Duration of power to Kato N scale switch

[simbafish]

How long can power be applied to a KATO N Scale switch, such as 20-203, before it overheats and damages the solenoid?  I have built an electronic circuit which will momentarily change four (4) switches to the preferred "demo" position when power is first applied to the layout. Using a one shot multivibrator, I have components chosen for one second cutout, but I find this is not stable. Sometimes power is not turn off until ten seconds (I am still in the mock-up testing stage). So I would like to know how long power can be applied before there is damage to the switch solenoid. Thanks for all help.
 

[kvp]

I would say 100-200 ms. Normally one tenth of this switches the turnouts fine.