I put the clamp style on my larger surge protectors. It is on a 1/4-20 brass lug.
From: Ken Hohhof Sent: Sunday, February 26, 2017 1:08 PM To: af@afmug.com Subject: Re: [AFMUG] Ground Lugs 1/4-20 and 5/8 spacing works for me, I don’t think you can satisfy everyone. I would even be OK with a single ground screw, but some people will make a reasonable case that a 2-hole lug is better, and you can still use a single hole lug if that’s all you have. The ground bars in shelters and at towers are typically going to have dual 3/8 screws and wires will be #2 or heavier, but that is overkill for what you are doing. From: Af [mailto:af-boun...@afmug.com] On Behalf Of David Milholen Sent: Sunday, February 26, 2017 9:31 AM To: af@afmug.com Subject: Re: [AFMUG] Ground Lugs Forrest, Use the motorola R56 standards for a base for all your grounding. There are a few layered standards for grounding but motorola is on top of these other standards for telcom gear. I have always tried to be a good steward of these standards when using existing sites but the Broadcaster towers built pre 1990 are a big challenge. https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwj589iAiq7SAhWK5oMKHeHwCwUQFgggMAE&url=https%3A%2F%2Fsites.auburn.edu%2Fadmin%2Ffacilities%2Fspw-bid-calendar%2F11-150%2520AU%2520Regional%2520Airport-Construct%2520a%2520Self-Supporting%2520Radio%2520Tower%2FProject%2520Documents%2F1%2FMotorola_R56_2005_manual.pdf&usg=AFQjCNHlYoTBfjY-zLOUUebdvd3RLH_Cwg&sig2=gZT9-oejY-fxgK2TrdRnWQ There are 518 pages of stuff but do a search for Rack and Rack equipment grounding and you should find what you need. Dave On 2/25/2017 10:12 PM, Forrest Christian (List Account) wrote: So, I've now had two people ask me to include a ground strap point on the back of the new rack injectors. So I figured, I'd just go figure out what the standard was for the hole spacing, screw diameter, and similar, and add it to the list of things which will be modified slightly in a future batch of enclosures - shouldn't be much more expensive to get them to mask off a small section when painting and add the appropriate screw bosses.... Simple, right? Well, that was until I tried to find the standard..... In a juniper manual I discovered they have two sets of bosses.... one with 1/4-20 screws, one with M6 Screws... the 1/4-20 screws are for the US market and the M6 ones are for the European market. Ok, I get that... Metric vs US. But then the spacing is 0.625 (5/8) inches for *both* of them - not say for instance 0.625in and 15 or 16mm which would make sense. So I figured I'd look around more... Then I go over to the cisco manual. They use M4x8 screws on most stuff, sometimes something different. Spacing seems to be around 1" (freakin metric screw and english spacing). After 2-3 more vendors of total inconsistency, a word comes to mind: Cobblefuckery. Pure Cobblefuckery. WTF? I thought this was for grounding in a Telco environment, and shouldn't this be specified out the wazoo by telcordia, with all of the vendors falling over backwards to make their equipment NEBS compliant with exactly the right hole spacing for grounding? Maybe two competing standards for English vs Metric, but not as it seemed, everyone making up their own crap. Although the 5/8" spacing and 1/4" or M6 screws seemed to be slightly more common than all of the other pure randomness I was finding. So the NEBS thought lead me down the rathole of telecom standards. Eventually I find ANSI/TIA-607-B - it looks like the 5/8" spacing and the 1" spacing are both specified in ANSI/TIA-607-B for grounding busbars. The hole diameter for the 5/8 spacing holes is specified as 5/16" on the busbars, which seems to be a good match for a 1/4-20 screw. So it seems like the juniper spec of 1/4-20 on 5/16 spacing would match a lug designed for a ANSI/TIA-607-B compliant busbar. The M6 would be fine too - just a bit smaller... The spec also lists 8mm holes on 16mm spacing as a option for the exact same holes which I guess would be close enough since we're really only talking about a millimeter or so here - probably a bit more or less slop, but still close enough to work. But what about that cisco spec of 1" spacing with a M4 screw? I'm still not sure WTF they were thinking. ANSI/TIA-607 specs a 11mm diameter hole at 1" spacing. A M4 screw isn't going to work well in a 11mm hole. Cisco... go figure. At this point, my intent is to see about including two 1/4"-20 screw holes spaced at 7/16" and appropriate bare metal in a future revision of the rackinjectors. Does anyone have any reason why this isn't the right spacing and hole diameters? Or maybe even some validation that I got this right? -- Forrest Christian CEO, PacketFlux Technologies, Inc. Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602 forre...@imach.com | http://www.packetflux.com --
