To test current, you need a load, either the thing you intend to power, or an equivalent dummy load. 400v @ 16A is going to need one hell of a big resistor. To measure current, hook up the load and then measure voltage. I = E/R. Optional extra credit: observe the waveform under load to make sure that it's sufficiently sinusoidal. Bill Dudley Retired EE On Jul 8, 2017 6:38 AM, "Ben Greenfield via vcf-midatlantic" < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote: ---------- Forwarded message ---------- From: Ben Greenfield <ben@cogs.com> To: vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> Cc: Bcc: Date: Sat, 8 Jul 2017 08:35:57 -0400 Subject: Off topic-testing 3 phase power Hey All, I find myself needing to verify that an outlet is supplying 16 amps at 400 volts Alternating Current at 50 Hz. I have verified the voltage with a multimeter but feel I should be more thorough. I’m trying to purchase an appropriate european socket tester which is much cheaper if not as versatile as Fluke 109-104. I also have a Tektronix 2355 which I think I could measure each line on it’s own channel to measure the voltage and the phase. Is there a safe way to measure current with this oscilloscope? Thanks, Ben