Cheap ammeter for power hungry RV's

tarnold wrote:
Could you be more specific about what wires go where? Looking at the back of the unit, the wire taps from top to bottom. Understand no printed instructions, just diagram on back of unit. Also is there a problem with lengthen those short supplied leads?

I guess I don't see what's so confusing about the diagram. Two of the wires go to the current transformer (the dounut thingy), which has the wire you want the current measured passed through the center. The other two go to the hot and neutral lines to measure the voltage and power the meter. I don't think it cares about polarity one way or the other...if it does, swapping the two wires in either the current sense or the voltage sense pair will take care of things.

In most cases it would be necessary or at least advisable to lengthen the wires by splicing on some additional wire. I used "security alarm wire" which is 120V rated multiconductor cabling in fairly small gauges. I put in (and recommend) a smallish (1A) AC fuse at the hot connection since the wire is a good bit smaller than the 12 gauge wire of the circuit I used.

(The voltage sense line ought to be from a branch circuit, IMHO, and not tapped into the main line coming into the RV. If for no other reason, this ensures that the main breakers in the RV panel will turn off AC power to everything in the RV, including the meter. I put the voltage sense connection on my air conditioner circuit since I decided that's the one I care about the voltage on the most...though close to the electric panel it really doesn't matter much since there should be no significant voltage drop on any of the circuits.)