pianotuna wrote:
Hi rgatijnetl,
Hence the need to check before you plug in.
Checking it with a meter or plug in polarity tester will tell you if the polarity is right and the voltage is OK, BUT it will not tell you if the proper wire gauge was used or if all of the wire connections are tight. If the wire gauge is too small, or the wire connections are loose, as soon as you start to draw a load, the voltage could drop or you could lose the ground or neutral. Checking with a meter also will not tell you what happens when a bunch of other coaches are connected to the same power branch, and their power load causes the voltage to drop or fluctuate, due to insufficient power availability.
Only an EMS can protect you then.