The Insert 3-point Thermostat Control Wire command is used to insert a thermostat control wire on the drawing using 3 points to define an arc. The thermostat control wires are not linked to the database. The thermostat control wire is inserted as a standard AutoCAD polyline and can be modified using standard AutoCAD commands once it is inserted.
To insert a 3-point thermostat control wire, go to
Ribbon: DM HVAC->Drafting-> 
Insert 3-point Thermostat Control Wire
Pulldown Menu: DM HVAC->Drafting Tools->Insert 3-point Thermostat Control Wire
You will be prompted to specify the starting point of the thermostat control wire.
Start point:
You then will be prompted to specify the second point of the thermostat control wire.
To point:
Finally, you will be prompted to specify the end point of the thermostat control wire.
To point:
A polyline will be inserted on the drawing using the 3 specified points.