High power solid state load relays with integrated heatsink din rail mounting crydom ckrd2420 this 20a solid state relay has a control voltage range of 4 to 32v dc and features an integrated heatsink that provides efficient thermal management the safe and easy to use terminal connections and the din rail mounting design make this ssr quick and efficient to install optically isolated scr output enables high switching load capacity in industrial applications crydom ckrd2420 solid state relay