Waterworks High-Voltage Switchgear

A waterworks fears power loss the most. If power goes out, a whole area has no water. So we did three things for reliability. First, we add dual power with automatic transfer. Two incoming lines plus one tie cabinet. When the main line loses power, the backup line comes on automatically. We tune the switch time to under 1.5 seconds. The pump does not stop. The pipe pressure barely drops. Last year we did a project for a county waterworks. The pressure change was only 0.02MPa. The residents did not feel a thing.

Second, we add T1 surge protection. The discharge capacity is 25kA with a 10/350 microsecond waveform. It can take a direct lightning strike. Waterworks are often in the suburbs and get hit by lightning. One of our clients had two PLCs burned each year before adding surge protection. After using our cabinet, no damage for two years.

Third, we add differential protection for the pump motor. Big pump motors need this. It can tell the difference between an internal fault and an external short circuit. No false trips. We also add stall protection. If the pump jams, it stops within 0.5 seconds. This saves the motor. A small detail: our cabinet door has a tempered glass window. The staff at the waterworks read meters every day. They do not need to open the door. In winter it is warm. In summer it is cool.