This Electrician Training video by http://www.bin95.com is a bit of a schematics tutorial on reading schematics as they pertain to electrical timers. It gives you electrical tips on if the relay timers shown are delay on timers or delay off timers too. This is just a small, low resolution sample from DVD 2 of the 10 DVD Industrial Electrical Training Video Library. The actually DVDs have much better quality and more details. http://www.youtube.com/watch?v=m5_i-77GPgg