comparison with a steel ruler and unlimited patience (it seemed) from my wife Jan, who wanted to get out sailing instead of fooling around with spacers and grinding them etc.
It seems to be a good alignment... and no black rubber dust from the belt wearing away.

A heavy discharge state will cause a deep whine during charging. Try a notched back belt. I would not run the belt "bar tight", you will risk the bearings. That tightness should not be necessary.

John, is there an industrial version of the notched belt with a tougher core.. lower stretch factor? There is with the V belt, which is what snowblowers and other high torque applications use. These I used once were grey colored. That would be what I should shoot for I guess.

Double check your battery bank state of charge with a VOM indepenent of any onboard volt meter / ammeter before starting. You may be discharged.

Last year I rewired and installed a Heart INterface system. I have the LINK 2000 and was monitoring the bank which had 28aH depletion on a 125ah bank, 50% of which is useable. So I figure that at about 45% discharged. This was intentional, as a test of the alternator.


You should have a shunted ammeter installed so you can monitor the output of the alternator.

You are absolutely right. I have 3 actually, one for each of three banks. The alternator charge rate is the sum of the three readings (two are read on the Link 2000 and the engine bank is read on the Link 10). A separate buss to read the total current is a good idea however, and one I am sort of liking ;^).

If you hear a whine and you are concerned just look at the ammeter and read the charge amps. If it's pumping out a lot of amps you will get a deep whine. If it's a high pitched whine then I'd have the bearings inspected as long as everything else like alignment checks out okay.

Yup, this is what I did this weekend. Today, I removed the alternator, and installed an upgrade that Balmar sent to replace this one with. Before installing them, I compared them side to side, and spun each rotor. The old Balmar sounded 10x louder than the new balmar, and rougher too..definite bearing sounds (I was pretty sure it would be too, as I used some belt dressing to eliminate slippage as a cause for the noise).

The shafts slowed down prety much the same however, so there was no additional drag on the shaft when the bearings were cool. Hot is another thing entirely. The old alt got so hot that I could not touch it..into a 45% depleted bank, and putting out around 30 Amps..not overly much for this 75 amp unit...
So I am going on the hypotheses that there is a dry bearing, or damaged bearing that got hot and caused a friction load on the belt in addition to the outputs load, as we did charge while this was happening. Balmar will do a failure analysis on it, and figure it out.

So I am going to hunt for a notched 3/8 belt made for high speed/high torque applications. I suppose I will need a second mortgage to afford this, but maybe not..;^)

Thanks for the good ideas..

Cheers!

Larry ~~getting ready for 3 weeks away from shore is a little like getting 6 kids ready for vacation..so many details, so many thoughts, so many plans to implement and stuff to forget!!~~~~~

[Mark Yashinsky]

Prior to this sailing season, threw in a Balmar 90-100-D and the MC-612 regulator into Goldsmith's CD27. Also replaced all the primary wiring (starting circuit too) and went up on wire size. The engine seems to start much better now. The 90 was a drop in for the Yanmar 2GM engine and other than a bad regulator (that Balmar quickly replaced), the only other problem was ripping out all the old hacked cable and getting the new wire to the mater switch. THIS NOT A WEEKEND PROJECT. Balmar did recommend in the instructions to use a QUALITY belt to drive the alternator. Seggestions were Goodyear and Dayco. Went w/ the Good year and is NOT bar tight and NO slippage. You can hear the load on the engine as the regulator ramps up the alternator. I too have been sitting there watching the regulator right after the engine starts and what it is doing. Sheesh.