I heard alot of good things about AC Delco and Accurate Diesel Glow Plugs, how long will each brand glow for without swelling or buring out? I need them to glow for 30 sec.

Got a question I heard the controller turns them on for 10 seconds but it should be on for 20- 30 sec, or am I wrong?
But I gopt my problem sloved switched it over to manual button just to see with the champion ones and it works, I only started it today, gonna let it rest till I get either ZD9 or Acucurate Diesel
Thanks everybody.