Relay contact insulation doesn't seem to be enough

Question

I'm working with an ESP32 and a 4 relay module. The problem seems to be that the insulation of contacts in the relay is not enough.

Relays close perfectly and my lights turn on, but when they open, a 20V or less voltage remains between the main contact and the normally open contact, enough to faintly turn on my lights. As you can see, my lamp is connected to the normally open contact of the relay. I've considered adding a resistor in series with the lamp to drop the voltage, no luck so far.

The datasheet corresponding to the part number:

https://pdf1.alldatasheet.com/datasheet-pdf/view/114955/ETC1/JQC-3F.html

In my case the manufacturer is BESTEP but the part number is the same, JQC-3F-05VDC-C.

Regarding the lamp, it's 5 parallel 50 watt COB LEDs. Couldn't find the datasheet.

This faint light is greatly undesired. Any clues as to how to work around this?

Answer 1

If the relays are wired to bring out the NC contact you can wire the pole of the relay contact to the LED, the NO to the supply live and the NC to supply neutral. In this way, when the relay resets back to not powering the LED lamp, it will also short out the lamp (but not in a way that is dangerous).

^{simulate this circuit – Schematic created using CircuitLab}

It's possible that if there's several metres of wiring involved in the installation, there might be enough capacitive cross-connection between otherwise isolated conductors to drive enough reactive current to glow the LEDs.

Answer 2

There is no solution. The 240V input to the unit is connected to an internal bridge rectifier, shorting the 240V wont discharge the internal capacitor.