Site Preparation Guide, Third Edition - HP Integrity cx2600

General Site Preparation Guidelines
Electrical Factors
Chapter 3
27
Wiring Connections
Expansion and contraction rates vary among different metals. Therefore, the integrity of an electrical
connection depends on the restraining force applied. Connections that are too tight compress or deform the
hardware and cause it to weaken. This usually leads to high impedance, preventing circuit breakers from
tripping when needed, or can contribute to a buildup of high frequency noise.
CAUTION Connections that are too loose or too tight can have a high impedance that causes serious
problems, such as erratic equipment operation. A high impedance connection overheats and
sometimes causes fire or high temperatures that can destroy hard-to-replace components such
as distribution panels or system bus bars.
Wiring connections must be properly torqued. Many equipment manufacturers specify the proper connection
torque values for their hardware.
Ground connections must only be made on a conductive, nonpainted surface. When equipment vibration is
present, lock washers must be used on all connections to prevent connection hardware from working loose.
Data Communications Cables
Power transformers create high-energy fields in the form of electromagnetic interference (EMI). Heavy foot
traffic can create electrostatic discharge (ESD) that can damage electronic components. Route data
communications cables away from these areas. Use shielded data communications cables that meet approved
industry standards to reduce the effects of external fields. These shielded communications cables must be
grounded at both ends.