Q: Are there enough changes to the 2nd Edition that I should buy it if I already have the original edition?
A: The physics of electricity haven't changed but the types of loads we're using in live event production have and are. I've reorganized the book and make fairly substantial changes in the 2nd Edition, but I'll let you decide whether or not to update your library. Here are the main changes from the original edition to the 2nd Edition.
1. Added a chapter on terminology—The vocabulary of the electrician is very important and miscommunication can lead to catastrophe. I was just reading an article in Electrical Contractor & Maintenance magazine about an electrician who accidentally cut a live 13.8kV feeder cable. Miraculously, he walked away from it but that should never have happened. Good communication is key to safety.
2. Loads and Sources—I reorganized and rewrote most of the book and in particular chapters 5 (types of loads) and 7 (types of sources). I added a lot of information about portable power generators—how they work, operating procedures, grounding, etc.—and battery power, since batteries are becoming more important in live event production.
3. Electrical Safety—I added more information about electrical safety including more detail about the proper personal protective equipment (PPE) to wear for particular tasks.
4. Grounding and Earthing—Grounding and earthing is an area that is a bit controversial, and grounding/earthing practices are still evolving. I've included more practical information on this subject.
5. LEDs and PWM—One of the biggest changes in live event production is the proliferation of LEDs, which are very different electrical loads than incandescent lamps. I've included more information about how LEDs and other non-linear loads affect power distribution and what to do about them.
6. Graphics—The live event production community is a very visual group, so I've tried to include more illustrations and pictures to better explain some of these concepts and ideas.
7. Practice problems—The best way to better understand electrical systems is to read and discuss the concepts and then work out some problems. Almost every chapter has new practice problems and I've tried to word them in a way that makes sense to electricians and technicians in our industry. The answers are at the end of the book
8. General tone—I've tried to change the general tone of the book by using a bit more conversational style of writing in order to make it more user friendly.
9. Math and equations—I've moved most of the ugly math to the appendices in the back of the book to help it flow better and in order to not slow down the casual reader. The information is still there but it's not in the main text unless it's integral to understanding the topic at hand. For example, the text no longer contains the equation for solving the RMS value of a sine wave. You don't really need to know that unless you're even more nerdy than me.
10. Worldwide voltages—I've added an appendix at the back of the book showing the voltage connection schemes and voltage levels for different countries around the world.