PEM replacement...

[Confused]

OK - educate me chaps. What is the rational behind a PEM replacement? As it happens, this is not a post from a"PEM sceptic" or anything, I simply have no idea what the rational is behind this tweak.

[Borgen]

Manoet had a good description of this in an earlier thread, see http://devialetchat.com/showthread.php?tid=1704

[Manoet]

kenreau/Borgen-

You're both correct in that line/neutral can probably be switched without issue. I've never been a stickler for the protocol but since I knew I was going to seek warranty reinstatement upon completion I opted to keep that aspect as OEM as possible in the event of a future power board failure, which wouldn't be the first one to short circuit here. But no one can accuse mine of going 'tango uniform' because of it or ever say "Aha...caused by inverse wiring!" I've explained previously that I'm a bit picky about my AC outlet orientations to the point of OCD. I want my 15/20A outlets to be mounted with L/N blades on top and G on bottom. I want every outlet in the house that way. Most commercial/resddential electric houses install that way. But there's no US NEMA spec or code requiring it. Same with most audio manufacturers. I want the same thing with my equipment IEC inlets when viewed from the rear of the cabinets right-side-up. The Devialet IEC was always upside-down in my mind/world. So I mounted it correctly to my preference which necessarily dictated rotating the IEC mains inlet 180 degrees from the Devialet spec and an "X" wiring pattern to keep the Line/Neutral conductors soldered to the same connections Devialet had used with their PEM on the power board. Sure it would've been easier to just leave it but then any time I needed to remove those wires I'd have to pull the ENTIRE primary PCB, PSU, all 2nd story pCBs et al just to loosen those wires from the backside of the IEC... a MAJOR project!! I simply followed factory wiring connections but utilized my preferred visual aesthetic in doing so which also allows me to remove AC Main leads from the IEC with only belly pan removal. No foul/no error.

As you can see in the below pic if I had left the IEC the way Dev installed it all provisions for tightening/loosening AC leads in the IEC would've been between the primary PCB underside and the Devialet ceiling. Impossible to get at with PCB installed! As I've installed it it can easily have its wires loosened with belly pan removal. Of course I considered making those wires an extra 3-4" long then I could just unscrew and pull the IEC outlet out a few inches but that didn't meet with my minimalist EMI/RFI design goals.

   

[kenreau]

Good to know, makes perfect sense, thank you very much!

Kenreau

[mauidan]

Manoet,
I'm surprised you didn't clean off all that solder flux on your PEM connections.

[Manoet]

No soldering flux present I assure you but moreover simply where the iron touched PCB paint while hot and circuit board was chucked in a vise and I was holding the soldering iron to the top side (pictured) with my left hand and trying to keep solder flowing while simultaneously pulling the stubborn barbed PEM female spade connectors through the board from underneath with needle nose pliars in my right hand. That's as clean as I could get the area afterwards without removing scorched paint. Sadly unavoidable in this case but no worse than a half dozen places on the OEM boards that jump to mind like this one on the PSU below. While the imperfection bothers me the connection is sound and I have no issues being human, fallible, less than perfect and providing pics that are capable of magnification showing warts and all bigger than life.