info req on polarity checks
resistance 2 earth
info on sites welcome
2007-04-23 10:12:18 · 5 answers · asked by ? 4 in Science & Mathematics ➔ Engineering
Most appliances are connected to the supply via fused spurs or plugs, it is the polarity of these that you should be checking and since most plugs are labelled and wires colour coded I don't see a problem.
A final check would be to measure the voltage to earth from live and neutral (live:240 V; neutral 0 V)
2007-04-24 10:20:15 · answer #1 · answered by Anonymous · 0⤊ 0⤋
To correctly perform a polarity check, you need to identify a good earth ground. Often a water pipe is handy and this is good thing to use. (However, be sure that you do not inadvertently connect to a plastic pipe..)
Measure the voltage between what you think is the hot (line) terminal and your ground. You should measure the full line voltage.
Measure the voltage between what you think is the neutral terminal and ground. You should measure near zero - possibly as much as a few tenths of a volt but it should never be more than that.
Measure the voltage between what you think is the earth ground terminal and your water pipe. This should be zero.
If you measure zero volts between your earth ground terminal and the water pipe, you can attempt to measure the resistance between them. It should be no more than a couple of ohms, preferably less than 1 ohm.
Do not attempt to measure resistance of the hot side. If the power is connected, you will likely blow out your meter. If the power is not connected, it will not prove anything anyway.
If there is no water pipe, you can use the earth ground of an outlet that you know is correctly wired.
If you are in North America and you are working with an appliance that plugs into a 120V outlet, the U-shaped hole on the outlet, corresponding to the round pin, is the earth ground. The longer slot is the neutral. The shorter slot is the line. If you look at an outlet so that the ground is on the bottom, the neutral slot is the one on the left and the line is the one on the right. If you look at the plug with the prongs pointing toward you, obviously the relationship is reversed.
2007-04-23 16:23:23 · answer #2 · answered by AnswerMan 4 · 0⤊ 0⤋
I think u are asking about AC appliances . U have a hot side and neutral side . Turn off the washer and be sure it is disconnected. With the ohm meter measure from chassis to each side of the plug . The one that shows low Resistance to ground will be your neutral. If u are truly off the hot side should measure infinity resistance.
2007-04-23 13:32:05 · answer #3 · answered by JOHNNIE B 7 · 0⤊ 0⤋
Heater gas
2016-01-16 12:13:32 · answer #4 · answered by tim 1 · 0⤊ 0⤋
If polarity is correct your meter will read a +VE if incorrect then it will be -VE.
2007-04-23 10:17:12 · answer #5 · answered by Anonymous · 0⤊ 1⤋