The Model 274 3-Phase Current Monitor is designed to monitor all legs of a 3-phase line, and can also be used to monitor three individual single-phase lines. The output relay will energize on an over-current condition on any one of the 3 monitored lines. Two indicator lamps are provided to show when an over-current condition exists and when the output relay is tripped. An adjustable trip delay of 0.2 to 20 seconds is provided to reduce nuisance tripping. Matching current transformers are available to extend the range of the device to most any range up to 1,000 amps. The Model 274 is offered in either manual or automatic reset models. An external power supply of 24, 120 or 230 VAC powers the device.