UL 1449

Underwriters Laboratories’ safety standard for Surge Protective Devices (SPD), formerly known as Transient Voltage Surge Suppressors (TVSS). These SPDs typically use metal oxide varistors (MOVs) as clamping components which divert surges to the ground line. This is sacrificial technology that wears out with use.

UL 1283

Underwriters Laboratories’ safety standard for electromagnetic interference filters. Zero Surge’s non-MOV series mode technology uses filters to suppress worst case surges and remove EMI/RFI noise disturbances from the power line. This technology is not sacrificial and does not wear out with use.


Underwriters Laboratories’ safety standard for relocatable power taps. These are moveable plug-in power strips with three or more outlets. If they contain other electronic components intended to provide electrical noise filtering or surge protection, they would also be tested under UL 1449 or UL 1283. They generally have an on/off switch, several outlets, a circuit breaker, and a bendable cord.

A-1-1 Certification

The U.S. Government’s highest classification for surge suppression. All Zero Surge products meet the A-1-1 Classification.

Grade A is the best endurance – 1,000 surges of 6,000 volts / 3,000 amps with no degradation.

Class 1 specifies the best voltage suppression of 330 volts peak for 6,000 volts / 3,000 amps surges.

Mode 1 is Line to Neutral (L-N) suppression. This avoids ground wire contamination and is recommended for interconnected equipment.

CSA 22.2 No. 8-M1986

CSA Group’s safety standard for electromagnetic interference filters. CSA Group is the largest standards development organization in Canada. Zero Surge’s products are certified to meet this standard.