Grounding(electrical)

[jick.cejoco]

Hi peeps,

i recently got schooled on how to properly ground our equipment here in the office. Basically a contractor installed a ground wire on our equipment racks(with pcs, switches, etc). They used a VOM to check for grounding, and found that some equipment were OK, some were not. They suggested that we run ground wires to each equipment to be sure.

Some questions:

1. Sabi nung isang electrician, we just need to ground one server/switch, then OK na daw. But nagaground pa rin when we tested the other equipment. Need ba talaga maglagay ng ground wire per equipment?

2. Do i need metal to metal contact, i.e. metal covering to ground wire? i'm getting conflicting answers, sabi ng iba need pang iscrape yung paint para me contact, sabi naman ng iba hindi na kelangan.

3. The contractor mentioned that they somehow connected the ground wire to sprinkler pipes, in addition to attaching it to the building/floor's earth ground, for additional safety daw. Tama ba yung ganito?

4. We have a few servers with aluminum casing, no paint or coating. Can we ground it by attaching the ground wire directly onto the casing?


tia

the contractor is partially right. grounding is necessary. but to check for proper grounding, you check using an ohm meter.
grounding is used to dissipate unwanted or stray or eddy voltages. airplanes use those little static dissipators (usually found on the trailing edges of the wings) to get rid of electrical charges (both static and from lightning strikes) to the surrounding air and further grounded by personnel once it is on the ground. in germany, even the low lying metal buildings are grounded to reduce corrosion and to dissipate lightning voltages. the purpose is twofold, one, to reduce the hazard of electrical shock and fire, the other to get rid of unwanted electrical charges that might interfere with sensitive electrical or electronic circuits. the potential difference in electrical charges between an object and ground makes the voltage ready to discharge