The Disconnect Switches:

Handle to open or close the switch

Pump #1                  Pump #2

Pump #3

The Disconnect Switches for Pumps #1 and #2 should always be ON (UP) whenever normal operation of the SPS is desired.  The main purpose of the Disconnect Switches is to be able to lock the pumps OFF if pump maintenance or replacement is needed.  This insures safety for the person working on the pumps.

The Disconnect Switch for Pump #3 should normally be in the OFF (DOWN) position.  This is to prevent the pump from running because the outlet valve next to the Overflow Tank is normally closed (to be explained later).  The pump should NEVER run when the outlet valve is closed or pump damage can result.  Therefore, for safety purposes, the Disconnect Switch should be OFF unless it is desired to pump down the Overflow Tank.  This procedure is explained later.

Control Panel Discussion:

In Normal operation, the Control Panel automatically controls the two main pumps in the Wetwell.  For this reason, the Disconnect Switches must be ON, and the HAND-OFF-AUTO switches must be in the AUTO position so the float switches in the Wetwell can control the pumps.  Other positions of these switches should be used for testing purposes only, because in the HAND or OFF positions, the pumps cannot work automatically.

     The third pump, Pump #3, is in the Overflow Tank, which is only used if there is some sort of failure and the sewage overflows into that tank.  Pump #3 therefore will be rarely used.  However, it is still important to occasionally check the operation of the Overflow Tank system.  By leaving the Pump #3 HAND-OFF-AUTO switch in the AUTO position, it is easy to see whether or not the float switches in the tank are “telling” the Control Panel to turn on power to Pump #3—that is, a high level condition.  Unless there is a high level condition, the AMBER light for Pump #3 should NEVER be ON.

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