How to measure electricity from a safe distance
The foundation of any electrical safety program starts with limiting the exposure of workers to the hazards of shock and arc flash. Safe work practices, including the use of non-contact test tools, allow electrical workers to measure from a safe distance. A few principles guide the selection and operation of the correct tools, including:
- Safe distance measurement - Laser distance meters are generally considered a convenience item, but they can substantially increase safety. When conducting an arc flash study, for example, you'll need to measure the lengths of conductor runs between equipment. Rather than using steel measuring tapes and stepladders with two people finding themselves in precarious positions near and over cable trays and switchgear, the laser distance meter allows just one person to take long distance measurements safely from the floor.
- Non-contact voltage measurement - For quick power checks at a receptacle or troubleshooting a lighting circuit, using a wireless voltage detector is safer than placing probes in a receptacle and much safer than opening boxes and lighting fixtures. Users must be aware that voltage detectors will only indicate power on the ungrounded side of the circuit; not on the grounded or neutral conductor side.
- Remote display - Remote display multimeters allow readings to be taken up to thirty feet (9 meters) away from the equipment being monitored. The display unit is removed from the multimeter while the meter and probes (or clamp) remain at the point of measurement. Safety applications include closing the door on an MCC cubicle or disconnecting and standing at a safe distance to measure motor inrush current. Standing directly in front of a motor starter when a large three-phase motor draws many times its normal running current at startup is no place to be, even if wearing the appropriate PPE.
- Using wireless tools - By utilizing wireless tools, workers are able to stay outside of any shock or arc flash boundaries as equipment is operated and various parameters are observed and recorded.
Using non-contact test tools greatly limits and often times completely eliminates the need for workers to be exposed to the electrical hazards of shock, arc flash, and blast. Providing a practical safe working area free of electrical hazards is the stated purpose of electrical safety standards. The use of non-contact test tools can help achieve that goal and create an electrically safer and more efficient work environment.