Fire Hazard Using Surge Suppressor
During the 1980s and during most of the 1990s, surge suppressors were sold in the USA with very little engineering design. Many of these suppressors were nothing more than a varistor inside an outlet strip or other enclosure, with no testing for coordination with arresters and no testing for fire hazards during temporary overvoltages, such as would result from disconnection of the neutral wire in 120/240 Vac electric systems that are common in offices and residences in the USA.

As a consequence of the lack of careful engineering design and testing, at least tens of millions of surge suppressors sold in the USA prior to 1998-99 are hazardous.

In my opinion, many surge suppressors sold in the USA before 1998-99 have a design defect, as that term is used in products liability law. The most common specific design defects are both:

1. use of varistors with a MCOV rating of 130 V ac, and
2. no thermal disconnector when the varistor is inside a plastic enclosure.

My opinion is not the result of applying knowledge in the late 1990s to products designed and manufactured during the 1980s and early 1990s. As mentioned above, General Electric took appropriate steps in the design of its surge suppressors in the late 1970s. And, as mentioned below, there are several archival papers published in proceedings of international engineering symposia from 1989 to 1992 that discussed problems with MCOV ratings that were too low or the lack of a thermal disconnector.

Furthermore, some manufacturers and importers of surge suppressors were well aware of the fire hazards in their products, because of consumer complaints and warranty claims to those manufacturers and importers. Yet these manufacturers continued to sell products that I believe were defectively designed, and these manufacturers also resisted efforts to include safety tests in ANSI/IEEE engineering standards.