Using isolation class 2 power supply - I'm reading 50 volts between antenna ground and earth ground?

Thread Starter


Joined Oct 21, 2014
Hey guys,
I built a circuit using this part "IRM-20-12" from Mean Well, which I'm assuming uses some sort of a transformer inside of it:

The circuit consists of the power supply, a microcontroller, and a 2.4GhZ RF module where an antenna plugs into it.

I took an AC voltage measurement between the antenna ground and earth ground, and I am getting about 50 volts.

I want to mount the antenna in a metal enclosure, but I fear that it will short out 50 volts?
Here are what the antennas look like:

What is the proper solution here? It seems to use either a plastic enclosure, or to isolate the antenna from the enclosure somehow? The case must be metal by the way. What if someone unscrews the antenna, could they get shocked?

Is there something that I am missing? Thanks and any help is greatly appreciated!


Joined Jul 18, 2013
Generally those readings will not support any kind of significant current, if you are using a electronic volt meter, the high impedance reading can be misleading.


Joined Jun 4, 2014
It is the sort of leakage, mostly capacitive I believe, that you get with switch mode supplies. It is a very low current and no harm will come to anything if you short it out. As your voltmeter is high resistance the small current generates a significant voltage.