Blue Seas ACR Combiner Question

[rgleason]

MaineSail and others, Thanks.
I am concerned about the voltage drop on the + voltage sense wire if routed through the switch, resulting in overcharging because the regulator is seeing a lower voltage than is at the House + post.

Is there a way to compensate for this?


Wiring Diagram.

Thanks, guys, you are absolutely right about the Blue Sea SI ACR Combiner 120a #7610
I have removed the small red wire from the 24hr panel and changed the black fuse to 10a.
It must have been another combiner diagram used awhile ago. Thanks again.

[Dulcesuenos]

Originally Posted by Maine Sail

To add a service disconnect switch with an ARS-5 you just use a Blue Sea 9004e ON/OFF battery switch with AFD (alternator field disconnect).

The regulator B+, (red wire in the Ford plug) just goes through the AFD circuit on its way to the house bank and Alternator B+ goes through the switches large studs. The 9004e obviously costs more than the mSeries 6006 that you can use with the MC-614 as a service disconnect.

They do not make the mSeries battery switches with AFD wipes in them. Obviously if you are choosing which regulator to buy then the MC-614H is the best value, if you want a service disconnect, but if you already have an ARS series regulator then the 9004e switch will work as a service disconnect and not allow the reg to boot the alt into no load if a tech forgets and leaves it off....

Just a question I hope to get an answer on. If the house is getting power from solar and voltage is up enough that start and house batteries are combined, and it's wired the way you said was best with the alternator charge feeding the house bank first, is it safe to assume the only safe way to work on the alternator at that point is to disconnect either the house lead or alternator lead from the acr, in order not to have power at the acr? Is there a simpler method?

[Dulcesuenos]

Originally Posted by Dulcesuenos

Just a question I hope to get an answer on. If the house is getting power from solar and voltage is up enough that start and house batteries are combined, and it's wired the way you said was best with the alternator charge feeding the house bank first, is it safe to assume the only safe way to work on the alternator at that point is to disconnect either the house lead or alternator lead from the acr, in order not to have power at the acr? Is there a simpler method?

I apologize I meant to say not to have power at the back of the alternator

[rgleason]

Mainesail says

" regulator B+, (red wire in the Ford plug) just goes through the AFD circuit on its way to the house bank"

That's how I was thinking it gets wired, but maybe the AFD could just shut off the Reg Field circuit (Brown wire), so there would simply be no current to the alternator when the switch is off?
So it is not using the Reg Red + Sense wire, and there would be no voltage drop when the switch is turned on! It just cuts off the field current.
If so, I'll do it, its a good safety.

[john61ct]

Adjusted:
Every pos wire **coming from a battery / charge source** on the boat needs a fuse **near the source**.

[john61ct]

Originally Posted by rgleason

I am concerned about the voltage drop on the + voltage sense wire if routed through the switch, resulting in overcharging because the regulator is seeing a lower voltage than is at the House + post.

Sorry, I am missing the reco to route a V sensor through a switch?

AFAIC
Sensors go direct to bank.

Switches should be directing power to loads, not choosing charge sources.

[rgleason]

Originally Posted by Dulcesuenos

I apologize I meant to say not to have power at the back of the alternator


"is it safe to assume the only safe way to work on the alternator at that point is to disconnect either the house lead or alternator lead from the acr, in order not to have power at the acr? Is there a simpler method?"

Engine is off, so the combiner should be off. I would disconnect the HOuse battery and then test with a multimeter.
Ah but the solar is going, and has Combiner on! Then I guess I would disconnect the Alternator Lead to the pos bus, or put in the Alt Service Switch. --Good question.

[witzgall]

I would not throw it out, but perhaps keep it as a backup. You can also use small engine mode to reduce the field output of the reg by 50%, with an similar approx drop in output, depending on the alternator.


Chris

Originally Posted by smac999

throw it out and buy a mc 614 with seperate power wire and voltage sense wire. the power wire goes to the start battery, the voltage sense and alt pos feed go to the house battery. all your problems are solved.

[Maine Sail]

Originally Posted by Dulcesuenos

I apologize I meant to say not to have power at the back of the alternator

That is what an engine room mounted alternator service disconnect switch is for. The switch needs to isolate alt B+ from the house bank and not allow the regulator to boot when the switch is off.

[rgleason]

It was unclear from the BS diagram, but the text is better.

"AFD: Cut the field wire from the alternator to the voltage regulator; connect one end to F1, and the other end to F2."
See the Instructions

Why was I thinking of the Voltage Sense Wire? duh. A drop in voltage in the field wire is not so important.
Isn't the "field" wire the brown wire tickler wire going to the alternator?

This seems to be at odds with what Rod said below and what I was thinking earlier.

[Maine Sail]

Originally Posted by rgleason

MaineSail and others, Thanks.
I am concerned about the voltage drop on the + voltage sense wire if routed through the switch, resulting in overcharging because the regulator is seeing a lower voltage than is at the House + post.

Is there a way to compensate for this?

You don't have a dedicated + volt sense wire on the ARS-5. The red wire in the ARS-5 harness is the regulator power feed AND + volt sensing. Max you will see on the red wire is 2A - 7A and a Blue Sea AFD is not going to induce but a gnats hair of volt drop. The wipes in the switch for the AFD circuit are nearly identical to the wipes for the battery cable. You'd need a hell of a lot more than 7A, to cause a drop across that AFD, that has any quantifiable significance.



If you are really that concerned feed the AFD input side with the harness 14GA then bump to 10GA between the AFD out to the battery bank.

[Maine Sail]

Originally Posted by rgleason

It was unclear from the BS diagram, but the text is better.

"AFD: Cut the field wire from the alternator to the voltage regulator; connect one end to F1, and the other end to F2."
See the Instructions

Why was I thinking of the Voltage Sense Wire? duh. A drop in voltage in the field wire is not so important.
Isn't the "field" wire the brown wire tickler wire going to the alternator?

This seems to be at odds with what Rod said below and what I was thinking earlier.

Follow exactly what I described in detail a few posts above about using a 9004e...

DO NOT cut the "field" (blue wire) with the AFD or the regulator will still be powered.

You cut the RED regulator B+ power / sense wire. Brown is the ignition feed trigger and has slight delays in shutting down the regulator. Killing brown is not fast enough to protect the diodes if this switch were to ever be flipped with the alt still running. The AFD wipes break/open slightly before the battery terminal wipes do thus saving the diodes in the alternator..

An alt service disconnect switch should isolate/shut down the regulator and alternator B+. The red wire is best for this as it kills the regulator instantly and before the B+ is opened.

[rgleason]

Once again, thank you for your explanation and solution.

An alt service disconnect switch should isolate/shut down the regulator and alternator B+. The red wire is best for this as it kills the regulator instantly and before the B+ is opened.

I am thinking of "value engineering" the (2) 9004e On-Off Switches with AFD
and eliminating the Alternator Service disconnect and providing the Emergency Battery Disconnect. Is that reasonable?


Otherwise its $70 more and the Reg B+ gets cut twice in series, and there is another set of contacts for voltage drop, but if I should have both, fine.

[waterman46]

It's good that you provide so much information in the initial post!

1. If you are burning the belt, you need to tighten belt, or get a toothed belt, or use a larger pulley on your alternator. We had to do all three. Larger pulley will require recalibration of your tachometer, but worked wonders for us. But we don't use the engine solely to charge batteries, when our engine is running we are always underway, so engine RPM is usually above 2000. If all that fails, you can investigate double belts but that was not an easy option in our case.

2. Use largest gauge wire you can reasonably fit, for the charging currents. Both ground and hot.

3. Connect your voltage sensing wires to the house battery switch terminal that is running direct to house battery.

4. Wire the ACR so that the direct path is from alternator to house battery, not going through any relays. Connect reserve or starting battery to through relay of the ACR. Relay will close and supply the reserve battery with charging current as soon as the house battery has charged a bit and voltage rises. The relays do have some voltage drop even when new, but worse, with continual high current they develop contact resistance and the loss keeps increasing with age. It's better to have the relay only carrying charging current to the reserve or starting battery as that battery is smaller and won't normally be discharged to any extent, so its charging current is much smaller.

Yes there will be times when the relay will click on and off each few seconds, as you are running through the transition phase of the sensing electronics. And if you have solar panels, it can be annoying (if you don't like that sound) because they will do so without the engine running to mask the sound. Also those relays consume about one amp each, we have two of them in our system and they are using up about 20% of the available solar panel current! That's why I'm going to change to a MOSFET solid state isolator very soon.

[rgleason]

See this please: Post #5

defelsant:
My post about this was just a thought process, it did not really happen, sorry if there was any confusion, but I think all or parts of it could happpen. Has anyone else had experience with a dead house battery, when using a Battery Combiner or Relay with Regulator Voltage Sense wire and Alternator output attached to House + post?

Also MaineSail response:
Post #11
“What if” a meteorite hits you?

Seriously switch to #2/reserve, start motor, now quickly switch back to #1 while not passing through OFF... Done.