It isn't a technicality, it is a matter of location. If installing in a cabinet where there might be a couple of feet between the entrance and the equipment, I would say you only need one to still be in compliance. If you are installing in a building you should have one at the entrance to short energy to ground thee, then one close to the equipment, like in the rack, to shunt any energy that had to fast a rise time to be caught by the Primary.
Most SPD don't have both MOV and SAD so some energy can still make it past the primary but not have enough energy to couple to other circuits properly installed. Remember, the R56 has two purposes. One is to protect equipment while the other is to protect personnel. If you don't care about the later, you can skip some things. The current topic isn't one, but your choice right? On Fri, Dec 1, 2017 at 4:08 PM <ch...@wbmfg.com> wrote: > Some surges come in via other routes, most often the power line. So you > want to stop those before they hit the equipment. Makes more sense when > you have a coax surge arrestor on the outside of the building and an AC > surge suppressor on the power input of the same system. A bit redundant > when all you have is CAT5. > > *From:* Adam Moffett > *Sent:* Friday, December 1, 2017 3:04 PM > *To:* af@afmug.com > *Subject:* Re: [AFMUG] McCown Tech surge question > Seems like a technicality. > > > ------ Original Message ------ > From: ch...@wbmfg.com > To: af@afmug.com > Sent: 12/1/2017 5:02:38 PM > Subject: Re: [AFMUG] McCown Tech surge question > > > Yes and no. Yes as they will qualify to do both jobs, but you still need > two of them to be in compliance with R56. > > *From:* Adam Moffett > *Sent:* Friday, December 1, 2017 3:00 PM > *To:* af@afmug.com > *Subject:* [AFMUG] McCown Tech surge question > > This is a question from McCown: > > I've pasted in a little snip from the 2005 Motorola R56 book. > > With the "belt and suspenders" design approach you've mentioned in the > past, would it be fair to say that your products would qualify as both a > primary and secondary protection device as defined herein? > > > >
