Do you mean the pump to drain the shower or the pump for the water feed? The pump to drain is triggered by the float switch, I don't believe there is a relay, and the feed pump I believe is pressure / flow initiated.
Pump drain sump has 4 wires 2 for the float and two for the pump. When the float makes the pump is energized and indicator lights at both helm stations go on. Float isn't wired in series with the pump.
