Protective Devices that can be Auto Coordinated

Relays

The device function type selection in the System tab of the Relay dialog box is important when determining the type of auto coordination being selected. For phase auto coordination, all Dev Fctn Type with Phase OC is included as a dependency. The same applies for ground coordination of relays as the auto coordination uses functions that have Ground OC selected in Dev Fctn Type column. All relays with Dev Fctn Type selected as Other or Differential are not used by auto coordination. Also, only functions where the Plot TCC check box is selected are included in auto coordination. See the figure below for examples.

SSTs and Molded Case Circuit Breakers

Phase auto coordination of an SST or molded case circuit breaker uses the information provided in the Phase tab of the breaker dialog box. For ground auto coordination, the appropriate data needs to be entered in the Ground tab of the breaker dialog box. If you do not want phase or ground settings to be used in the auto coordination process for a particular device, clear the Plot TCC check box under the appropriate section of the breaker dialog box.

Fuses

When auto coordinating a fuse, the fuse size is modified in the database. However, the auto coordination report shows comments regarding the coordination of the fuse with downstream equipment. If you do not want the fuse curve to affect auto coordination of upstream devices, clear the Plot TCC check box on the Specifications tab.

Next: Auto Coordination Process

More Information

• Auto-Coordination
• Auto Coordination Options
• Auto Coordination Process
• Auto Coordination Report