Lagos
Member
400 domains and I still don't understand half this thread. Following for the electrical lore.
Question about grounding rack to copper pipe vs dedicated rod
dadlime said:
Fault current doesn't care about your server count.
This. People obsess over watts like it's a grounding sizing factor. It's about fault path impedance and trip time.
I have rod at home in Prague. Rented flat I use Schuko surge protector with indicator lights. Not perfect but tells me if outlet is actually wired. Most old CZ buildings: nope.
oops: 0000 [#1] SMP
petra
Member
I host for friends in Zagreb. Old building, shared water main. Bonded my rack to pipe, then neighbor's dishwasher leaked and plumber disconnected main while live. Rack went floating, UPS threw ground fault alarm.
Now I use online UPS with isolated output and worry less about building earth.
petra said:
Plumber disconnected main while live
This is the nightmare scenario. Pipe ground is only ground when pipe is continuous metallic. Any repair, any plastic insert, any meter change breaks it.
Dedicated rod or isolated system. Nothing between.
kenji3
Member OP
frankgait said:
Check if JP has similar tenant protection
Called city office. Short answer: no. Long answer: no, and they seemed confused I asked.
Electrician quote was ¥45,000 to inspect plus unknown to drill concrete. That's my server budget for the year.
conbini > datacenter snacks
What about equipotential bonding mat under rack? No earth reference but eliminates touch voltage between cases. Used in some medical IT setups.
Not code anywhere I know but better than wrong ground for low power.
Nova79 said:
Equipotential bonding mat
Now we're just inventing things. Bonding mat still needs reference eventually or it's a floating island. Charge builds.
Get real earth or accept the risk. Don't cargo-cult solutions.
I run everything on cloud now. This thread is why. $40/month and I sleep.
Nova79 said:
Equipotential bonding mat
Actually saw these at Yodobashi Akiba in the audio section. "Anti-static" not safety rated. Different thing entirely.
Back to my pipe ground: I test continuity to outlet earth pin monthly. If that fails I know something changed.
marchhopper
Member
20 years and I've seen two pipe-ground racks survive, three fail. Small sample but the fails were spectacular. One was fuel pump controller in industrial, 480V fault found path through water main to neighbor's well pump. Burned 200m of trenching.
Your 600W at 100V is less exciting until it isn't.