Abstract: A bus cooling fan that operates without an external electrical power supply. The fan is positioned proximate two bus bars of a polyphase electrical system. The fan includes a rotor supporting fan blades and mounted on an axle. The axle is supported by cross-braces in a shroud surrounding the rotor. The shroud is open at the ends. The fan is fabricated of non-ferrous, non-conducting material with the exception of the rotor. The bent rods which interact with the electromagnetic field created by the current-carrying bus bars of the polyphase electrical system to make the rotor function as an induction motor when the fan is placed proximate two bus bars.

Abstract: An adjustable height spacer for providing rigid support and insulation between the bus bars of an electrical panel. The spacer is adjustable in height to provide various distances between the bus bars. The spacer includes a pair of body members that are axially aligned. A repeating series of teeth of various heights is defined around the margin of each body member at one end. The teeth are configured such that when the toothed ends of two body members having identical tooth patterns are mated, the teeth operatively engage each other to provide a secure coupling when the body member is placed under a compressive force. The height of the body member is varied by rotating one body member with respect to the cooperating body member such that a selected set of teeth within the series is engaged.

Abstract: An adjustable height spacer for providing rigid support and insulation between the bus bars of an electrical panel. The spacer is adjustable in height to provide various distances between the bus bars. The spacer includes a pair of body members that are axially aligned. A repeating series of teeth of various heights is defined around the margin of each body member at one end. The teeth are configured such that when the toothed ends of two body members having identical tooth patterns are mated, the teeth operatively engage each other to provide a secure coupling when the body member is placed under a compressive force. The height of the body member is varied by rotating one body member with respect to the cooperating body member such that a selected set of teeth within the series is engaged.