For GR-1089 Port Type 3, this outdoor application needs very robust protection. The SEP component provides a surge withstand rating of 500A based on the 2/10µS waveshape. It provides a “flow-through” solution so that a stub connection is not required on the line side. It is only connected in a differential manner, with no ground reference connections. This component does require a high impedance connection for its two bias inputs to keep its off-state capacitance low and unchanging so that it does not interfere with the rate and reach of the Ethernet signal. The TeleLink fuses will survive surges up to 500A 2/10µS and thus not resulting in nuisance openings during lightning induced surge events. The tertiary protector will provide the remaining protection for any energy that gets coupled across before the transformer saturates and before the secondary protector starts to limit. The ground reference of this tertiary protector must be connected to the Ethernet PHY ground reference and NOT to any line side ground reference.