All trimmers should take an EHAP course, but, like anything some are good and some not worth doing. Electrical Hazard Awareness Program should, at least, show you the hazards associated with energized power lines and how to recognize them, as well as stay away from them.
Biggest problem we have here in Pgh with non- qualified trimmers (when they have an accident) is their breaking the 10 foot rule- and yes, it is a rule. You may not get closer that 10 foot to any energized lines without certification. If you do not know that already you need to get some training- too many people die every year from contact. Last year at the TCIA expo Dr Ball reported that the most common cause of electrocution in a tree was BACKING INTO THE PHASE!
Most of the time someone is 15 feet away from a wire they do not know the voltage of- and they lose control of a 20 foot limb. Direct or indirect the result is the same.
There is absolutely no substitute for good training and line clearance is very different from residential trimming. Not dissing anyone, I started out with Davey Tree in residential years ago, but they are very different.
I’ll repeat, all trimmers should take an EHAP course. Contact me and I can give you some more info or join the TCIA- they have some good training- but they cannot certify for LCTT (line clearance tree trimming).