what is el


EL only retracts the latchbolt or vertical rods/latches. ED retracts the latchbolt or vertical rods/ latches and the push pad of the device at the same time.
Reference The 914 Installation instructions.
 Electric latch retraction, EL, devices are only available in 24VDC.
The potted circuit breaker for the Von Duprin EL device does the switching from the 16 amp pull coil on the solenoid to the .33 amp holding coil of the solenoid.
The PS914 x 900-2RS option board doesn't have time delay. If time delay is required specify PS914 x 900-4RL. 900-4RL provides up to 75 seconds, 5 second  increment unlock time.