phase a phase b phase c and neutral the mov groups 14 are shown schematically in fig2 and labeled with reference numbers 14 a 14 h in addition surge protection device 10 includes a number of outputs 16 labeled 16 a 16 d with each output 16 being associated with a respective one of the mov groups 14 a 14 d surge protection device 10 is structured using for example a number of transistor devices e g fets such that when configured as shown in fig2 each output 16 will have one of the following two states i 0 5v if all of the movs in the associated mov group 14 are fully operational and i ground if any i e one or more of the movs in the associated mov group 14 has failed e g due to the occurrence of a surge condition similarly surge protection device 12 also includes a number of outputs 16 with each output 16 being associated with a respective one of the mov groups 14 e 14 h like surge protection device 10 surge protection device 12 is structured such that when configured as shown in fig2 each output 16 will have one of the following two states i 0 5v if all of the movs in the associated mov group 14 are fully operational and i 0 0v if any i e one or more of.