Hi, i have just had two digital panel meters delivered but they have no instructions with them. They are dual readout being volts top and amps bottom. There are two power supply leads and three test leads coming from the back. My question is how do i connect these up? I am aware that these meters can not be powered by the circuit being monitored but my uncertenty is of the three test wires. I am thinking that maybe the black is common and the other green and red are to be placed as, one paralel and one series, in irder to get both volt and amp measurment. But i have heard about shunt wires and i would like it if someone could explain this to me please and if one of the leads may infact be a shunt wire. I am in hope that my first guess of how to connect it is correct as it will save a lot of switching araingments as i already have to set up switching of the two meters to go between four seperate supplys within the same box. Please can someone let me know if i have the right idea in wiring the three test leads as i am worried about breking them. Unfortunately they do not have model numbers on them and no commercial packaging. Thanks in advance for any help you may be able to give
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Three wires into the combined two meters?
or
three wires to each meter?
If I read that first option correctly then one is Neutral and the other two are Live.
But before you connect you have to work out which do what !!!!!!
or
three wires to each meter?
If I read that first option correctly then one is Neutral and the other two are Live.
But before you connect you have to work out which do what !!!!!!
Per meter, there is red and black for the 4.5v to power the meter. the three other wires are the measure wires that are black green and red. when i read the description it says they are built in shunt meters. guess i will just have to connect them to a limited current supply and hope it does not break. Thanks guys
the "shunt" meter requires two wires to measure current.
What is the third wire?
If the third wire is to allow voltage measurement, then you have a problem of identifying what each wire does.
What is the third wire?
If the third wire is to allow voltage measurement, then you have a problem of identifying what each wire does.
If it has a built in shunt you should be able to measure the shunt resistance between just 2 of the wires which would leave the 3rd wire to be connected to the opposite rail for voltage measurements , ie the shunt connected wires will need to be connected in series with the output ( for current measuring ) .
between two wires the reding is 0.3 ohm, the rest is open circuit so i guess it will be those two.....But dose 0.3 ohm seem like an expected value for an internal shunt? If so, i got it sorted. Cheers guys : )
Yes 0.3 ohm seems about right . Just for info between which 2 colours do you measure 0.3 ohm .
PS ..of course you will need to get the polarity correct of these 2 wires ( one to source and the other to load ) for the amps reading to be +ve and not -ve , if indeed it will do -ve readings .
PS ..of course you will need to get the polarity correct of these 2 wires ( one to source and the other to load ) for the amps reading to be +ve and not -ve , if indeed it will do -ve readings .
dc 0-100v and 100mA-2A atleast i assume it would be 100mA unless its auto ranging. But for £5 i doubt it
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