Motor Control Center (MCC) Data

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: MCC Data Dialog Box

Connection Information

Option Description
ID Name

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 MCCs, the program automatically assigns the names MCC-1, MCC-2, MCC-3, and so on.

Base kV The base kV of the MCC. MCC’s are modeled like a bus in many ways. You can connect cables, busways or transformers to it, and perform fault calculations.
Spreadsheet View and Configure See Configuring the Spreadsheet View for information about these options.
Lock Auto-Sizing When this check box is selected, this item cannot be automatically sized using SmartDesign™ (the auto-design feature).

Specifications Tab

These are the specifications for the MCC including the bus.

Option Description
Service Select the service for the MCC. Your options are 3 Phase-3 Wire or 3 Phase-4 Wire.
Unit Select either U.S., Metric, or CSA.

Bus Rating

These are all user-defined fields.

Mfr Use this text field to describe the MCC manufacturer.
Type Use this text field to further describe the MCC manufacturer model.
Bus SC Rating (kA) The rating of the bus used in calculating the Short Circuit duties for SmartDuty™.
Horz Bus Rating (A) The current rating of the horizontal bus.
Vert Bus Rating (A) The current rating of the vertical bus.
Bus Data
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 Use this text field to describe the particular MCC.
Device Code You can type letters or numbers to describe the device code for the equipment item. The information can be converted and printed as a QR code on arc flash labels.
Fed By Use this field to indicate the transformer or the power supply source feeding the MCC.
Last Updated The date and time the MCC data was last updated is displayed here.
Header Comment Use this field for any comment on the MCC.

Incoming Tab

Figure 2: Incoming Tab

Option Description
Incoming Device Type

You can select the type of incoming protective device type for the MCC. The choices available are:

  • Main Lug Only: No protective device is present.
  • Main Breaker: An LV breaker protects the MCC bus. Select the breaker using Incoming Device Settings.
  • Main Fuse: A fuse protects the MCC bus. Select the fuse using Incoming Device Settings.
Incoming Branch Select the incoming branch equipment such as cables, transformers or busways. All the branches connected to the MCC in the one-line are displayed.
Incoming Device Settings Opens the data dialog for the main fuse or main breaker specified as the incoming device type. See Low Voltage Breaker Data or Fused Switch Data for more information.

Description Tab

This is a spreadsheet listing similar to the Device Library. When you place a new MCC on the one-line, the first time you open its database dialog and click on the Description tab, EasyPower displays the MCC Spreadsheet Creation Wizard which enables you to select the number of rows you want. Clear the check box at the bottom of the Wizard dialog if you don't want it to appear with each new MCC. You can insert or append new rows in the spreadsheet if you need them later.

Figure 3: MCC Spreadsheet Creation Wizard Dialog Box

Figure 4: Description Tab of MCC Data Dialog Box

When you click on the Description tab, additional buttons become available on the toolbar. These enable you to perform actions related to the spreadsheet. See Additional MCC and Panel Spreadsheet Options for more information.

Option Description
MCC Library

The list contains all of the same schedules as the Device Library. To enter a listing other than those contained in the list, create a new page in the MCC section of the Device Library. See EasyPower Device Library for more information.
Schedule This list enables you to specify which Device Library Schedule your chosen Library Load spreadsheet is located in. To enter a listing other than those contained in the list, create a new page in the MCC section of the Device Library. See EasyPower Device Library for more information.
Export The spreadsheets can be exported to metafiles (.WMF) or delimited database text files (.CSV). Export is beside the Print button on the MCC/Panel dialog box toolbar when the viewing the Description tab.

Spreadsheet

Note: The Section Space and Equipment Name are not necessary for calculation purposes but are used to match the way they are organized in the MCC.

Option Description
Section Space Enter the location of the individual bucket in the MCC. Typical entries would be 1A, 1B, 2A, 2B, 2C, and so on.
Equipment Name Enables you to identify each piece of equipment.
Library Load This list corresponds directly to the Library Load column in the Device Library. After you have made selections in the MCC Library, Schedule and Library Load fields, all of the data cells that follow are automatically filled in when you click on another cell. You can also double-click on the cell to enter something different than what is listed.
Status The third column is a toggle "On/Off" to indicate if this particular item is currently connected to the MCC schedule. This affects the power flow and short circuit current contribution.
Load Type

You can select different kinds of loads such as motors, loads, or sub-MCC/panel. Based on the load type selected, various analysis are possible. When you select a load type, the cells in the row that do not apply become unavailable. You might see a Data button indicating you need to enter data specific to the load type. Cells highlighted in red require data in order to perform any analysis. The following load types are available:

  • Motor: The motor data required for analysis are usually Motor HP (U.S., CSA) or kW (metric), Motor X/R, and the X/R Ratio in the Short Circuit tab. The required data fields are highlighted in red. If you do not know the motor X/R ratio, you can calculate typical X/R ratio for the motor based on size by selecting the cell for Motor X/R and clicking Calculate in the toolbar or by pressing F9 on the keyboard. A motor contributes to the short circuit current. You can enter other data in the row, such as cable description, protective device, starter description and capacitor data. When you select Motor as a load type, you can plot its curves on the TCC plot.

    • Note: Motor FLA for 3-phase motors is calculated as follows. For U.S. units, the NEC table FLA values are used. For metric units, motor FLA is calculated as Motor kW/(Motor Eff * Motor power factor * Equipment kV * SQRT3).

  • Load: The load data is entered in the columns Static kW and Static kVAR. Other data entries are optional. You cannot plot curves for devices in the TCC plot.

  • VFD (non-regen): Non-regenerative variable frequency drive. The motor data required for analysis are usually Motor HP (U.S., CSA) or kW (metric), Motor X/R, and the X/R Ratio in the Short Circuit tab. The required data fields are highlighted in red. If you do not know the motor X/R ratio, you can calculate typical X/R ratio for the motor based on size by selecting the cell for Motor X/R and clicking Calculate in the toolbar or by pressing F9 on the keyboard. You can enter other data in the row, such as cable description, protective device, starter description and capacitor data. When you select VFD as a load type, you can plot its curves on the TCC plot.

  • Sub-MCC: This means the current MCC is feeding another MCC. You need to specify the sub-MCC ID name and the cable connecting the two MCCs. You also need to enter the protective device data for the sub-MCC. You can plot the protective device curve on a TCC.
  • Sub-Panel: This is similar to a sub-MCC type, except it is used when connecting the MCC to a sub-panel.
  • Motor w/ TCC: The load type is motor. However, you can plot the cable damage curve, protective device trip curve and the motor starting curve on a TCC plot. You need to specify the motor data, protective device data and the cable data.
  • Load w/ TCC: You can plot the curves for cable and protective device on a TCC plot. The load is specified in kW and kVARs.
  • VFD w/ TCC: The load type is motor with a variable frequency drive (VFD). However, you can plot the cable damage curve, protective device trip curve and the motor starting curve on a TCC plot. You need to specify the motor data, protective device data and the cable data.
  • <50 HP Lump: This is to model a group of motors all of which are under 50 HP rating. No TCC plot is obtained for this type of load.
  • >50 HP Lump: This is to model a group of motors all of which are larger than 50 HP rating. No TCC plot is obtained for this type of load.
  • <37 kW Group (metric only): This is to model a group of motors all of which are under a 37 kW rating. No TCC plot is obtained for this type of load.
  • >37 kW Group (metric only): This is to model a group of motors all of which are larger than a 37 kW rating. No TCC plot is obtained for this type of load.

The rest of the fields correspond directly to those in the Device Library. See EasyPower Device Library for more information.

For more information on the MCC spreadsheet, see the following topics:

Summary Tab

The Summary tab of MCC Data dialog box provides the total load on the MCC and the load that must be used in designing.

Figure 5: Summary tab of MCC Data Dialog Box (U.S. Units)

Figure 6: Summary tab of MCC Data Dialog Box (Metric Units)

Option Description
Calculate Downstream Load Calculates the total load on the MCC, taking into account the connected load, demand factors, and NEC code factors.
Override with User Values This check box enables you to enter data in the Total Downstream Load – kVA column.

Spreadsheet

The spreadsheet has two sections – MCC Load and Including Downstream Load.

Option Description

MCC Load

This spreadsheet section provides the summary of the loads fed by the feeders of the MCC. The loads from the sub-MCC and sub-panels are not included in this section.

Total kVA This is the aggregate load.
Total FLA Total load in amps.
Motor HP The total HP for the items with "On" in the Status column of the Description section.

Motor kVA >= 50 HP

Motor kVA >= 37 kW

 The total KVA for connected items equal to or greater than 50HP (U.S. units) or 37 kW (metric units).

Motor kVA < 50 HP

Motor kVA < 37 kW

 The total KVA for connected items greater than 50HP (U.S. units) or 37 kW (metric units).

VFD HP or kW

Variable frequency drive HP (U.S. units) or kW (metric units).
Static kVA Total kVA of the loads.
Capacitor kVAR Total kVARs of all the capacitors
(Calculations)
Connected Connected kVA = [(SkW)2 + (SkVAR)2]1/2
Demand

Demand kVA = [S(kW * DF)2 + S(kVAR * DF)2] ½

Where DF is the individual demand factor of each MCC circuit.
Code Factors

Code Factors kVA = [(kWL + SkW)2 + (kVARL + SkVAR)2]1/2

Where, kWL = Code Mult Factor * kW for largest motor in MCC.

KVARL = Code Mult Factor * kVAR for largest motor in MCC.

kW and kVAR are for the rest of the loads.

The code multiplying factor is specified in Tools > Options > Equipment.
Design

Design kVA = Code Factors kVA * Design Factor

The Design Factor is specified in Tools > Options > Equipment.

Including Downstream Load

This provides the sum of the loads fed by feeders inside the MCC and the sub-MCC and sub-panels.

kVA Total kVA load calculated. You can enter your own values in these fields by selecting the check box for Override with User Values.
FLA Total FLA load calculated. You can enter your own values in these fields by selecting the check box for Override with User Values.

Short Circuit Tab

Figure 7: Short Circuit Tab of MCC Data Dialog Box (U.S.)

Figure 8: Short Circuit Tab of MCC Data Dialog Box (Metric)

Option Description

kVA >50Hp

kVA >37kW

 Total kVA of the motors which are greater than 50Hp (U.S. units) or 37kW (metric units).
X"dv or Xlr Is set at the default value for >50Hp (U.S. units) or 37kW (metric units). You can enter your own value and it applies to all the motors greater than 50Hp or 37kW.
X/R Avg Calculate fills this field using values from the spreadsheet. You can enter your own X/R average.

KVA <50Hp

kVA >37kW

 Total kVA of the motors which are less than 50Hp (U.S. units) or 37kW (metric units).
X"dx or Xlr Is set at the default value for <50Hp (U.S. units) or 37 kW (metric units) but you can change this. You can enter your own value and it applies to all the motors less than 50Hp or 37kW.
X/R Avg Calculate fills this field using values from the spreadsheet. You may enter your own X/R average.
Calculate Click to calculate the X/R averages for motors greater than and less than 50Hp (U.S units) or 37kW (metric units).

Power Flow Tab

Figure 9: Power Flow Tab of MCC Data Dialog Box

Option Description
Load Model Enables you to select the motor kVA from the MCC Specifications data or from SCADA (Supervisory Control and Data Acquisition) data. SCADA data can be read in by clicking File > Import.
MCC Specifications

kVA: Select the method used to determine the kilovolt-ampere for power flow analysis. Choose between:

  • Connected: The kVA is determined by the load defined on the Description tab of the MCC.
  • Demand: The kVA is determined by the demand factor. Demand factor is calculated as the maximum loading conditions divided by the total connected load. This is specified on the Description tab of the MCC.
  • Code: The kVA is determined by the code factors. Code factors are derived from the factors set up in the database File Properties on the Code Factors tab which reference NFPA 70 (NEC) article 220.40. You can view or edit the codes on the Description tab of the MCC.
  • Design: The kVA is determined by the design factor in combination with the code factors. Design factor is set up in Tools > Options on the Equipment tab. You can view or edit the design factor on the Description tab of the MCC.
Load Type

Motors can be modeled for the power flow solution in several different ways.

  • Constant kVA - This is the most common model. It is conservative, and results in slightly lower voltage values than would be measured on an actual system.
  • Constant Current - This model is generally not used in motor modeling. It more closely matches an induction motor's characteristics in the reactive component than other models, but is technically incorrect because kW is relatively constant throughout the voltage range for an induction motor.
  • Constant Impedance - This model is used for starting induction and synchronous machines, and closely matches motor characteristics during low voltages.
  • kW + j Current - This model is a combination of the above models and more closely matches actual motor characteristics within normal operating voltages.
Scaling Factor Provides an easy way of adjusting the total motor load used in determining power flows. By changing the scaling factor, the actual Hp (total connected value) entered in the Hp field can remain static. This reduces modeling errors and eliminates multiple databases for different contingencies.

SCADA Model

SCADA data is derived from real time, or metered data, and converted to an ASCII format which can be read into EasyPower. SCADA data is read in as a 100% scaling factor load. The load value is multiplied by the user-defined scaling factor. This provides a way to adjust SCADA loads to form new cases.

kW The kW value as read in from the SCADA ASCII file.
kVAR The kVAR value as read in from the SCADA ASCII file.
Load Type

SCADA data can be modeled in the power flow solution in several different ways. SCADA load type is set in the ASCII file, but can be changed by you.

  • Constant kVA - This is the most common model. It is conservative, and results in slightly lower voltage values than would be measured on an actual system.
  • Constant Current - This model is generally not used in motor modeling. It more closely matches an induction motor's characteristics in the reactive component than other models, but is technically incorrect because kW is relatively constant throughout the voltage range for an induction motor.
  • Constant Impedance - This model is used for starting induction and synchronous machines, and closely matches motor characteristics during low voltages.
  • kW + j Current - This model is a combination of the above models and more closely matches actual motor characteristics within normal operating voltages.
Scaling Factor Provides an easy way of adjusting the total SCADA load used in determining power flows. By changing the scaling factor, the actual kW +j kVAR read in from the ASCII file remains static, however the load used in the power flow is adjusted by this factor.

Equipment Elevation Tab

See MCC Elevation for information about this tab.

Harmonics Tab

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

Figure 10: 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 11: 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.

Accessories Tab

Figure 12: Accessories Tab

Option Description
Accessories Description The accessories for distribution equipment types can be specified in the panel, MCC, and bus dialog boxes. You can add or delete the accessory items as needed per equipment. Only the selected items are displayed in the schedule outputs.
Meter Data
Note An accessory note of up to 1,024 characters.
Maximum Demand The maximum demand load at this equipment.
Power Factor The power factor for the equipment.
Reading Date The date the meter was read or the information was gathered.
kVA
Safety Factor Percentage above the kVA that will be multiplied to calculate the new safety factor load.
Load with Safety Factor Load amount after calculating the safety factor.
Added (New) Demand Load User-specified load amount to add to the equipment.
Total New Demand Load Total of the load with safety factor and the added demand load.
Total Amps Amps based on the total demand load.

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
Media Gallery MCC Spreadsheet Notes

Configuring the Spreadsheet View

Electrode Configuration