For a relay controlling an inductive load, does a bi-directional transorb make any sense as an alternative to the usual capacitor in series with a resistor snubber? This is 120 VAC, not RF, a relay controlling a motor and a second relay controlling a solenoid.
I use to use the 1.5KE160C's as AC input clamping devices and they worked quite well. They are very fast and don't have the same wear out mechanism that MOV's have. MOV's in time, will reduce their clamping voltage until they come into the steady state voltage region that they are protecting and then that's it for the life of a MOV. Transorbs are more like fast zeners and do not have this slopping cure after multiple hits. The restriction is the amount of energy during an transient condition they can handle.
Here is a data sheet showing the unidirectional and bi-directional device offerings. Generally the "C" in the part number indicates a bi-directional device which you would use for AC clamping applications.
Joe, W3GMS