Bourns® Switch Grade Fail-Short device is designed to be the most reliable and safe fail-short device on the market. Many other GDT manufacturers use either a burn-through or solder pellet design, both of which can have limitations in supporting significant, longer duration AC power faults at temperature extremes. In Bourns’ view, the burn-through design is unreliable due to residue which may remain as the fail-short activates which can cause higher contact resistance and thermal runaway. Bourns uses a spring clip with a standoff support in its design. The support holds the clip away from the GDT outer electrodes with a eutectic solder joint. Under extended AC fault, the GDT heats to the point that the joint releases causing a snap action release of the fail-short, diverting the current to ground. This process should eliminate concerns of high contact resistance or partial closure of the fail-short mechanism within rated limits.