29.4.1.3 The Solution
The solution in this case was simple—replace the failed connector.
29.4.1.4 Conclusions
Over time, the neutral connector had become loose. This loose connection caused heating, which in turn
caused the threads on the connector to become worn, and the connector failed. After replacing the
connector in the meter base, the flickering light phenomena disappeared.
On systems of this type, if a voltage rise occurs when loads are energized, it is a good indication that
the neutral connection may be loose or missing.
References
Dugan, R.C. et al.,Electrical Power Systems Quality, McGraw-Hill, New York, 1995.
FIPS-94 Publication.
IEEE Std. 142–1991.IEEE Recommended Practice for Grounding Industrial and Commercial Power
Systems, The Institute of Electrical and Electronics Engineers, New York, New York, 1991.
IEEE Std. 1100–1999.IEEE Recommended Practice for Powering and Grounding Electronic Equipment,
The Institute of Electrical and Electronics Engineers, New York, New York, 1999.
Melhorn, Christopher J., Coping with non-linear computer loads in commercial buildings—Part I,
emf-emi control2, 5, September=October, 1995.
Melhorn, Christopher J., Coping with non-linear computer loads in commercial building—Part II,
emf-emi control2, 6, January=February, 1996.
Melhorn, Chris, Flickering Lights—A Case of Faulty Wiring,PQToday, 3, 4, August 1997.
National Electrical Code Handbook, National Fire Protection Agency, Quincy, MA, 1996 edition.
Understanding the National Electric Code, 1993 Edition, Michael Holt, Delmar Publishers, Inc., 1993.
LEG 1LEG 2I1N'112 Volts8 Volts128 Volts240 Volts++−N
−+FIGURE 29.17 The effects of a loose neutral connection in the meter base.