Disruptive field around 4/0 12 VDC 280 Amp cable?

[tex4judy]

Hello - am looking for the guys who know what the electrons are actually doing. Am converting an empty cargo van into a Class B RV. Running 4/0 cables from the secondary alternator (Nations 12 VDC 280 Amps) to the house battery buss bars. Batteries are Lithionics 2 X 195 Ah batteries. Also running a 10 gauge wire from a keyed ignition source to the internal battery monitoring system integral to the batteries and then up to the Balmar Voltage Regulator. If I run the 10 gauge wire in the same plastic conduit as the 4/0 gauge wire, is there a disruptive field from the larger wire that will "interrupt" the signals to the voltage regulator in the smaller wire? Any feedback will be helpful. Thanks

[avanti]

Originally Posted by tex4judy

Hello - am looking for the guys who know what the electrons are actually doing. Am converting an empty cargo van into a Class B RV. Running 4/0 cables from the secondary alternator (Nations 12 VDC 280 Amps) to the house battery buss bars. Batteries are Lithionics 2 X 195 Ah batteries. Also running a 10 gauge wire from a keyed ignition source to the internal battery monitoring system integral to the batteries and then up to the Balmar Voltage Regulator. If I run the 10 gauge wire in the same plastic conduit as the 4/0 gauge wire, is there a disruptive field from the larger wire that will "interrupt" the signals to the voltage regulator in the smaller wire? Any feedback will be helpful. Thanks

There will be a field, but I doubt that it will be "disruptive". It requires changes to the field in order to induce a current in the other wire (that is why transformers require alternating current). What exactly is the 10 gauge wire driving? Unless it is driving something that is very sensitive, I doubt that there will be an issue.

[booster]

I don't get what the keyed power source is. If you are going to the monitoring section of the lithionics, then you would be reading the wrong power source or feeding backwards. A keyed source could go to the Balmar to initiate it, but you want your coach battery to go the Balmare "sense" input and nothing else.

[tex4judy]

Avanti - it feeds the Internal Battery Monitoring system; which I am given to understand is like a float switch - as the battery fills up, it shuts off the alternator through the voltage regulator.

Booster - that was an interesting discussion. At first we were instructed to power the BMS from the battery itself. Then Adam Nations said they were using ignition keyed source and it worked better. One advantage may be that if the battery is dead.... I'm not sure it matters where the 12 VDC comes from; the key is that when the battery voltage reaches a preset level, it will shut off the ignition switch input in the voltage regulator, and that shuts off the alternator.

there is a separate device that is wired between the negative pole of the batteries and the negative bus bar - it feeds a battery monitor display that shows key information about the batteries. Maybe that's what you were describing.

[avanti]

Originally Posted by tex4judy

Avanti - it feeds the Internal Battery Monitoring system; which I am given to understand is like a float switch - as the battery fills up, it shuts off the alternator through the voltage regulator.

Booster - that was an interesting discussion. At first we were instructed to power the BMS from the battery itself. Then Adam Nations said they were using ignition keyed source and it worked better. One advantage may be that if the battery is dead.... I'm not sure it matters where the 12 VDC comes from; the key is that when the battery voltage reaches a preset level, it will shut off the ignition switch input in the voltage regulator, and that shuts off the alternator.

Which terminal on the Balmar is this line going into?
If I am following you, it sounds like it is an on/off (i.e., either 0 or 12VDC) signal coming from the BMS that turn the alternator on or off. If this is the case, then it is unlikely that any crosstalk with the high current line would be any issue.

OTOH, if it is the voltage sense line (which is analog), there may be some possibility of an issue.

there is a separate device that is wired between the negative pole of the batteries and the negative bus bar - it feeds a battery monitor display that shows key information about the batteries. Maybe that's what you were describing.

That device sounds like a shunt. That would be a VERY sensitive circuit--I would not parallel it with the high-current line. In fact, it is probably a twisted pair balanced line.

[tex4judy]

thank you - we keep learning....

[booster]

Originally Posted by tex4judy

Avanti - it feeds the Internal Battery Monitoring system; which I am given to understand is like a float switch - as the battery fills up, it shuts off the alternator through the voltage regulator.

Booster - that was an interesting discussion. At first we were instructed to power the BMS from the battery itself. Then Adam Nations said they were using ignition keyed source and it worked better. One advantage may be that if the battery is dead.... I'm not sure it matters where the 12 VDC comes from; the key is that when the battery voltage reaches a preset level, it will shut off the ignition switch input in the voltage regulator, and that shuts off the alternator.

there is a separate device that is wired between the negative pole of the batteries and the negative bus bar - it feeds a battery monitor display that shows key information about the batteries. Maybe that's what you were describing.

If you are having the BMS shut off the alternator from a keyed source, it will be seeing the chassis battery and the BMS will not be powered when the engine isn't running, which doesn't make sense. You want to turn off the alternator with voltage or current from the coach batteries, and you want the BMS to stay active so it protects the batteries. A simple toggel switch from the chassis battery can work as a dead battery recovery switch. I think they are trying to prevent the alternator from being able to run without the batteries online, which is necessary, but you don't want to give up good control to do it. Avanti will be able to tell you how his is setup to prevent the problem. We don't have the issue because we are setup parallel instead of standalone on the alternators.

I think Avanti is right that the negative line is to a shunt, and then you have two wire from it to the monitor, twisted pair. You don't want that pair around power wires, especially if they see ripple like you get from alternators or some battery chargers, so better in their own cable by themselves.

I think best to list off the connections to the Balmar, and where they come from, so we have a clearer idea of what you are dealing with.

[avanti]

If I were you, I would post a wiring diagram of your proposed setup. That would let folks critique it without guessing.

[tex4judy]

Can do that tomorrow. Will scan the diagram I submitted to Nations and Lithionics.

You guys have it right about the functions. And if the BMS is only controlling the alternator, then it doesn't need to see voltage when the engine isn't running.

The other power sources - solar and converter - have their own monitoring and control systems. The converter was programmed to these exact batteries and they were shipped together.

The Balmar VR and Nations alternator came pre-wired; except for the brown wire to the ignition control. The ignition source runs through the BMS; a route of about 20', therefore the 10 gauge wire.

Will get that diagram scanned.

[booster]

Originally Posted by tex4judy

Can do that tomorrow. Will scan the diagram I submitted to Nations and Lithionics.

You guys have it right about the functions. And if the BMS is only controlling the alternator, then it doesn't need to see voltage when the engine isn't running.

The other power sources - solar and converter - have their own monitoring and control systems. The converter was programmed to these exact batteries and they were shipped together.

The Balmar VR and Nations alternator came pre-wired; except for the brown wire to the ignition control. The ignition source runs through the BMS; a route of about 20', therefore the 10 gauge wire.

Will get that diagram scanned.

Ok, much better. The ignition wire goes through the BMS isn't a problem as long as it just goes through, meaning is connected unless the BMS shuts off the ignition output without being shut off itself. The BMS would stay powered of the coach battery and only switch the ignition to the alternator. If that is the case, it is nice that the BMS has an control to do that. The interesting part is that the ignition input to the Balmar is said to be a low power input, so wouldn't need to be 10ga by any stretch. If it was going to the +12v power to the Balmar it probably could be that big.

[tex4judy]

I took all the installation instructions and created this amateur diagram - mostly so I could have a basic picture of the system for my visually oriented brain. Also here are photos of the alternator and voltage regulator as it came pre-wired.

On the diagram - the blue wires are not accurate, see note on the diagram.

Thanks for your help guys.

[booster]

It appears that the "field control" is a switch to turn off the alternator field, or anything else, when the battery gets full which is good. The question would be if that switch should be fed from the positive buss or from a switched ignition source. The way it s shown, the alternator will be active whenever the battery is less than full, whether the motor is running or not, I think.

I am sure that they are switching the ignition input rather than the field so they don't get a voltage drop to the field from long wire runs, and both will work fine. You may want to confirm where to feed the field control switch power from, as my guess is it should be from the van switched ignition circuit.