B&B Electronics’ Model 232SP9 protects RS-232 ports from damage caused by large voltage peaks from lightning and other power problems. The Surge Protector uses 600W Transient Voltage Suppressors to protect all 9 pins. It has one DB-9 male and one DB-9 female connector with all 9 pins passing straight through. The TVSs are connected between the ground screw and pins 1,2,3,4,5,6,7,8, and 9. The 232SP9 will suppress any voltage levels above 12 volts without affecting the normal RS-232 data.
The 232SP9 is placed inline, between the data cable and the RS-232 port, as close to the protected port as possible. The ground screw must be connected to earth ground. A minimum of 12 AWG copper wire is recommended. B&B’s Model CU15B is 1.5 x 0.016 in (38 x .25 mm) copper cut to length for ground connections that are longer than a few feet (one meter). If this device is not properly grounded it will not protect RS-232 lines.
