Low Voltage Breaker Data

Uniquely identifies the equipment item. The program automatically assigns a name, but you can change it, if needed. The name can be up to 16 characters long.

For low voltage breakers, the program automatically assigns the names BL-1, BL-2, BL-3, and so on.

The bus connected to the low voltage breaker, which must already exist on the one-line. Next to the bus name, the Base kV of the bus is displayed.

The phase of the item. Currently, this is for reference only.

Low voltage breakers are separated into three categories:

• LVPCB: Low voltage power circuit breakers
• ICCB: Insulated case circuit breakers
• MCCB: Molded case circuit breakers

These classes of breakers are each listed separately in the equipment field of the device library. Depending upon the class of breaker you select, the list of manufacturers for the breaker class will be available in the Breaker Mfr box.

Provides a list of manufacturers available in the device library. If the desired manufacturer is not listed in the device library, you can add it to the library.

The list of manufacturers shown depends on the class of breaker. Select the class before selecting manufacturer.

Equipment types available from the selected manufacturer. If the desired type is not listed, you can add it to the library.

A type would include a group of models or brands with similar functions.

Select the symbol you want to see on the one-line:

• Breaker Only: LV breaker..........
• Fused Breaker: Fused LV breaker..........
• Breaker Contactor: LV breaker with a contactor...........

Type of trip device or mechanism. Selecting the type of trip device affects the contents of the dialog box.

• For LVPCB class, you can select Solid State Trip or Non-Solid State Trip.
• For ICCB and MCCB classes, you can select Solid State Trip or Thermal Magnetic.

This section is available for selection only when Solid State Trip or Non-Solid State Trip is selected in the Trip field.

In many cases, the type of trip or the application of the breaker determines the interrupting current of the breaker. Older (pre-1964) low voltage power circuit breakers with instantaneous trips typically have higher interrupting ratings than the same device without instantaneous trips. The LVPCB device library allows instantaneous and non-instantaneous trip ratings. All ICCB and MCCB breakers are equipped with instantaneous trips. The old cascade application for LVPCBs is not supported in this library. However, you can determine this rating and enter the value directly into the Interrupting kA field.

Recent standards allow ICCBs and MCCBs to be rated for series application. This provides increased interrupting kA for some devices. The ICCB and MCCB device libraries allow instantaneous and series rated trip ratings.

Fills in a computed value for the Interrupting kA field, based on the device library entry for Mfr, Type, Style and the base kV. (The Interrupting kA value is based on the breaker multi-pole rating at the 480 volt level.)  You can override interrupting kA by typing in different numbers. This button also causes the appropriate Testing Standard to be displayed for your information. (The Testing Standard comes directly from the device library and cannot be changed.)

Calculation of series ratings: When you calculate the Interrupting kA based on Series Rating, you will first need to define the upstream breaker Mfr, Type and Style. If the library has the series rating data, then the data is imported from the library. If not, the fully rated instantaneous trip value is used.

Select the appropriate boxes to display the tick mark on the TCC plot.

• ANSI: You can display momentary, interrupting, and 30 cycle short circuit values.
• IEC: You can display initial, breaking, and steady state short circuit values. If you select to display breaking values, you can also specify to use a global value or select from a specific value including .02, .05, 0.1, or > 0.25. The global value is set in Short Circuit Options on the Control tab under IEC-60909 Settings.

Enter the corresponding short circuit values in kA in their respective edit fields for phase short circuit and ground short circuit.

This option is only available after you set the Trip and Solid State Trip fields on the Specifications tab.

You can also select or clear it in the Temporary Thermal Magnetic Data dialog box in Coordination mode to avoid plotting the TCC.

Click to view notes recorded in the library for the device. Information may include data sheets or manufacturer's information for the device or assumptions needed to model the device.

The long time pickup and delay are selected in this section. The pickup calculation depends on the device selected. It may include LTPU Mult, but it will include Setting (C) and either Sensor or Plug/Tap. After the settings are selected, the actual pickup in amperes appears in parentheses.

• Setting (C): The long time pickup current setting below which the device will not trip. This is a fraction of the sensor or plug/tap amps. For some trip units LTPU multiple may also be required to set the pickup current.

  LTPU Mult: Multiple of Setting (C), which can be adjusted to “fine-tune” the long time pickup setting. Some trip units may not have this feature.

  Curve: Some solid state curves may have multiple LT delay curves to choose from. This field enables you to choose the curve shape.



Figure 6: LT Delay Curve

• LT Delay: Long time delay setting to select the delay band.

Short time pickup and delay settings. This section is applicable to only devices with short time trip. After the settings are selected, the actual pickup in amperes appears in parentheses.

• Pickup: The short time pickup current setting below which the device will not trip for short time trip. The short time pickup setting may be a multiple of long time pickup, sensor rating, plug or tap value, or the current setting times the sensor or plug/tap.
• (I^x)t: To select shape and slope of delay short time band. When you select In, the (I^x)t function is enabled. The delay band has a slope of minus “x”. When you select Out, the (I^x)t function is unavailable, and the short time delay is independent of the current. For some new circuit breakers, the (I^x)t delay may be adjustable. In such cases, the choices available will be the various possible delay settings.
• Delay: Short time delay setting to select the delay band.

Nominal instantaneous trip amps, multiple, or pickup setting. When you highlight or select a choice, the corresponding trip amps appear in parenthesis.

• Enable Override: Selecting this option disables tripping based on pickup setting. The device trips at an override value that depends on the device style. This feature may or may not be applicable to the device selected.
• Pickup: The instantaneous trip pickup setting.

This check box is only available if the Trip and Solid State Trip settings are selected on the Specifications tab.

Frame and Trip descriptions.

• Frame: This may be the frame size, the largest rating in the range of similar models, or a range of sizes that have similar curves.
• Trip: Nominal rated amps the breaker is rated to carry without tripping.

The long time pickup and delay are selected in this section. After the settings are selected, the actual pickup in amperes appears in parentheses.

• Setting: The long time pickup setting below which the device will not trip. This is a multiple of the Trip amps or the trip unit rating.
• Band: Long time delay band to adjust the delay.

Short time pickup and delay settings. This section is applicable to only devices with short time trip. After the settings are selected, the actual pickup in amperes appears in parentheses.

• Setting: The short time pickup setting below which the device will not trip for short time delay. This is a multiple of the long time pickup.
• Band: Short time delay band to adjust the delay.

This section is for setting the ground fault pickup, the type of delay and the delay time.

• Pickup: The ground fault pickup setting, which is either in amps or multiple of sensor, plug, or setting C.
• (I^x)t: To select shape and slope of ground fault delay band. When you select In, the (I^x)t function is enabled. The delay band has a slope of minus “x”. When you select Out, the (I^x)t function is disabled and the delay is independent of the current.
• Delay: Ground fault delay setting to select the delay band.

This is the ground instantaneous setting used during maintenance to lower the arc flash hazard. The name of this section may be manufacturer specific such as ARMS, Maint Mode, RELT, Quick-Trip, etc. The On/Off switch for the maintenance mode is the check box on the Phase Trip tab.

Select to indicate if the Short Time Trip ZSI is set On. In analysis focus (Short Circuit, Coordination, and so on), ST ZSI can be turned “On” or “Off” temporarily using the right-click context menu.

If you select this option, you can specify the (I^x)t and delay values for the unrestrained settings for the short time ZSI curve.

Select to indicate if the Ground Trip ZSI is set On. In analysis focus (Short Circuit, Coordination, and so on), Ground ZSI can be turned “On” or “Off” temporarily using the right-click context menu.

If you select this option, you can specify the (I^x)t and delay values for the unrestrained settings for the ground ZSI curve.

Equipment types available from the selected manufacturer. If the desired type is not listed, you can add it to the library.

Low voltage fuse styles available from the manufacturer for the type chosen above.

A style may be a brand name or the name of the group of fuses with similar functions.

Equipment types available from the selected manufacturer. If the desired type is not listed, you can add it to the library.

EasyPower can monitor whether or not the IEEE 519 guideline for harmonics is met at the point of common coupling.

If selected, then the Harmonics Report indicates when this guideline is not being met.