Electrical safety during system testing – the whole is greater than the sum of its parts

18 June 2013

We’ve all heard the saying, “The whole is greater than the sum of its parts”.  And although when we hear this phrase it usually is in reference to people working together as a team, it absolutely holds true when discussing electrical safety during system testing.

When preparing for a job, electrical safety should be the first order of business; however, it is often taken for granted.  Carelessness and inattention, as well as a lack of sufficient knowledge can produce unsafe, and at times, life-threatening consequences. Electrical safety, when preparing to test a system, needs to be thought of in three separate parts: Safety of the test equipment, safety of the procedure and safety of the item under test. If all three of these parts are not assessed thoroughly, systematically and cohesively, the risk of injury to the technician performing the test is great.

So, how do we remedy this?  It’s simple!  Beware of focusing entirely on one aspect of testing while thinking all the others will take care of themselves…because they won’t.

One of the most important things to think about when doing system testing is the degree of protection against arc flash. Arc flash can prove to be devastating if an individual is in close proximity of it since electric current leaves it’s intended path and travels through the air, looking for a place to land… which could be another conductor, the ground or the equipment operator! Arc flash protection is covered by standard EN61010-1:2001, which specifies general safety requirements for electrical equipment intended for professional, industrial process and educational use.

Equipment operators must first understand the category (CAT) rating system then apply the instrument accordingly.  The degree of protection against arc flash is interpreted as a CAT rating, plus voltage limitation.  Its CAT rating defines the level of spike or surge transient that the instrument has been designed to withstand. Insulation testing is yet another way of protecting oneself from harm.

Megger’s industrial insulation testers offer a wide range of features making them ideal for use by utilities, industrial and commercial electricians as well as maintenance and service/repair engineers.  The testers are suitable for use in high energy systems throughout the electrical, power and telecommunications industries.

Additionally, ground testers also safeguard against accidents.  A ground test is usually performed on electrical wires to ensure that they are able to resist current overload. Grounding makes sure that electricity doesn't build up and cause damage to wiring, outlets and devices that use current. It diffuses excess electricity away from a device or system into the ground.

The DET4 series is Megger’s established family of grounding test instruments.

The most important line of defense in electrical safety is a well-trained, alert operator. No matter how good an instrument’s features are or how many instruments you have to test with, if the operator is not well-trained and doesn’t know the warning signs of danger or how equipment works, an accident will happen.

So remember, when assessing electrical safety think of it as three separate parts: Safety of the test equipment, safety of the procedure and safety of the item under test. As they say, the whole is always greater than the sum of its parts.