Round numbers like 1 million have the feel of some one trying to make a good stab at an order of magnitude.
If the limit was 21.679 there may be some sums behind it
The values for bleed resistors are based on a sum, and it is that we get must get down from peak voltage to below 50V (a safe voltage on the pins of a plug perhaps) within 5 seconds of disconnection - so if you pull the plug out from kit with a filter inside, you do not get a bite off the pins half an hour later when you want to plug it in again.
Longer bleed times are permitted on things that are enclosed and hard wired.
Even then we calculate and unless it is going to run really hot, fit half that value for a bit of margin.
Round numbers like 1 million have the feel of some one trying to make a good stab at an order of magnitude.
If the limit was 21.679 there may be some sums behind it
The values for bleed resistors are based on a sum, and it is that we get must get down from peak voltage to below 50V (a safe voltage on the pins of a plug perhaps) within 5 seconds of disconnection - so if you pull the plug out from kit with a filter inside, you do not get a bite off the pins half an hour later when you want to plug it in again.
Longer bleed times are permitted on things that are enclosed and hard wired.
Even then we calculate and unless it is going to run really hot, fit half that value for a bit of margin.
