When hardwiring SPDs to an electrical system following our SOLID (note make SOLID a link to our Design guides) protection recommendation. The manner they are installed can maximum or reduce their effectiveness depending upon the length of connecting cables. In addition, cable dressing and disconnect selection location can further enhance protection performance as well.

Maximizing SPD performance can easily be remembered by memorizing the following S.O.L.I.D. acronym, and should be installed using the STP steps. Just like the fuel additive STP improves engine performance, surge protector installations are enhanced if they are installed using the STP steps. Each letter stands for the following:

S – SPD connecting cables should be as short as possible. This may require that the surge protector be installed adjacent to the distribution equipment that is being protected. This allows for short cable installations. Long connecting cables add excessive impedance resulting in larger “installed” Voltage Protection Ratings

T - Twisting cables reduces impedance canceling the magnetic effects occurring when surges traverse to the surge protector.

P - When connecting SPD to a panelboard, place disconnecting breakers closer to the neutral or ground buss. This reduces the separation loop area between the phase and ground and/or neutral buss, which lowers the SPD connecting cable installation impedance compared with installations using breakers further stay away from the neutral or ground.

Installing surge protectors following our STP steps will ensure maximized installed protection is achieved. If you need further installation assistance, please email or call our technical support group at (800) 237-4567.