GROUNDING REFERENCE

How To Take Care of This Incredibly Important Variable

Needless to say, you must select the proper equipment to protect your sensitive phone/computer CPE. But that's just part of the power-protection battle. Once the proper protector has been chosen, the next step is making sure everything is grounded correctly. The following items are critical to obtaining an optimum grounding system.

• Bonding – Bond or electrically connect together at a single point all of the grounds used for protectors on communications equipment. Typical grounds used for protectors are metal water pipes, ground rods, well casings, chemical rods, etc.(Consult local building codes for options as local building codes vary) The communications equipment is typically connected to the power company’s multi-grounded neutral (MGN) system and is the best source for a single-point ground. Connect the protector (primary and secondary) and cable shield grounds to the equipment grounds (i.e. Multi-grounded neutral) with a six AWG solid copper bonding wire (see chart).

• Physical Connections – Make sure to use the recommended ground wire size and UL Listed ground wire connections (again, see chart). For ground wire over 60 feet in length, the next largest wire gauge should be installed. Use a large radius at each bend in the ground wire. DON’T coil ground wire under any circumstances. Coiled wire can act as an inductor that dramatically increases the resistance of the path to ground, jeopardizing the effectiveness of overvoltage devices.

• Check Ground System Impedance – There are numerous brands of equipment and methods for checking the integrity of a grounding system. Pick one that tests both continuity and the impedance (total resistance) with respect to a true ground. An ideal ground should have an impedance under .250 ohms.

• Cable Shields – The metal cable shield should be bonded to the protector/ ground systems on both ends of the cable.

• Unused Cable Pairs – They must be grounded on the unprotected side of the protector.

• Campus Building – Treat each building independently. Do all of these instructions in each building.

Is Grounding Important?

You bet your sweet voltage surge it is! The effectiveness of all overvoltage protectors relies on a path of least resistance for “dumping” transient voltages. The higher the resistance to ground, the higher the true activation level is for a protector (and the lower the activation level, the better).

Please don’t forget about grounding. Time spent on grounding basics may mean the difference between big downtime costs and an excellent return on your investment.