Concerning Conversation With DB Electrical

[85lebaront2]

No, the inverter hasn't fussed due to low voltage. But it can?

As for the set point, I don't think it is due to too much heat. I think it is designed that way. Both of the regulators I've tried did exactly the same thing - they go to 14.3ish on startup and then gradually come back down to 13.3ish.

I'd read about this before, but here's a blurb I found here. And that 60C (140F) is easy to reach in the confines of a Bullnose engine compartment with a big block lurking about, and my regulators both seem to be following that "curve".

I'm going to go look to see if I have any documentation in the Ford pubs on alternators and regulators...

https://forum.garysgaragemahal.com/file/n120964/Regulator_Set_Point_vs_Temp.png

Thats the same with the Generators with the external regulator. My '56 Ford shop manual talks about having a temperature probe that snaps to the voltage regulator cover to measure voltage regulator temperature which you set to spec based off temperature to calibrate it as it is designed to vary voltage/amperage based off temperature to prevent boiling the water in the battery by putting too much voltage/amperage to the battery.

Maybe this will help, this is from the charging system section out of my '56 Ford shop manual and it goes into detail about temperature compensation for the voltage regulator. It also has a chart with ambient air temp and voltage output. I dont know how well it will mesh with the specs for the 3G but it might help give an idea since I doubt Ford would have moved too far off of these settings.

I would have expected with more modern alternators like the 3G that they would have maintained volage but only vary the amperage based off regulator temperature to prevent the boiling of the water in the battery. But I guess Ford couldnt get it to work just varying the amperage alone and has the voltage reduce as well. Which is a shame cause the NOS Motorcraft GR818 regulator I bought to swap to the 3G alternator I get has a voltage set point of 14.6V and I was hopeful that the voltage wouldnt drop below 13.0v since I know with my current 1G alternator when I come to an idle my H4 halogen silver star ultra headlights would dim slightly and my Dealer AC blower motor would slow down slightly. I was hopeful that I wouldnt run into this kind of issue with the 3G upgrade. Guess I will have to give it a go and see what happens.

Damn Rusty, It has been so long since I had a vehicle with a dynamo (generator) that I had forgotten about Ford's temperature compensated voltage regulators. Last car I had with one of those was my 1964 Falcon.

[Rusty_S85]

Jim - I don't have a cooling problem, but I'll speak to that on Big Blue's Transformation thread in a bit.

Bill - Thanks, but I don't want to change to a different style alternator. I'm pretty sure that there are 3G's that do what I am looking for, but we shall see.

Rusty - The regulator doesn't directly control the current. Instead it controls the voltage and the current is what it is. (I=E/R) But I wasn't aware that way back in the 50's they were varying the voltage based on temp.

I don't know if all 3G regulators have this function built in. But the two I have certainly do. Maybe yours won't?

Correct, varying the Voltage will change the current. With solenoids like used on old external regulators you would have to vary the voltage to get a current change. With solid state such as used in modern regulators I would have thought the ability to just control the current while maintaining voltage would have been a possibility. I mean now the most modern alternators uses clutches in the pulley where the computer actually reduces the alternator output to nothing once the battery is fully charged.

[Rusty_S85]

Damn Rusty, It has been so long since I had a vehicle with a dynamo (generator) that I had forgotten about Ford's temperature compensated voltage regulators. Last car I had with one of those was my 1964 Falcon.

Yep and for me for my '56 its a pain trying to find all those specific tools such as the temperature probe for the regulator. But eventually I think I will find one popping up on ebay like I found a set of 5 NOS stainless steel beauty rings after about four years.

But on the talk of the modern alternators, I know the real modern ones dont sense voltage and charge, they are excited by the computer itself to maintain voltage. Some have also gone so far to use a clutch on the alternator pulley where they will actually disconnect the alternator from the pulley once the battery is charged up.

With that kind of operation, I would have thought the 3G`s would have been varying amperage output but maintaining voltage to the regulator preset. It looks like what's been posted that the 3G still operates like the old temperature compensated voltage regulators from 50 years ago and vary the voltage to vary the amperage. Going to be fun to see how my 3G does with its soft start regulator with its 14.6 volt set point and if it actually varies like other 3G regulators or not.

[Gary Lewis]

"Unfortunately, we do not have the flow charts available for each alternator, but we do believe that our alternators are well equipped to perform at a high quality of standard and are made to last. We hope you’ll give our alternators and a try and that you’ll agree with us."

Thoughts, please?

This just sounds like the kind of meaningless canned reply I would expect from an outsourced customer service agency. It's really hard to say if this says anything about the engineering of the product. It may just mean that the customer service end of DB has gone downhill... but who knows.

In any case, I hope the product is still good - I just yesterday bought a DB alternator off amazon! lol

While we're talking about 3G conversions, I found the 3G page very useful all-in-all, except the "choosing an alternator" tab was a little confusing at times. But I was able to sort things out by reading through the various threads on the subject.

I ended up going with model AFD0028 130A with 8.25" mount spacing (which is referenced on the 3G page).

Jim - I misunderstood. And I see what you mean. Yes, I don't know that I have an alternator cooling problem. But I now see that the alternator sits directly behind the tip of the fan blades, which is where most of the air from the radiator comes through. So it is getting hit with the hot air from the radiator and that is probably what is causing the set point to come down earlier and farther than I would have expected.

Was talking to my nephew about this yesterday and he agreed with my assessment and was intrigued with my idea of creating a cover for the front of the alternator that just has enough room at the 3:00 position to let the belt in, but has a fitting for an air duct at the 9:00 position. That way the alternator could pull cool air from in front of the radiator and be shielded from the hot radiator air.

Lucas - Thanks for the input on the 3G page. You are seeing exactly what I saw when I went back to look at it - confusion. It really needs to be cleaned up and organized - especially in the "choosing an alternator" area.

And I hope your DB alternator works out good for you. Please let us know.

[ArdWrknTrk]

Jim - I misunderstood. And I see what you mean. Yes, I don't know that I have an alternator cooling problem. But I now see that the alternator sits directly behind the tip of the fan blades, which is where most of the air from the radiator comes through. So it is getting hit with the hot air from the radiator and that is probably what is causing the set point to come down earlier and farther than I would have expected.

Was talking to my nephew about this yesterday and he agreed with my assessment and was intrigued with my idea of creating a cover for the front of the alternator that just has enough room at the 3:00 position to let the belt in, but has a fitting for an air duct at the 9:00 position. That way the alternator could pull cool air from in front of the radiator and be shielded from the hot radiator air.

Lucas - Thanks for the input on the 3G page. You are seeing exactly what I saw when I went back to look at it - confusion. It really needs to be cleaned up and organized - especially in the "choosing an alternator" area.

And I hope your DB alternator works out good for you. Please let us know.

Gary, I don't know if I would try to create a cover or plenum for the alternator to run in.

Again, only theory, but I would feel the alternator needs to draw from all sides without restriction that would cause lower pressure (and therefore less density able to carry heat away)

The one certainty is that fully loaded the alternator is on the edge of it's ability to cool itself.

Perhaps a wing or panel to try and divert air coming off the fan towards the block?

Or the end of that duct acting as above without fitting closely? (an inch or more in front of the belt)

That big clutch fan not only draws huge volume through the radiator (when the clutch is heated to lockup) but it also stirs it all together, so when the AC condenser is operating it's going to be hotter than one might expect.

 

[Gary Lewis]

Gary, I don't know if I would try to create a cover or plenum for the alternator to run in.

Again, only theory, but I would feel the alternator needs to draw from all sides without restriction that would cause lower pressure (and therefore less density able to carry heat away)

The one certainty is that fully loaded the alternator is on the edge of it's ability to cool itself.

Perhaps a wing or panel to try and divert air coming off the fan towards the block?

Or the end of that duct acting as above without fitting closely? (an inch or more in front of the belt)

That big clutch fan not only draws huge volume through the radiator (when the clutch is heated to lockup) but it also stirs it all together, so when the AC condenser is operating it's going to be hotter than one might expect.

You are right, any cover would have to be fairly "loose" to ensure air can get to all of the inlets of the alternator. If it was very tight then only the inlets on the side where the "cold" air comes in would get air. But it could still have a tab that comes down between the belt runs to keep as much hot air from coming in there as is possible.

And yes, this is theory. But you are also right that a fully-loaded alternator is on the edge, so providing it with much cooler air would be a big benefit. And, as you point out, the air from the radiator and A/C system combined are HOT. Yesterday as we were testing it was only in the 90's outside, but the heat coming out of the engine compartment was blistering.

My nephew said he's recently worked on two different Porsche 911's, one of which has an air-cooled alternator and the other a liquid-cooled alternator. But even the air-cooled one is on a liquid-cooled stand so you have to drain the coolant just to remove the alternator!

Anyway, the OEMs are finding that alternator cooling is needed on the high-output units. So maybe I should supply some cool air to mine if I go to a high-output unit.

[85lebaront2]

Damn Rusty, It has been so long since I had a vehicle with a dynamo (generator) that I had forgotten about Ford's temperature compensated voltage regulators. Last car I had with one of those was my 1964 Falcon.

Yep and for me for my '56 its a pain trying to find all those specific tools such as the temperature probe for the regulator. But eventually I think I will find one popping up on ebay like I found a set of 5 NOS stainless steel beauty rings after about four years.

But on the talk of the modern alternators, I know the real modern ones dont sense voltage and charge, they are excited by the computer itself to maintain voltage. Some have also gone so far to use a clutch on the alternator pulley where they will actually disconnect the alternator from the pulley once the battery is charged up.

With that kind of operation, I would have thought the 3G`s would have been varying amperage output but maintaining voltage to the regulator preset. It looks like what's been posted that the 3G still operates like the old temperature compensated voltage regulators from 50 years ago and vary the voltage to vary the amperage. Going to be fun to see how my 3G does with its soft start regulator with its 14.6 volt set point and if it actually varies like other 3G regulators or not.

You might look for an infrared thermometer, they are pretty accurate and work well on a black target. We used them at the shipyard for all sorts of things.

[Gary Lewis]

Damn Rusty, It has been so long since I had a vehicle with a dynamo (generator) that I had forgotten about Ford's temperature compensated voltage regulators. Last car I had with one of those was my 1964 Falcon.

Yep and for me for my '56 its a pain trying to find all those specific tools such as the temperature probe for the regulator. But eventually I think I will find one popping up on ebay like I found a set of 5 NOS stainless steel beauty rings after about four years.

But on the talk of the modern alternators, I know the real modern ones dont sense voltage and charge, they are excited by the computer itself to maintain voltage. Some have also gone so far to use a clutch on the alternator pulley where they will actually disconnect the alternator from the pulley once the battery is charged up.

With that kind of operation, I would have thought the 3G`s would have been varying amperage output but maintaining voltage to the regulator preset. It looks like what's been posted that the 3G still operates like the old temperature compensated voltage regulators from 50 years ago and vary the voltage to vary the amperage. Going to be fun to see how my 3G does with its soft start regulator with its 14.6 volt set point and if it actually varies like other 3G regulators or not.

Rusty - Please post the part # and manufacturer of your regulator. I suspect that there are regulators out there that have different temp curves, so it would be interesting to compare.

 

[ArdWrknTrk]

You might look for an infrared thermometer, they are pretty accurate and work well on a black target. We used them at the shipyard for all sorts of things.

Most IR thermometers these days have emissivity settings.

I personally hate both black *and* chrome. If I have a choice I'll apply a patch of plain tan masking tape as a target.

If you want to read the air coming out the radiator or alternator (which is what we're really interested in) you're likely to use the thermocouple that came with your DVOM.

[Gary Lewis]

If you want to read the air coming out the radiator or alternator (which is what we're really interested in) you're likely to use the thermocouple that came with your DVOM.

I was just thinking the same thing. I have a thermocouple for my DVOM and could easily test. But, with the hood open and sitting still the test wouldn't be as valid. So I'd need to extend the leads and put the DVOM in the cab to see what the inlet air temp to the alternator is. But that would be easy enough.

On the other hand, if I'm running the winch I'll probably have the hood closed and effectively be sitting still. So maybe that's worst case and I could easily shut the hood to run that test. Then put the "hood" on the alternator and see how much it changes. That would prove whether the alternator can pull its own air effectively through the radiator support, short piece of hose, and the hood.