On Mon, 10 Feb 2014 10:32:26 -0700, wrote:

...snip...
The one exception was one tech who ventured that perhaps momentarily
reversing polarity on alarm before DC drop out might work, however he
had never tried it. Does anyone have any ideas about this? Thanks, Lenny


I've always found that having ferrous metal in a DC field touching each
other is not a good idea. Add a 3 mil layer of kapton tape between the
two. the extra distance will prevent the 'residual' magnetism from having
enough strength to hold and keep the doors open. More likely difficulty
keeping them open.