Coordination of Surge Arresters and Suppressors for Use on Low-Voltage Mains

A secondary arrester is used at the point of entry of the mains into a building to provide protection from severe surges, such as direct lighting strikes to overhead mains. A surge suppressor is used at the wall receptacle to protect vulnerable electronic equipment from damage by transient overvoltages. This paper discusses the sharing of current between the arrester and suppressor during surges. Results of both a theoretical analysis and laboratory experiments are reported. Conventional practice is to make the conduction voltage of the arrester greater than that of the suppressor. It is shown that it is better to design the arrester with a smaller conduction voltage than the suppressor, in order to obtain better coordination, better electromagnetic compatibility, and lower cost.