Metron series M700 solid State, reduced voltage, automatic fire pump controllers provide "Soft" starting and "Soft" stopping of electric motors. This solid state starting method reduces the inrush current and mechanical shocks associated with other conventional reduced voltage starting types. At start-up, a break away current is provided, followed by a timed ramp-up to 500% of the motor's full load amps. Initial current steps as well as current ramp time are completely adjustable to provide optimum starting in any electrical motor driven fire pump application. The solid state unit is supplied with the following features:

• Instantaneous Overcurrent Detection
• Shorted SCR Detection
• Phase Loss Monitor
• Heatsink Over Temperature Switch

In addition, The M700 series can be supplied with all of the other proven standard features found in the complete line of Metron electric fire pump controllers.

Function

The M700 series Soft Start electric fire pump controllers utilizes a state of the art solid state motor controller. The motor voltage is raised to an intitial torque value (an adjustable value of locked rotor torque). The motor voltage is gradually incresased during the acceleration ramp time, (adjustable from approximately 3 to 30 seconds).

After a minimum run period and all starting causes have returned to normal, the solid state controller will initiate a stop sequence. This furncion will reduce surges in the pumping system during stopping a centrifugal pump by smoothly decelerating the motor at a selectable rate.