I put in several of the 17A and the 17A1. They had Automatic electric all over them. When they first came out the documentation was terrible. They had A, B, and C phones and they worked out of same 25pr or 50pr. I amp'd a lot of cables and CPC'd them Some installers would CPC them in the ceiling. The rule was all CPCs would be at the Equipment. for obvious trouble shooting reasons. I have the manuals we sold a lot of them (over a hundred) in our small area. Were they any good, they were a POS. Lightning in our area ate them up. They were labor intensive and no advantage over 10A2. Then we started to install the TIE skinney wire systems. We initially had a lot of problems with them, but that was because we were not using static straps and lightning was eating them up also until GTE got with ITW-linx and developed the secondary lightning protection and the procedure of installation.