You need to be sure they are "motor run" types that are designed to have
continuos 60Hz AC across them 24 hours a day. The cheaper motor run types
only are on for a few seconds while the motor spins up then the voltage is
removed from them. Internally, the motor run types are built better with
oil/poly construction. The motor run types often have paper in oil as a
dielectric and they will get hot fairly fast.
I would check before plugging them in. When you look at them, it is
obvious having one explode would be a "bad" thing...