ABB introduces an arc flash mitigation solution to protect operators and equipment

2017-04-25 - Many industries are facing internal or external deadlines to implement arc flash (AF) mitigation solutions within their facilities. ABB now offers ArcLimiter™, an arc flash mitigation solution that is unique in the industry. It solves the low-voltage (LV) arc flash problem at the medium-voltage (MV) system level.
Arc flash is an electric arc and can occur in an electrical installation for several reasons, such as human error or bad connections. Accidents are quite unusual but when they happen, their consequences may be very severe. Operators are always exposed to these risks when working in the switchgear room in equipment proximity. Flames, ejected parts, smoke and overpressure are the main effects of an arc fault in a non-arc classified switchgear. When the fault happens in an arc-classified switchgear not equipped with gas outlet, smoke is released in the room. Noise level during the fault can be also very dangerous in all circumstances.

ABB ArcLimiter™ is a tested solution that significantly mitigates any LV and MV arc flash hazard, protects the upstream transformer from the voltage sags normally seen during an incident and solves the power quality problem created by any fast grounding or shorting solution to arc flash mitigation.
By fast clearing the arc flash event with a coordinated operation, voltage disturbance is minimized and it greatly improves operation of all the sensible electronic equipment that are so critical to everyday modern life from shopping malls to sensible installations such as hospitals and data centers.
The solution consists of ABB’s proven technology called Ultra Fast Earthing Switch (UFES), REA arc flash relay on the LV side and MV current limiting fuses.

The speed of response to an arc flash incident is less than 4ms, much less than one tenth of the clearing time of a normal circuit breaker and protection relay. ArcLimiter™ can reduce incident energy to below 1.2 cal/cm2 to lower Hazard Risk Category to zero so that Personal Protective Equipment (PPE) is not required to work with LV and MV switchgear.

ArcLimiter™ is easily adaptable and integrated in to existing systems and equipment through a study and engineering. Improved power quality reduces the severity of voltage sags due to fault conditions. It limits the likelihood of the drop out of various industrial equipment located upstream of the arc fault such as adjustable speed drives, motor starters, control relays, PLC and computers.

Arc flash may happen across all industry applications worldwide but some countries, like US, are more sensitive to this issue due to the large installed base of non-arc classified switchgear. Specific safety regulations and standards like OSHA’s regulations and NFPA 70E address electrical safety requirements and require the evaluation of the arc flash boundary, incidence energy and personnel to wear appropriate PPE.

The solution is appropriate for industry, commercial facilities, educational campuses, any facility applying primary loop fed transformers with fused MV switches (36 kV limit) in new or existing applications and facilities having MV to LV transformers in the range of 750 KVA – 5000 KVA.