cupoftea
Advanced Member level 5
Hi,
We just looked at a customer product, and it was a offline Power supply, with PFC.
The mains input filter, was two common mode chokes (presumably with leakage inductance). These had 2.2uF X2 caps either side of them. Also, there are four Y caps…which are all 33nF in value.
The common mode chokes are marked up as “630uH".
How common are such large Y capacitor values? There’s going to be about 5mA of imbalance current …so not at the 27mA RCD trip level but high nonetheless.
We just looked at a customer product, and it was a offline Power supply, with PFC.
The mains input filter, was two common mode chokes (presumably with leakage inductance). These had 2.2uF X2 caps either side of them. Also, there are four Y caps…which are all 33nF in value.
The common mode chokes are marked up as “630uH".
How common are such large Y capacitor values? There’s going to be about 5mA of imbalance current …so not at the 27mA RCD trip level but high nonetheless.