where to put volt/amp meter in circuit
looking to install meter near WFCO. Currently, it is wired with RED & White into meter > WFCO and only reads AMPS when plugged into shore. Can someone please look at circuit diagram and tell me whic...
Forum Discussion
It seems the Chinese put the shunt between the negative terminals. A "shunt" is a short piece of wire with a small resistance so current going through it causes a small voltage across it. The rest of the ammeter is just a voltmeter to measure the small voltage. Meters with higher amp ratings will have an external shunt so only the small voltage need go to the meter through light wires. On ebay ammeters be careful to make sure it says the shunt is included or built in - often it is not. The current flowing from input minus to output minus terminals will be measured. You could cut the wire to the battery negative and insert the meter in line.
Or more practically unhook the wire from the negative battery terminal and connect it instead to the ammeter output negative. Run a new wire from the meter input negative to the negative battery terminal. I have a "battery monitor" in that same box. I broke a terminal connecting a 12 gauge wire so I recommend using 14 gauge. If the #14 wires are short and the current under 15 amps it should not overheat or cause a troublesome voltage drop. You will also need a connection from battery positive to one of the meter positive terminals, just one since the two positive terminals are just connected together in the meter box. This connection just powers the meter electronics so only a light wire is necessary.
When you charge the battery via converter, current will flow backwards through the meter. I wonder what it will do? If it can show reverse current that feature will be listed in the ad. If not hopefully nothing will happen. I think it will be okay. Current going through the shunt backwards will just put a tiny reverse voltage on the electronics of the meter display so no danger of fire anyway. No loss if it does kill a chip in the meter - it wouldn't be useful for monitoring the battery anyway.
Please post what happens and a link to the ebay item so others will know what to expect if they buy it. We work together to get value out of these bargains.
Or more practically unhook the wire from the negative battery terminal and connect it instead to the ammeter output negative. Run a new wire from the meter input negative to the negative battery terminal. I have a "battery monitor" in that same box. I broke a terminal connecting a 12 gauge wire so I recommend using 14 gauge. If the #14 wires are short and the current under 15 amps it should not overheat or cause a troublesome voltage drop. You will also need a connection from battery positive to one of the meter positive terminals, just one since the two positive terminals are just connected together in the meter box. This connection just powers the meter electronics so only a light wire is necessary.
When you charge the battery via converter, current will flow backwards through the meter. I wonder what it will do? If it can show reverse current that feature will be listed in the ad. If not hopefully nothing will happen. I think it will be okay. Current going through the shunt backwards will just put a tiny reverse voltage on the electronics of the meter display so no danger of fire anyway. No loss if it does kill a chip in the meter - it wouldn't be useful for monitoring the battery anyway.
Please post what happens and a link to the ebay item so others will know what to expect if they buy it. We work together to get value out of these bargains.
