0
\$\begingroup\$

Magnetrons can have a variety of failure modes, I'm trying to come up with a better test besides applying high voltage in a system and blowing fuses, or blindly swapping it out for a new one when an industrial oven detects over current / blows line fuses (480V 3Ph system, fuses are not cheap, changing Magnetrons is not easy).

When performed by a trained individual with appropriate safety measures in place, would a Megohm meter (say 5kv) be useful to help determine if a Magnetron is going to arc internally due to damage when it has a similar anode voltage rating to the Megohm meter?

This test would be performed after verifying the following:

  1. The filament has continuity.
  2. There is not continuity between the HV terminals and case/ground.
  3. There is no apparent thermal damage or antenna damage.
\$\endgroup\$
5
  • \$\begingroup\$ You mean a "Megger" type insulation test meter? \$\endgroup\$ May 15 at 17:48
  • \$\begingroup\$ I think maybe. I can imagine arcing that happens only with the filament on and/or with reflected power. Disclaimer, I haven't used magnetrons. Haven't seen a 5 kV megohm meter but I would treat one with considerable respect. \$\endgroup\$
    – Fred
    May 16 at 0:41
  • \$\begingroup\$ Ultimately, a megger shows how insulation changes over time, so it's more a regular maintenance tool than a genetal fault detection tool. One measurement is meaningless. It depends on how the arc is formed. \$\endgroup\$ May 16 at 20:26
  • \$\begingroup\$ Megger is a manufacturer of test instruments. The eponymous instrument is merely a high voltage low current ohmmeter. Changes over time is not intrinsic to the resistance measurement. You can quite easily measure insulation performance with it. \$\endgroup\$
    – MrGerber
    May 24 at 11:04
  • \$\begingroup\$ @Fred At the time of writing, Megger has insulation resistance testers in their lineup with measurement voltage at least up to 15kV \$\endgroup\$
    – MrGerber
    May 24 at 11:07

0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.