Model: NHD 3 Pole NTH-2.5 Thermal Overload Relay 1.8-2.5A. 3 pole Overload Relay. 2 pole is for regular, general machine overload protection. Difference between 3 Pole and 2 Pole 3 pole is for extra protection, quick disconnect (to protect the motor from wrong wiring), and sensitive machines.
