Potential Starting Relays  July 3, 2006 Figure 1 This month's
article will cover theory and operation of potential starting
relays. The article that will appear in the Aug. 7 issue will
cover potential relay ratings and specifications along with
systematic troubleshooting.  Potential or â€˜voltage' starting
relays are used with single-phase capacitor-start/capacitor-run
motors, which need relatively high starting torque. Their main
function is to assist in starting the motor. These starting
relays consist of a high-resistance coil and a set of normally
closed contacts. The coil is wired between terminals 2 and 5,
with the contacts between terminal 1 and 2. Terminals 4 and 6
are used for capacitor and/or condenser fan connections and have
no electrical significance to the starting relay itself (Figure
1). Terminals 4 and 6 are sometimes referred to as dummy
terminals and are simply used for wire connections.  Fig. 2
shows how a potential starting relay is wired to a capacitor-
start/capacitor-run compressor mot