standards and guidelines for communication sites - Radio And ...

STANDARDS AND GUIDELINES FOR COMMUNICATION SITES POWER QUALITY
6.3.5 POWER QUALITY TESTING THRESHOLDS
The table below lists the recommended thresholds when testing AC power quality in most single-phase
and three-phase configurations (IEEE STD 1100-1999). The actual thresholds used should be based on
the installation requirements of the connected equipment, as the connected equipment may have more
stringent requirements. See IEEE STD 1159-R2001 for additional information.
TABLE 6-4 MINIMUM RECOMMENDED AC POWER QUALITY TESTING THRESHOLDS
Category Suggested Not-to-Exceed Thresholds
Frequency Deviation ± 0.5 Hz
Phase Voltage Testing Thresholds
High Frequency Noise Approximately 1% of the phase-neutral voltage
Voltage Sags –10% of nominal supply voltage (108 V for a 120 VAC circuit)
Voltage Swells +5% of nominal supply voltage (126 V for a 120 VAC circuit)
Transients Approximately 100 V over the nominal phase-neutral voltage
Distortion 5% Total Harmonic Distortion (THD) – the voltage distortion level at
which loads may be affected
High Frequency Noise 2-3 Vpeak
Neutral-ground Voltage Testing Thresholds
Voltage Swells 1% to 2.5% of nominal phase-neutral voltage
6.3.6 STEPS TO DEVELOPING A POWER QUALITY PLAN
Prior to deployment of electronic equipment, a power quality action plan should be established. To help
determine necessary corrective action, the equipment's operating norms should be reviewed according
to the manufacturers’ stated requirements for optimal performance. Next, a complete assessment of the
facility's current electrical environment should be conducted and compared to the requirements for the
equipment. Load requirements, grounding, bonding, isolation and protection requirements should be
considered.
To help maintain an optimal electrical environment, a power quality monitoring plan should be in place.
The power quality monitoring plan should require regular review of the performance of the site's
operating norms. This should include regular monitoring and recording of the site's power system, its
connected loads, failures and interruptions. The objective of the power quality monitoring program is to
identify problems and take corrective actions before incidental interference results in a wide area
failure.
68P81089E50-B 9/1/05 6-17