060L5201, Danfoss, Thermostat. KPU61, KPU thermostats are temperature-controlled electrical switches for regulation and safety monitoring of refrigeration and air conditioning systems. KPU sensors are available with vapor charge or with adsorption charge.Thermostats with adsorption charge are widely used to give frost protection, while vapor charged sensors are used where small differential is required. All KPU temperature controls have a single pole double throw (SPDT) contact system.