| A | B |
|---|
| contactor | a larger version of the relay; it can be repaired or rebuilt & has movable & stationary contacts |
| external motor protection | motor overload protection that is mounted on the outside of the motor |
| inherent motor protection | this is provided by internal protection such as a snap-disc or a thermistor |
| magnetic overload protection | this protection reads the actual current draw of the motor & is able to shut it off based on actual current, versus the heat-operated thermal overloads, which are sensitive to the ambient heat of a hot cabinet |
| manual reset | a safety control that must be reset by a person, as opposed to automatically reset, to call attention to the problem; an electrical breaker is a manual reset device |
| motor starters | electromagnetic contactors that contain motor protection & are used for switching electric motors on & off |
| National Electrical Code (NEC) | a publication that sets the standards for all electrical installations, including motor overload protection |
| pilot duty relay | a small relay that is used in control circuits for switching purposes; it is small & cannot take a lot of current flow, such as to start a motor |
| relay | a small electromagnetic device to control a switch, motor, or valve |
| motor service factor | a factor above an electric motor's normal operating design parameters, indicated on the nameplate, under which it can operate |
| solder pot | a device using a low-melting solder & an overload heater sized for the amperage of the motor it is protecting; the solder will melt, opening the circuit when there is an overload; it can be reset |
| time-delay relay | a device that prevents a component from starting for a prescribed time; many systems start the fans & use a time-delay relay to start the compressor at a later time to prevent too much inrush current |
