Auto Coordination Options

Enables you to decide how to proceed when a protective device to be coordinate does not contain trip data. The choices are:

• Automatically Skip Device: Skips the device with incomplete data and proceeds with other devices. The protective device is not used in coordination. The auto-coordination process reports incomplete data for protective device without data.
• Cancel Auto-Coordination Run: Stops the entire Auto-Coordination process.
• Prompt to Skip or Cancel: Enables you to decide one of the above two methods during the auto coordination process by providing a message.

The trip settings are set as selected below, if the curve cannot be coordinated with other equipment because of insufficient data.

Set LTPU to: Select the type of load current calculation to use to set LTPU. The following choices are available:

• Connected Amps: Amp value for the total kVA of all downstream loads.
• Demand Amps: Amp value for the total (kVA * Demand Factor) of all downstream loads.
• Code Factor Amps: Amp value calculated using appropriate code factors and demand factors, following a Code (such as NEC).
• Design Amps: Amp value calculated using appropriate code factors and diversity factor and Design multiplier.

If zero, then: If the selected load type amps are equal to zero, the LTPU is set as selected. The possible LTPU selections for this case are Min, Medium, and Max.

Set STPU to: Select the setting for STPU if coordinating equipment does not have sufficient data or coordinating equipment is not present. The possible STPU selections are Min, Medium, and Max.

Set INST to: Select the setting for INST if coordinating equipment do not have sufficient data or no coordinating equipment is present. The possible STPU selections are Min, Medium, and Max.

Select the amount of precision used while coordinating between curves. Selecting a higher level of precision will enhance coordination. There are three levels of precision are shown below. The default level of precision is Normal (fastest).

• Normal (fastest)
• High
• Aggressive (slowest)

The selected level of precision will affect the amount of time needed for EasyPower to auto coordinate each selected protective device.

Select the analysis:

• Phase Only: Auto coordination only coordinates phase settings.
• Ground Only: Auto coordination only coordinates ground settings.
• Both Phase and Ground: Auto coordination coordinates phase settings and ground settings at the same time.

The program will take into consideration the 87% factor while comparing primary currents with secondary in a wye-delta transformer with line-to-line fault on the delta side.

This enables you to view comments regarding auto coordination of equipment, without changing protective device settings in the temporary database. When the check box is not selected, the settings are changed temporarily in Coordination focus. These changes need to be stored to the database when returning to Database Edit focus if you want to save them.

The table is the NEC Table 450-3(A) for transformer primary over 600V. The table shows the maximum rating or setting of over current protection for transformers. You can change the values in the spreadsheet.

When setting SST for transformer FLA, the LTPU is set based on the following selections:

• LTPU setting amps: LTPU setting is set based on LTPU amps.
• LTPU min tolerance amps: LTPU setting is set based on LTPU minimum clearing curve amps.

Selecting the check box increases LTPU setting by one past the selected transformer FLA NEC limit. If the check box is not selected, LTPU is set as originally specified.

LTPU coordination is selected by coordinating with other protective devices or with maximum transformer FLA.

• Use closer selectivity with downstream protective devices: LTPU setting is set based on coordination with downstream protective devices.
• Use Max transformer Amps: LTPU is set based on maximum transformer amps.

Select the cable protection method from the following:

• LTPU settings amps: Adjusts LTPU settings of solid state trip such that the LTPU nominal amps are lower than the downstream cable.
• LTPU min tolerance amps: Adjusts LTPU settings of solid state trip such that the LTPU minimum tolerance amps are lower than the downstream cable.

When the check box is selected, LTPU setting is set to the next setting past the cable ampacity. As per NEC, this is enabled only when the amp rating is 800A or less.

Enables you to select the method for coordinating solid state trip and cable.

• Use closer selectivity with downstream protective devices: The solid state trip device coordinates with downstream protective devices.
• Use line ampacity: The cable ampacity is used to set the LTPU setting amps, without comparing with downstream protective devices.

Select the type of load current calculation to use to set LTPU. The following choices are available:

• 100% Connected Amps: Amp value for 100% of kVA load.
• Scaled Connected Amps: Amp value for the scaled kVA of load.
• Demand Amps: Amp value for the total (kVA * Demand Factor) of load.
• Code Factor Amps: Amp value calculated using appropriate code factors and demand factors, following a Code (such as NEC).
• Design Amps: Amp value calculated using appropriate code factors and diversity factor and Design multiplier.

Select one of the following STPU settings when coordinating with a single load: Min, Medium, or Max.

Trip curve will be set outside tolerance boundary when comparing with Motor FLA. The range is –50 % to 50 %.

Trip curve will be set outside tolerance boundary when comparing with Motor Locked Rotor Amps (LRA). The range is –50 % to 50 %.

Trip curve settings will be set outside tolerance boundary when comparing with Motor Asymmetrical inrush amps. The range is –50 % to 50 %.

When a relay has only cables as downstream equipment, the Tap is set to the specified value times the ampacity of cable.

When a relay does not have dependencies, its time dial is set such that the relay trips close to the specified time at the maximum short circuit current available at the CT for the relay. You can also have the time dial set at the specified value instead of basing it on the short circuit current.

The instantaneous is set to the specified multiple of maximum short circuit current.

The desired minimum time difference between two relays is the sum of Over Travel time, Safety Margin, Auxiliary relay time, and circuit breaker opening time. The time dial settings available in a relay may not provide the exact desired minimum time difference. This Minimum Gap Tolerance enables you to set the time delay of the relay up to the specified percentage higher than the desired minimum time. For example, the desired time difference between two relays is 0.283 seconds. If the Minimum Gap Tolerance is 20%, the program lets the upstream relay time dial to be set such that the time difference is not greater than 0.33 seconds (0.283 + 20%).

This is the factor used in setting instantaneous pickup. A factor of 1.1 corresponds to a 10% tolerance. For example, if the downstream relay has instantaneous pickup of 3000 Amps, then the upstream relay pickup needs to be higher than 3300 Amps (3000*1.1).

: Select the number of taps/pickup settings program processes through to determine the optimal relay curve settings. There are three (3) precision selections:

• High (Most Taps viewed)
• Medium
• Low (Least Taps viewed)

Solid state relays typically have dc offset filters so that trip characteristics are based only on the AC component of currents. The relay library has data indicating whether the relay has a dc offset filter. The DC component may not be completely filtered.

When this check box is selected, the programs uses the asymmetrical currents (with dc component) it calculates. If the check box is not selected, the offset specified in the field below is used.

If the Use Calculated SC Asym Offset check box is selected, then the specified value will not be used.