Service life is determined by the type of transient absorbers used in your protector, and their electrical environment. Most cost-effective designs incorporate metal oxide varistor transorbs, which are sacrificial by design and therefor will degrade if hit repeatedly by large voltage surges, and can even occasionally be blown to smithereens by a single catastrophic event.
Most household applications typically operate in benign environment, so chances are that your Panamax is fine although there's no guarantee of course. If your location experiences significant lightning events that disturb your commercial power, then your transorbs might have degraded over the years.
I believe that Panamax, as well as several other manufacturer's protection PLC's will actually shut off their power output if the internal transient protection feature is not functioning correctly.
Most household applications typically operate in benign environment, so chances are that your Panamax is fine although there's no guarantee of course. If your location experiences significant lightning events that disturb your commercial power, then your transorbs might have degraded over the years.
I believe that Panamax, as well as several other manufacturer's protection PLC's will actually shut off their power output if the internal transient protection feature is not functioning correctly.