Rack rails on network equipment

Sat Sep 25 03:28:53 UTC 2021

On 9/24/21 10:58 PM, Owen DeLong via NANOG wrote:
> Meh… Turn off power supply input switch, open chassis carefully, apply high-wattage 1Ω resistor across capacitor terminals for 10 seconds.
> 

If dealing with a charged capacitor, do not use a low resistance such as a
ohm.  This is the same as using a screwdriver, and will cause a big arc.  You
want to use a 100k ohm device for a couple seconds, this will bleed it off
over 5-10 seconds.

Most (all?) power supplies will have a bleeder over any large value caps, and
will likely be shielded/encased near the input anyways.  If you let it sit for
5-10 minutes the leakage resistance will dissipate the charge in any typical
capacitor.

-- 
Bryan Fields

727-409-1194 - Voice
http://bryanfields.net