2 Current Sources

[lgcdmb]

I have a B&C SD-8 backup alternator, and would like to be able to monitor the current from it while in use. I've got shunts for it and the 60 amp primary alternator, but you only have one input for shunt current sensors. Can I put in a DPDT switch to let me switch to the backup when it's in use? Calibration may be an issue, but I'm thinking that I can tweak it with a resistor. Maybe there's a better idea to deal with my problem.

[dnelson]

Hi David,

I believe that you could technically do that. I would avoid adding any resistors to correct for any calibration issues. The AF-4500 has a 2nd current sensing method: Hall Effect. It is possible to use the Hall Effect to measure more than one power source with a little planning. I know that a couple of us use this method to measure the main and backup alternators/generators.

Anyways, something to ponder over.

Regards,
/\/elson

[lgcdmb]

Do you mean run both feed lines through the Hall Effect transducer? I can see how that would work for a few extra $. Thanks for the idea.

[dnelson]

Hi David,

Yup. Direction of current flow is important - there is a note on the Hall Effect sensor assembly concerting orientation to get you started and you are going to have to think that through on how it fits into your wiring scheme. You will also need to figure out what your goal is. For example: Do you just want to know what your energy sources are doing or what your battery is doing. Those kinds of things.

Good luck,
/\/elson

[Rob Hickman]

The Engine Monitor has two current inputs, one Hall and one Shunt. If you want to monitor two alternators you need to use both.