Condensate pumps usually run intermittently and have a tank in which condensate can accumulate. Eventually, the accumulating liquid raises a float switch energizing the pump. The pump then runs until the level of liquid in the tank is lowered. Some pumps contain two switches.. As liquid rises to the trigger point of the first switch, the pump is activated. If the liquid continues to rise (perhaps because the pump has failed or its discharge is blocked), the auxiliary safety switch shuts down the HVAC equipment, preventing the production of further condensate, triggers an alarm, or both.All units, except the 1-ABS, have tanks that range from 0.3 to 1 gallon and are usually supported using the flanges on their tanks or simply placed upon the floor. The 1-ABS pump has no tank at all and is simply placed within a container such as the drip pan of a dehumidifier appliance.