3 Installation and Wiring Precautions for Safe Use • Firstly, wire the twisted power line to the terminal block, then install the terminal block to the NB Units. Use power lines with AWG#12 to #26 thick, peel the coating 6.5 mm length, followed by tightening the screw with 0.3 to 0.5N torque. Make sure the screw of the terminal block is tightened firmly. Only NB3Q-TW …… B has a different pin arrangement of the terminal block. Do not make use of the terminal block of NB3Q-TW …… B for other equipments. Grounding The NB unit has a functional earthing terminal ( ). Arrange the wiring according to the following conditions.
1 When a potential difference occurs between the NB Unit and the host, arrange the earthing as illustrated. If the distance is too long to realize a single-point earthing, do not ground the earthing terminal of the NB Unit. 2 When the NB Unit, and noise source equipments such as motors and inverters, etc. are installed on the same panel, do not ground the earthing terminal of the NB unit. NB7W CP1E To prevent malfunctions caused by noise, ground the Unit correctly. 3-6 NB-series Programmable Terminals Startup Guide Manual(V109) Precautions for Safe Use