It is important to note that a person can be considered qualified with respect to certain equipment and methods, but still be unqualified in other situations.
Working with electrical power has always been a risky business, and potential hazards - including arc flash - are on the rise.
Because of the severe and often devastating consequences of arc flash incidents (which claim at least one life every workday), the NFPA is using several strategies to facilitate worker safety starting with the requirement that workers be properly qualified for the work being performed.
Test decals are an important part of any electrical maintenance program, they provide immediate indication of the last maintenance date and the overall condition of the specific devices that have been tested and maintained in the field.
This can assist employees in the assessment of the overall electrical equipment maintenance status.
The following inspections and tests should be performed before energizing newly installed low voltage wire and cable rated 600V or less.
Time-current curves are used to show the amount of time required for a circuit breaker to trip at a given overcurrent level.
Time-current curves are typically shown on a log-log plot. Figures along the horizontal axis of the curve represent the continuous current rating (In) for the circuit breaker. The figures along the vertical axis represent time in seconds.
There are many things can happen to a circuit breaker on its journey from the factory to facility, and while they are always tested by a manufacturer prior to shipping, the following checks and tests should be performed at a minimum to ensure that a new low voltage circuit breaker is ready to be placed into service.
Electric shock occurs when your body becomes part of a closed circuit and electric current flows into one part of your body and out another, like into your hands and out of your feet for instance.
Direct current (DC) is generally less dangerous than alternating current (AC).
One major element of a transformer maintenance program is periodic testing of its insulating fluid - and obtaining a good fluid sample starts with knowing where to draw the sample from.
Most commonly referred to as simply a "megger," the insulation resistance test set (or Megohmeter) is used to determine the condition of insulation on various types of electrical equipment like cables, transformers and switchgear.
Depending on the model, Square D Micrologic trip units may feature self-protection/advanced-protection (AP) functions in addition to the typical over current functions found on most low voltage power circuit breakers. The AP LED is designed to indicate the following:
Hard hats must be worn when working in areas where there is a potential for injury to the head from falling objects.
Wearing a hard hat is one of the easiest ways to protect the most important part of your body - the head. A head injury can kill you or even impair you for life. Hard hats can protect you from impact and penetration hazards as well as from electrical shock and burn hazards.