UPB Phase Coupler (39A00-1) warm...what is normal

I installed the Leviton 39A00-1 phase coupler a few weeks ago.  Today, I was in the attic where it is installed next to the panel and touched it.  I was kind of surprised when it felt warm; not hot or dangerous.  When took a Infrared Temp of it, it was running around 104F.  The attic wall next to it was around 94F.  Air temp was...well, hot up there!  I'm almost certain it is hooked up correctly to a 220 breaker that controls one of my HVAC air handlers.  Does this sound normal; or could someone see what their Phase Coupler temp is running or if it feels warm to the touch?  I think I am OK, but just wondered what others were experiencing.

mine is 95 degrees in a room that is 73 degrees.

Thanks rockinarmadillo.  Glad to know that it's supposed to generate a little heat!

Here still have a phase coupler installed along with my repeater. 
 
They are on separate breakers such that the phase coupler is off right now and the repeater is on.
 
Will check out temps with my little portable temperature tester.  Really never have paid attention.

Yes they do get warm.  They are pretty simply devices but the main component is an AC rated capacitor.  If the capacitor was "perfect" it would have no wattage lose but being the real world hey dissipate 4 or 5 watts of heat.