Attic Thermostat

I need some help installing an attic thermostat. The thermostat has 4 wires inside 1 white, 3 black. 2 blacks are attached to the internal workings of the thermostat and the 3rd is used for power. I know the 3rd black along with the white is used to connect to the power supply. I believe that the other 2 blacks can be used for an on off switch. If I don't want an on off switch, I just cap off the 2 black wires, correct?

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Site Timeline is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.