Weekend Project - AC/DC volt/amp/watt Meters
Posted: May 14th, 2017, 1:27 pm
I've always been curious to know in realtime how many amps different loads were taking, from 12v lights and fans, to 120v microwave and a/c heating element.
But being lazy, I really didn't want to wire in any meter shunts (yet). Fortunately on eBay ($12-20) I found both AC and DC versions of volt/amp meters which use a loop sense instead. So all I had to do was disconnect a couple of wires, slide the amp sense loops on,and put the wires back. Then run some tiny wires for volts.
Unscrewing the distribution box and pulling it outward, allowed running the sense wires out and behind over to the meters location.
Since no shunts are needed, just tiny wires, my original plan was to run the wires up to the stove hood monitor and mount the meters in the lefthand blank side. But I was in a rush today and opted for closer to the power sources.
Below you can see the loops, one blue one below the main AC breaker, and the other white one around the red DC fuse panel feed wire. To the left are the meters (DC top, AC bottom) mounted into a fiberboard temporarily held up slantwise with tape over an access hole I cut out. Above is reading 13.5 DC volts, and 121 AC volts with 0.5A being used by the converter/charger. (Turning on the roof a/c heater coil jumped that to 14A !)
And here buttoned up a bit better. Will fancy it up later. Note this on a '94, where the distribution panel is below the fridge, and in front of the generator box. DC usage here is also 0.5A (200mA for the gas sensor at lower left and 300mA for one roof LED lamp set -- a fan can jump that to 4A). That top DC meter alternates between volts and amps, but I'm replacing it with another $12 loop meter that has both volt & amp displays like the bottom AC meter.
Next up: installing a remote shunt meter at my single house battery, which either wired or wirelessly transmits info on battery power in/output to a remote head display unit. The price for this technology is astonishingly low: The left box is the shunt and meter electronics, with optional wireless transmission to the remote display head on the right (which only measures about 1.5 x 2.5").
It's sort of like a trimetric monitor for cheap. I will let everyone know if it works well.
But being lazy, I really didn't want to wire in any meter shunts (yet). Fortunately on eBay ($12-20) I found both AC and DC versions of volt/amp meters which use a loop sense instead. So all I had to do was disconnect a couple of wires, slide the amp sense loops on,and put the wires back. Then run some tiny wires for volts.
Unscrewing the distribution box and pulling it outward, allowed running the sense wires out and behind over to the meters location.
Since no shunts are needed, just tiny wires, my original plan was to run the wires up to the stove hood monitor and mount the meters in the lefthand blank side. But I was in a rush today and opted for closer to the power sources.
Below you can see the loops, one blue one below the main AC breaker, and the other white one around the red DC fuse panel feed wire. To the left are the meters (DC top, AC bottom) mounted into a fiberboard temporarily held up slantwise with tape over an access hole I cut out. Above is reading 13.5 DC volts, and 121 AC volts with 0.5A being used by the converter/charger. (Turning on the roof a/c heater coil jumped that to 14A !)
And here buttoned up a bit better. Will fancy it up later. Note this on a '94, where the distribution panel is below the fridge, and in front of the generator box. DC usage here is also 0.5A (200mA for the gas sensor at lower left and 300mA for one roof LED lamp set -- a fan can jump that to 4A). That top DC meter alternates between volts and amps, but I'm replacing it with another $12 loop meter that has both volt & amp displays like the bottom AC meter.
Next up: installing a remote shunt meter at my single house battery, which either wired or wirelessly transmits info on battery power in/output to a remote head display unit. The price for this technology is astonishingly low: The left box is the shunt and meter electronics, with optional wireless transmission to the remote display head on the right (which only measures about 1.5 x 2.5").
It's sort of like a trimetric monitor for cheap. I will let everyone know if it works well.