AE series controls are Lead/Lag style duplex controls with advanced programming options for duplex (2-pump) sewage and grinder pump systems.
Unlike standard duplex panels, which only alternate pump operation, Lead/Lag control allows for simultaneous use of both pumps if the wastewater level gets high enough and 1 pump is not sufficient to remove the extra water volume.
This particular model comes with (3) float switches - Off (turns one or both pumps off), Lead-On (turns on the Lead pump) and Lag+Alarm (engages the Lag pump and activates the alarm). These floats must be mounted on one of the pump's discharge pipes or onto a separate float tree (if available) inside the basin and wired to the corresponding terminals inside the control panel. "Test" button (next to each float terminal) in the panel can be used to customize operation and change which float positions trigger alarm & beacon.
The panel has a Lead/Lag/Alternating selector switch which can either assign one pump as a primary (Lead) and the other as a secondary (Lag/backup), or can alternate between them (best option if both pumps are the same). It also has a separate Hand/Auto/Off switch for each pump for either manual operation (usually, for testing), automatic mode (normal operation) or off mode (for maintenance, repair, replacement, etc.).
An external Test/Normal/Silence switch can be used to test the horn & beacon or to silence the alarm if needed.
AE21L=3 is rated for indoor installation only and is suitable for pumps that are at or below 1 HP (up to 14.9A) each.