Some transformers in the power supplies provide a little humming noise and that is normal. If the humming in Von Duprin PS873 power supply is loud follow these steps. Remove the load from the outp...
Since most wire transfer devices such as an EPT or electric hinges cannot provide large gauge wires, we take the small gauge wire into account when determining the overall wire size for the device....
Use #18 gauge wire up to 200 feet maximum distance from PS900 x 900-2Q power supply to the QEL exit device. The new QEL+ no longer requires the 900-2Q board but still needs a different option board...