Simple ESD protection for MOSFETS
If the gate is truly connected to a terminal block, it is vulnerable and needs to be protected. A series resistor and TVS diode would be my first stop at protecting it.







simulate this circuit &ndash; Schematic created using CircuitLab

A cap in parallel with the TVS will help slow the ESD event down, if you can afford the added capacitance on the gate, and give the TVS a little more time to turn on. Make sure the traces are short as possible and the TVS has a solid ground connection. A regular Zener diode is just too slow for ESD protection. It's better than nothing, but at that point, your primary means of protection will be the MOSFET's internal clamp, if it has one.