Tool Point of Connection Data

Use the tool point of connection to connect a tool to the one-line. A tool is a piece of equipment that can potentially have multiple different points of connection to the electrical system.

The point of connection represents the combination of both a bus and a load. This combination enables you to perform arc flash calculations on the bus and load as a unit.

This dialog box includes the following areas and tabs:

See Common Tabs for information on the Location, Reliability, Comments, Hyperlinks, Media Gallery, or Collected Data tabs.

Figure 1: Tool Point of Connection Data Dialog Box

Connection Information

Option Description
Tool ID The identifier for the tool. You can select from the list, or click Tools to create a new tool. See Edit Tools for more information.
Ref#

The reference number for the point of connection. This information appears on the one-line.

Base kV

Base kV for the tool point of connection. Note that the tool point of connection must have a kV entered before equipment can be connected to it. Anything less than 1 kV is considered low voltage, anything 1 kV or more is high voltage.

Phase

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

Tool Type This represents a type of tool.
Facility The facility where the tool point of connection exists. This information comes from the tool. See Edit Tools for more information. Facilities are set up under Tools > Options > Facilities.
Func. Area The functional area where the tool point of connection exists. This information comes from the tool. See Edit Tools for more information.
Bay The bay where the tool point of connection exists. This information comes from the tool. See Edit Tools for more information.
Lock Auto-Sizing When this check box is selected, the tool point of connection cannot be auto-sized.

Specifications Tab

Option Description

Bus Data

Power Type

Select the power type for the equipment. The options are:

  • NPS: Normal Power Supply. For example, a power supply that has no backup.
  • CPS: Critical Power Supply. For example, a power supply that includes an uninterrupted power supply backup.
  • EPS: Emergency Power Supply. For example, a power supply that uses a generator for backup.
Bracing (kA) Short circuit rating of bus bracing in kA.
Rating (A) Continuous current rating of the bus in amperes.
Area

Area numbers are used to uniquely define different areas of the electrical system. These areas can then be used for creating specific text reports from analysis operations that represent subsets of the system. For example, typical paper plant areas may be the power house (Area 1), caustic plant (Area 2), pulp mill (Area 3), and paper machine (Area 4). Area numbers are positive integers between 1 and 999.

Zone

A zone number is simply a sub-area. This enables even more specific reporting. You may want to define the pulp mill as Area 3 and the digester electrical equipment as Zone 2. Specific reports can then be generated for this combination without including the entire pulp mill or the other digesters.

Description Description for the bus.
Fed By Use this field to indicate the transformer or the power supply source feeding the bus.
POC (Point of Connection) Data
Unit The unit for the point of connection. Select from CSA, metric, or U.S.
Library Load Text to describe the library load for the point of connection.

Description Tab

Figure 2: Description Tab

Load Data

Option Description
Load Model Select from Specified (user-entered) data or from SCADA (Supervisory Control and Data Acquisition) data. SCADA data can be imported by clicking File > Import.
FLA Full load amps (rated continuous current) of the load. The point of connection load is treated as a constant kVA load model when performing power flow calculations.
PF Power factor for the load.
Scaling Factor Each load can be varied by applying a different scaling factor. This lets you model the actual panel or lumped load on a bus, then study different loading conditions. This allows quick “what if” studies and prevents errors that occur from data entry.
Demand Factor Demand factor for the load.
Protective Device

The protective device information comes from the breaker located between the point of connection and the bus.

Conductor

The conductor information comes from the cable that joins the point of connection with the bus.

Harmonics Tab

Use the Harmonics tab to indicate whether this equipment item is introducing harmonics into your power system.

Figure 3: Harmonics Tab

Option Description
Load Type

The default is Linear, indicating the equipment does not produce harmonics. Choosing Harmonic makes the item an harmonic source and makes other fields in this tab available to edit.

Note: For an adjustable frequency drive (AFD), the Load Type is always Harmonic.
For motors, the Load Type is Harmonic if the With Adjustable Frequency Drive (AFD) check box is selected on the Specifications tab of the motor; otherwise, it is always Linear.

Fundamental Amps

Use to set the fundamental amps. The options are as follows:

  • Equipment Rating sets Fundm Amps to the equipment rating of the item described in the Specifications tab. 
  • User Specified activates the Fundm Amps field, enabling you to specify a value. 

To use fundamental current calculated by power flow, select Calculated from Power Flow in the Summation Fundamental Voltage area of the Harmonics Options > Control dialog box.

Harmonic Spreadsheet

Use the spreadsheet to enter the harmonic spectrum produced by this item. You can enter up to 30 different harmonics in each equipment item. In the spreadsheet, enter the Harmonic Number (such as 5 for the 5th harmonic), the Harmonic Current in percent of the Fundamental Amps, and the Current Angle. By indicating the current angle, you can simulate transformer phase shift effects on rectifiers so appropriate canceling can take place. The harmonic may be integer or non-integer.

Library Load

Common harmonic spectra may be entered from the device library. For instructions on how to enter your own spectra information, see Harmonics with Spectrum™. After selecting a particular device library spectrum from the Mfr and Type lists, click Import, and that spectrum is entered into the harmonic spreadsheet.

Resistance Factor

EasyPower offers two methods for calculating RH:

  • Resistance varying with a power of the harmonic (R-EXP):
  • RH = RFund * H R-EXP

  • Resistance varying with a percent eddy current factor (%ECF):
  • RH = RFund * (1+ECF*H2)/(1+ECF)

EasyPower defaults all skin effect correction to R-EXP and a value of 0.5.

Typical Resistance Correction Factors

  R-EXP %ECF

Transformer

0.5-1.0

1.0-3.0

Utility

0.0-0.8

    -

Generator

0.3-0.6

    -

Line/Cable

0.5

    -

Reactor

0.5-1.0

0.8-3.0

Motor

0.2-0.4

    -

Arc Flash Hazard Tab

EasyPower calculates arc flash risk assessment results using the options set on the Arc Flash Hazard tab. The results are calculated for automatic transfer switches, buses, tool points of connection, MCCs, and panels.

Figure 4: Arc Flash Hazard Tab

Option Description
AF For This Bus

You can specify how you would like arc flash results determined for this bus using AF for this Bus.

Calculated: When the bus is faulted, EasyPower the performs arc flash hazard analysis using the calculation method specified in Short Circuit Options. EasyPower uses other settings on this tab as part of the calculations.

    Excluded: Select to exclude the bus from arc flash reports. An example of when you might select this option is for a bus that is required to model the electrical parameters of the system but does not actually represent a piece of electrical equipment. Other applications include nodes and tap-offs (junctions), where energized work is not required.

    Forced To: When you select this option, you can enter the incident energy and arc flash boundary for this bus. The incident energy and arc flash boundary values are shown on the one-line and in reports and work permits. This can be used for instances where you need to apply a calculation that is outside the scope of the industry standard calculations.

AF Output For This Bus

You can specify whether to display results on the line side or the load side of the Main protective device of the bus equipment. If the arc flash hazards output for this bus needs to be different from the global option, use this field. The choices are:

  • <<Use Global Option>>: Use the option specified in Short Circuit Options.
  • Including Main: Always display the arc flash hazard results on the load side of the Main protective device for this bus equipment regardless of what options are selected in the Short Circuit Options.
  • Excluding Main: Always display the arc flash hazard results on the line side of the Main protective device for this bus equipment regardless of what options are selected in the Short Circuit Options.
  • Both (Incl & Excl Main): Always display the arc flash hazard results on both the line side and the load side of the Main protective device for this bus equipment regardless of what options are selected in the Short Circuit Options.
Trip Times for this Bus

You can select the method for determining trip times for this bus by choosing from the following:

  • Pre-defined Fixed Times: Obtains arc clearing time for the bus from the library default values. This is not the same as the trip times calculated form the TCC curves of the upstream trip device. The values stored in the library are simply predefined approximate trip times. This is a legacy method and is not recommended.
  • User-defined Times: With this option you can specify the protective device clearing time for each bus. The details of arcing time for the bus can be specified in the fields Device ID, Relay Function and Time (s). When this option is selected, a time must be specified.
  • TCC Times (Automatically Calculated): Arc flash incident energy are calculated based on time characteristic current curves specified in each protective device data dialog box. The trip clearing time of the equipment where the device is a relay controlled breaker is the sum of the breaker mechanism opening time (for example, 3, 5, or 8 cycle), the relay trip time, and any time entered into the Relay Data, System, and Aux Time data fields.
  • User-defined and TCC Times: Provides results for both user-defined times and TCC times as described above.
  • User-defined One-line Device: With this option, you can specify which device you want to use for the TCC time, and the program will obtain the trip time automatically. You can select a device type (relay fuse, or low voltage breaker) and device ID. If you select a relay, you also select the relay function.

Note: When a user-defined time is specified and the calculation method is set to use the integrated method, only the upstream device setting is used. The time is considered as the maximum length of the simulation. See The Integrated Method for more information.

Working Distances

You can specify the working distances shown on the one-line and in reports and work permits.

  • Default from Options: When selected, the program uses the workings distances from the Default Working Distances spreadsheet in the Arc Flash Hazard Options.
  • User Specified: Selecting this option enables you to enter the working distance for this item.

The units displayed are based on the units selected in Arc Flash Hazard Options on the System tab. For inches, the range is 1-1000. For meters, the range is 0.1 to 1000.

Electrode Gap

You can specify the electrode gap shown on the one-line and in reports and work permits.

  • Default from Library: When selected, the program uses the electrode gap from the device library.
  • User Specified: Selecting this option enables you to enter the electrode gap for this item. The range is between 0.1 and 25,000 mm.

Electrode Configuration

You can specify the electrode configuration shown on the one-line and in reports and work permits.

  • Default from Library: When selected, the program uses the electrode configuration from the device library.
  • User Specified: Selecting this option enables you to select the electrode configuration for this item. The options available are based on the orientation of the electrodes, whether they are inside an enclosure, and in one instance, whether they terminate into a barrier.
  • Electrodes in Enclosures:

    • VCB: Vertical electrodes inside an enclosure.
    • VCBB: Vertical electrodes terminating in an insulating barrier inside an enclosure.
    • HCB: Horizontal electrodes inside an enclosure.

    Electrodes in Open Air:

    • VOA: Vertical electrodes in open air.
    • HOA: Horizontal electrodes in open air.

You can select more than one configuration to represent the multiple types of conditions that can occur for the equipment. EasyPower evaluates each configuration and then provides values for the highest incident energy based on the existing electrode configurations. Annex C in the IEEE 1584-2018 standard describes examples where you might use more than one electrode configuration.

Tip: To change the electrode configuration for multiple items on the one-line, select the items in the Database Edit focus and then on the Home tab, click Change > AF Bus Electrode Configuration.

Electrode configurations are only applicable to the IEEE 1584-2018 standard. For more information, see Electrode Configuration.

Enclosure Size

You can specify the enclosure size shown on the one-line and in reports and work permits.

  • Default from Library: When selected, the program uses the enclosure size from the device library. The library provides typical values based on the equipment type and voltage.
  • User Specified: Selecting this option enables you to enter the enclosure size for the item. This enables you to get more accurate calculation results, assuming the correct dimensions are entered.
  • The units displayed are based on the units selected in Arc Flash Hazard Options on the System tab. For inches, the range is .01-1000. For millimeters, the range is 0.1 to 25,000.

The enclosure dimensions affect arc flash.

  • Arc flash is greatest for a 20 in. x 20 in. x 20 in. enclosure.
  • Arc flash decreases as the height or width dimensions increase.
  • In low voltage equipment with a height and width of less than 20 inches, arc flash decreases if the depth dimension is less than or equal to 8 inches.
Labels to Print

Enter the number of labels you want to print for arc flash hazard analysis. If you enter "0," no labels will print.

Comment

You can type a comment that appears on the arc flash label when it is printed. For example, you could type a location description for the equipment to assist with label placement.

Other Tabs

See Common Tabs for information on the Location, Reliability, Comments, Hyperlinks, Media Gallery, or Collected Data tabs.

More Information

Database Technical Reference Common Tabs
Edit Tools Electrode Configuration
Media Gallery