TELECOM POSITIVE GROUNDING
TELECOM POSITIVE GROUNDING
(OP)
WHAT IS THE REASON THE TELECOM INDUSTRY USES NEGATIVE 48V, POSITIVE GROUND?
When was the last time you drove down the highway without seeing a commercial truck hauling goods?
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TELECOM POSITIVE GROUNDING
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RE: TELECOM POSITIVE GROUNDING
Search http://mirror.lcs.mit.edu/telecom-archives/ for discsussion.
RE: TELECOM POSITIVE GROUNDING
I was interested to see what it had to say on this. No luck with the search engine, but the FAQ page linked to off the home page had the answer.
RE: TELECOM POSITIVE GROUNDING
peebee, although it has nothing to do directly with grounding, polarity in protective-relay trip circuits seems to have a slightly conflicting rationale.
From http://www.pes-psrc.org/k/rlytrckt.zip… In order to minimize the effect of corrosion, relay coils should be permanently connected to the negative bus in dc control schemes. If moisture is present and the coil is directly connected to the positive bus, electrolytic corrosion may occur, causing the coil to become open-circuited and preventing the relay from operating.
RE: TELECOM POSITIVE GROUNDING
You've made my head hurt once again busbar.
RE: TELECOM POSITIVE GROUNDING
peebee — if severe pain persists, combined shots of intramuscular Stadol and Toradol can be quite effective.