Amps / HP rating – and there is a difference. The life of any float switch is lengthened or shortened based on the number of amps switches (which is another great reason to use that 0.25 Amp Relay or contactor mentioned above). The amp rating is exactly that. The Horsepower rating refers to the inrush current of a motor and what the microswitch internal to the float switch has been tested at.
NO, NC, or combined. Generally, if you have multiple float switches in the same vessel, they will all be the same style.
Material & Chemical Compatibility: Wastewater can be corrosive or have oil/chemicals. Ensure the float’s body and cable material will resist whatever is in the water. Oil and Gas don’t play well with plastic. Stainless steel or engineered plastics may be needed for hot or chemically aggressive wastewater
If using high horsepower pumps, choose a float or control system designed for that load (or use it with a relay).
Mounting & Configuration: Consider how it will be mounted and used. In a deep sump, you might need a long cord length to reach your control box – make sure the float comes with a sufficient cable. Think about the tether length or rod length needed for proper on/off levels. Also decide if you want a piggyback plug float (very easy to install with plug-and-play, for 120–230V single-phase pumps) or a float with bare leads to hardwire into a control panel
Environmental/Safety Ratings: For industrial settings, check the float’s temperature rating if your wastewater is hot, and whether it’s rated for sewage/effluent use (some have higher protection against fouling). If the environment is hazardous (combustible gases in a sealed wet well), you may require an intrinsically safe float circuit, meaning the float connects through a safety barrier or an explosion-proof rated control panel. Also, if local regulations restrict mercury, opt for a mercury-free switch
Reliability and Reviews: In an industrial context, a robust design pays off. Look for floats marketed as heavy-duty or industrial grade, with features like strain relief on the cable, solid polypropylene or stainless floats, and possibly double-sealed cables. User feedback from forums or suppliers can highlight if a particular model tends to fail or if it’s very dependable. (If your system has a history of float failures, consider upgrading to a more corrosion-resistant or durable float switch to reduce downtime