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TABLE OF CONTENTS
UL 508A DESIGN CALCULATORS
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DATE
VERSION
UL 508A CONDUCTORS
                     
SHOW              
  CONDUCTOR SIZE WITHIN A UL 508A PANEL:            
Insulated conductors (wires) within a UL 508A panel must be copper and must have 90 deg C insulation but be rated according to either 60 or 75 deg C insulation level amp values in order not to exceed this internal terminal maximum temperature limit requirement.
40 deg C surrounding air ambient is that matching the UL 508A panel high temperature rating. UL 508A does not use temperature rating factors. 		   
Note: This "General" calculator allows you to input a current (amps) that you have derived by your own means. You can use the BRANCH-FEEDER RATINGS TAB (higher level tab within this same application - which will calculate, combined into a single calculator,  all conductor ratings and sizes directly, as well as the protection components (fuses and breakers), based on your guided inputs of loading details.   ``
CONDUCTOR CURRENT REQUIRED:        AMPS    
PANEL TEMPERATURE (CENTIGRADE):     40   DEG C    
All terminals including device terminals in this particular power circuit.

 TERMINAL TEMPERATURE MINIMUM:
DEG C    
CONDUCTOR FOR THE CURRENT:                  
Include conductors for this circuit plus others of other power circuits in the same bundle. Example: If you have a three phase power set for this feed ran in the same bundle as 5 other power conductors, then the total should be 8 (7 - 24 range). Any neutrals are not counted.
(Do not run control wires with power conductors).
 TOTAL NUMBER OF CONDUCTORS IN A BUNDLE:
   
     
CORE SIZE REQUIRED AS BUNDLED:            
PARALLELED CONDUCTORS FOR THE CURRENT:                
Include conductors for this circuit plus others of other power circuits in the same bundle. Example: If you have a three phase power set using 4 paralleled cable per phase for this feed ran in the same bundle as 5 other power conductors, then the total is should be 17 (7 - 24 range). Any neutrals are not counted.
(Do not run control wires with power conductors). TOTAL NUMBER OF CONDUCTORS IN A BUNDLE:
   
   
TOTAL CORES AND SIZE REQUIRED:          
   
                   
SHOW              
  CONDUCTOR SIZE OUTSIDE A UL 508A PANEL PER NFPA/NEC:        
Insulated conductors (wires) outside a UL 508A panel given here are based on copper (which should be used in Industrial Machinery) conductors with a range of insulation temperature ratings (here 60, 75, 90 deg C most commonly) and are rated accordingly.
Conductors outside a UL 508A panel are rated at the surrounding air ambient that you select stipulated or determined by the overall machine or plant supply system requirements and conditions.
You are also asked to select a terminal temperature so as not to exceed a particular maximum rating at any particular connection point (such as the UL 508A panel which would have at least 60 Deg C - more generally 75 Deg C - rated but possibly not more).
You are also asked to select the number of cores in the group, starting with between 1 and 3. (Single, each running separated from each other, core ratings - which are about 50% higher are not recommended nor given here at this time due to the practical difficulty in defining and  maintaining adequate separation of the more typical 3 cores or pairs forming a power circuit). 		   
CONDUCTOR CURRENT REQUIRED:               
          AMPS    
COPPER CABLE YOU ARE USING: INSULATION RATING:          
         
DEG C    
          DEG F    
SURROUNDING AIR TEMPERATURE MAXIMUM:              
     
DEG C    
          DEG F    
LOWEST TERMINAL TEMPERATURE RATING FROM ALL CONNECTION POINTS:          
     
DEG C    
          DEG F    
Include conductors for this circuit plus others of other power circuits in the same bundle. Example: If you have a three phase power set for this feed ran in the same bundle as 5 other power conductors, then the total should be 8 (7 - 24 range). Any neutrals are not counted.
(Do not run control wires with power conductors).
 TOTAL NUMBER OF CONDUCTORS IN A BUNDLE:
             
         
     
One conductor carrying the full current required - in a group (bundle) with others carrying that same current. CONDUCTOR FOR THE CURRENT:
         
PARALLELED CONDUCTORS UNDER CONSIDERATION - PLEASE CHECK BACK          
                     
                     
SHOW              
  CONVERSIONS: AMERICAN WIRE GAUGES AND SQ.MM. (BOTH WAYS)        
THE FOLLOWING LOOK-UPS GIVE THE  CLOSE OR NEXT HIGHER SIZE    
AWG OR KCMIL GAUGE:      
   
CLOSE OR NEXT HIGHER METRIC:       SQ.MM.    
           
METRIC SIZE:        
SQ.MM.    
CLOSE OR NEXT HIGHER USA SIZE:      
                   
UL 508A SPACING
                           
   
Derived from UL 508A 10.
10.1 Other than as required by
9.2, (live screw heads)
9.4, (mounting - rotation)
10.8, (Fuse Holder) see PDUSA note
12.1, Measuring
13.2, Insulating Materials
exception to
21.3.4, Construction - guards
28.2.1(a),Components
28.2.2(a), Pressure Connectors
29.2.2(a), Bus bars
29.3.6, Multiple Conductors
29.3.8, Splices
36.2.2, Resistors
spacings at and within a component or device shall be investigated
based on the requirements for that component or device SPACING OF LIVE TERMINALS FROM EACH OTHER AND METAL
PDUSA does not directly apply the potentially reduced requirement for fuse holders in this tool. (UL508A 10.8). If you take 10.8 to mean that you can select "BRANCH" and "General" as so have some smaller spacings in the feeder , then you may.
PDUSA note
?
PDUSA recommends that the input terminals to a Branch Circuit Protector to (still ) be considered as part of the feeder region (there may be contradictions between sections of Standards currently)
 ?
 
POWER LEVEL REGION OF PANEL notes:
Branch region includes all power terminals from the output of the BCP (OCPD, SCPD) to the panel output terminals.
Feeder Region includes all power terminals from the input terminals (PDUSA still recommends their inclusion) of each BCP and upstream distribution.
See the Fig.1 link here to the right of this note for further definition.
(Choose Feeder if unsure to give most conservative spacings) ?
Fig.1    
 
     
RATING LEVEL OF DEVICE notes:
Devices having limited ratings: Defined as:
see UL 508A, 10.5
(PDUSA tool will be added to apply the criteria)
(Choose "General Industrial" if unsure, for the more conservative spacings).
 ?
     
 
      `
LIMITED RATINGS CONFIRM          
 
Confirm to allow (some) smaller spacings for live terminals that are in limited rating circuits notes:

Certain spacings (not all) between terminals of opposite polarity and to metal parts can be less for low power panels (see UL 508A 10.5)
(Check the box when sure that the live points under consideration are supplied from a source that meets the low power criteria, otherwise the slightly larger General Industrial spacings will be shown in spite of the Rating Level selection) ?
 
VOLTAGE RMS OR DC (V)          
 
     
FIELD TERMINAL OVERRIDE          
 
Allow (some) smaller spacings for live terminals that are NOT used as field terminals notes

Certain spacings (not all) between terminals of opposite polarity and to metal parts will be more if the terminals are used for field connections in consideration of projecting strands. (see UL 508A Table 10.1 note b.)
(Check the box when sure that the live points under consideration have only factory made and inspected connections made to them) ?
 
  Between any uninsulated:
- live part and another of other polarity
- or other internal grounded metal
- (larger spacings to walls - see below) 		 
  THOUGH AIR OR OIL            
  LIVE     LIVE OPPOSITE OR LOWER VOLTAGE  
                     
    EXPOSED METAL INTERNAL      
                     
                     
  OVER SURFACE notes:
Slots, grooves, or similar gaps including air of 0.013" (0.33mm) or less are disregarded in the measurement over the surface.
 ?
       
  LIVE     LIVE OPPOSITE OR LOWER VOLTAGE  
                     
  INSULATOR OR COMPONENT SURFACE        
    EXPOSED METAL INTERNAL      
                     
  INSULATOR OR COMPONENT SURFACE        
                     
  SPACINGS TO WALLS            
  Between any uninsulated live part:
- and the walls of a metal enclosure
- (including conduit hubs in the wall)
- (including armored cable entering) 		 
  LIVE     CABINET WALL          
        OR            
               
                     
      CONDUIT FITTING OR ARMOURED CABLE IN THE WALL          
               
     
UL 508A AC MOTOR CURRENTS
                   
SHOW            
 
This "flc" (full load current) is the "standard" current to be used for the sizing of short circuit protection and conductors. It is invariably higher than the "fla" (full load amps) nameplate value on the actual motor. The latter is to be used for sizing and settings on load components such as the overload trip relay.
 AC MOTORS: "UL 508A STANDARD FULL LOAD CURRENT" VALUES
     
THESE VALUES ARE THOSE TO BE USED IN THE SELECTION OF SHORT CIRCUIT PROTECTION DEVICES BEFORE, AND CONDUCTORS IN, THEIR BRANCH CIRCUIT. (AS APPOSED TO ACTUAL NAMEPLATE FULL LOAD AMPS WHICH ARE TO BE USED FOR THEIR OVERLOAD PROTECTION, AND OTHER LOAD CONTROL COMPONENTS).  
                 
THREE PHASE:              
  MOTOR VOLTAGE:  
VOLTS  
  MOTOR HP:(dial)    
  MOTOR HP:(entered)   HP  
  KW CONVERSION OF ENTERED HP:   KW  
 
This "flc" (full load current) is the "standard" current to be used for the sizing of short circuit protection and conductors. It is invariably higher than the "fla" (full load amps) nameplate value on the actual motor. The latter is to be used for sizing and settings on load components such as the overload trip relay.
 FULL LOAD CURRENT:
    AMPS  
           
SINGLE PHASE:              
  MOTOR VOLTAGE:  
VOLTS  
  MOTOR HP:(dial)    
  MOTOR HP:(entered)   HP  
  KW CONVERSION OF ENTERED HP:   KW  
 
This "flc" (full load current) is the "standard" current to be used for the sizing of short circuit protection and conductors. It is invariably higher than the "fla" (full load amps) nameplate value on the actual motor. The latter is to be used for sizing and settings on load components such as the overload trip relay.
 FULL LOAD CURRENT:
    AMPS  
                 
UL 508A BRANCHES_FUSE-BREAKERS
                   
SHOW              
  BRANCH CIRCUIT: PROTECTOR (BREAKER OR FUSE) AND CONDUCTORS        
This simplified version handles a single branch protector and the load or loads under it. All conductors are calculated and sized.( Please reselect, clear or write over any example entries - entries are yellow filled  )
 (The INTEGRATED  "UL 508A COMPLETE NETWORK SIZING" (other tab) combines all tools and applies the same calculations for all branches and all loads, and allows calculations of feeder circuits above them).
1. PLEASE SELECT VOLTAGES FOR ANY MOTORS (AND WINDINGS) DIRECTLY STARTED AND RAN FROM AC LINES
    
3 PHASE   BRANCH CIRCUIT PROTECTOR (from below)
1 PHASE  
The actual BCP type with its rating is selected in the "BRANCH" calculator above.
(if you have not selected a particular one then the maximum rating is used as worst case for the most conservative conductor sizing)


 BCP
Shown below are the (less than full rated to the BCP size) ratings and sizes that could be used within the panel where tapped from the BCP to carry only a smaller current for their particular load, and based upon the terminal temperature selection under the full branch conductor calculation.
  AC MOTOR OTHER LOADS NUMBER GROUPED
  3PH  1PH   HEATER OTHER SOLID STATE
LOAD # HP fla(c) amps amps
This less than full rating value may be used as a "tap". Rating shown the larger of 1.25 x load amps, 1/3rd BCP rating.

 TAP RATING (AMPS)
Minimum gauge is that required for amps with derating for group, with a absolute minimum of 14 AWG.
AWG to 230 amps
KCMIL over 230 amps
 MIN. GAUGE (AWG)
1
2
3
4
5
6
7
8
                   
SUMMARY FROM LOAD MAP OF BRANCH LOAD TOTAL(S)    
MAX LINE MOTOR AMPS    
SUM OF REST OF LINE MOTORS AMPS    
SUM OF HEATERS . AMPS    
SUM OF OTHER LOADS . AMPS    
SUM OF SOLID STATE LOADS . AMPS    
BRANCH (SHORT) CIRCUIT PROTECTOR "BCP" CALCULATION:    
PROTECTOR RATINGS PER UL 508A and NEC   MIN MAX      
  TIME DELAY FUSE     AMPS    
or            
  INVERSE TIME BREAKER     AMPS    
SELECTION
AMPS    
BRANCH CONDUCTOR RATING AND SIZE CALCULATION:    
(FOR GROUPED LOADS SMALLER TAPS MAY BE ALLOWED INSIDE THE PANEL - see left side of Load Map above) FULLY RATED CONDUCTOR FOR BRANCH CIRCUIT IS 
AMPS    
SINGLE CONDUCTOR FOR THE CURRENT:    
INTERNAL PANEL TEMPERATURE (CENTIGRADE): 40 C    
TERMINAL TEMPERATURE MINIMUM:
   
TOTAL NUMBER OF CONDUCTORS IN A BUNDLE:
   
SINGLE CORE SIZE REQUIRED: FEED IN TO BRANCH AND COMMON BEFORE TAPS. SEE RIGHT SIDE OF LOAD MAP ABOVE FOR SMALLER SIZED TAPS    
UL 508A COMPLETE NETWORK SIZING
SHOW - HIDE OVERVIEW GUIDELINES                                
I. Branch Circuits are those devices and conductors within a panel immediately before the output terminals connecting them to their external loads.
These devices have two functions:
1. COMPONENTS SIZED FOR THE LOAD:
To provide isolation, control, and overload protection (as required), tailored to their particular load (typically a combination of one or more disconnects, switches, contactors, overload relays, and solid state devices such as drive controllers).
2. A PROTECTOR FOR THE COMPONENTS AND CONDUCTORS AGAINST SHORT CIRCUITS:
To connect those same devices of "1" to the feed supply (panel power distribution above) in order to provide short circuit protection for these panel mounted  devices themselves in the event of high currents should a short circuit fault occur in the branch-load circuit internally or externally.

The latter function "2" must be done using a "Branch Circuit Protector" (BCP), also called "OCPD" or "SCPD" (Overcurrent or Short Circuit Protection Device). A device used as a BCP must meet and be listed under particular UL component standards. Their sizing must also comply with Industrial Control Panel Safety Standard UL 508A. (In the case of solid state devices, the manufacturer will usually stipulate the BCP required or it may be built into the controller itself, but if not, then this calculator may be used).  		         
II. Devices most commonly used in an industrial control panel as BCP(OCPD)(SCPD) are Time Delay Fuses (UL 248) (sets), Inverse Time Circuit Breakers (UL 489). This application concentrates on those two types of devices because they can be applied more generally (e.g. as protectors to both single and grouped branch circuits under one where required), and particularly because their sizing must comply with specific criteria which this calculator applies for you.
This application applies the rules of UL 508A based upon your entries of HP for motors and amps for other loads to give the size of the BCP(OCPD)(SCPD) in amps and the conductors that may be used in amps and gauge. 		         
III. Combination Motor Starters are also used in branch circuits and combine the short circuit protection BCP(OCPD)(SCPD), disconnect, control and overload function into a single UL assessed device. They are intended and should be used only with a single motor load. This application is not needed for the combination motor starter as its sizing is determined directly from the FLC amps (UL508A , Table 50.1) for the HP of the motor and its overload setting from the actual motor's nameplate amps and overload allowed. These FLC amp values (per the Standard - not the nameplate) are the ones used throughout this application.
(You can use the LOAD MAP to look up the amps to use for any motor - just choose any empty row and enter the HP - or use the UL 508A AC MOTOR CURRENTS tab here) 		         
IV. Often it is an advantage (cost of components, assembly, wiring), and good design to connect the individual disconnect, control, overload, conductors of several branch circuits to a single BCP (OCPD)(SCPD). For example several motor circuits, with several other loads. In this case the BCP must not be bigger that the maximum stipulated for any single component under it. All components that might be suitable for "group" installation will be designated (by certification) with a maximum rating for the BCP above it. This maximum rating is normally quite high, so as long as the loads are within a reasonable range, the "group" configuration becomes a common occurrence, even where there is a range of load sizes.
It is recommended in design planning to make groups from similarly rated motors and other loads (not more that 4:1 ratio between the largest and smallest).
          
V. Feeder Circuits are those that provide power distribution to the BCPs(OCPD)(SCPD)s of the branch circuits. They will also be Fuse-Sets or Inverse Time Delay Breakers meeting the same certifications of the BCPs, although now in a different capacity (i.e. primarily for power distribution rather than short circuit protection of the circuits below them, although they may act  also to limit the level of the fault current).
Feeder devices can be arranged to provide the power to multiple BCPs (any of which itself might have one or more load circuits). Other design considerations at the direction of the panel designer  (physical size of device and conductor, logical separation of functions, short circuit level limitation, and others) will determine the number of feeder devices before the branch circuits.
This calculator allows the user to build feeder sizing accordingly using a manual entry tabulation method.
This application applies the rules of UL 508A based upon your entries to give size of the feeder device in amps and the conductors that may be used in amps and gauge. 		         
VI. All power wires within a UL 508A panel must have an insulation rating of at least 90 DEG C, but be downrated to amp values to run at 75 DEG C or even 60 DEG C maximum (so as not to exceed minimum ratings of internal terminals allowed by the Standard). (The calculators below therefore use either the 60 or 75 DEG C - as you select as you proceed with the tool - rated amp values rather than 90 DEG C conductors ratings).          
                         
1. PLEASE SELECT VOLTAGES FOR ANY MOTORS (AND WINDINGS) DIRECTLY STARTED AND RAN FROM AC LINES
          
3 PHASE          
1 PHASE          
1A. Click to Enable all calculations
                  
                         
2. PLEASE CREATE OR UPDATE "LOAD MAP"   
SHOW LOAD MAP (UNCHECK TO HIDE )  
                         
SELECTED BRANCH  
Branches are selected one by one in the "BRANCH" calculator above.
Shown on right is the one currently selected by you there.

 BR#
 
note: if you group loads then their load circuit components need to be verified as suitable for grouping under a common BCP and may carry a condition (see their specifications - or ask us sending manufacturer and part number -email below) for a certain maximum BCP size: You should ensure that your group BCP does not exceed that rating calculated in the BRANCH calculator above: Otherwise split the group into smaller ones or replace some load components with better ones.
 ENTER A BRANCH# IN THE LEFT SIDE COLUMN AND ASSIGN A LOAD TO IT BY ENTERING A SINGLE VALUE IN THAT ROW UNDER AN "AC MOTOR" (IN HORSE POWER) OR "OTHER LOADS"( IN AMPS). (you may write over the examples given or just start below them with your own BRANCH# ID). THE SAME NUMBER OR ID FOR A BRANCH MAY BE ENTERED IN MULTIPLE ROWS (SO THAT LOADS ARE GROUPED UNDER THAT SAME BRANCH PROTECTOR).
(YOU CAN THEN "CALL" ANY BRANCH, ONE AT A TIME, IN THE BRANCH CALCULATOR (3. BELOW) (USING ITS BRANCH# OR ID) WHICH WILL GIVE YOUR PROTECTOR AND CONDUCTOR SIZING).
The actual BCP type with its rating is selected in the "BRANCH" calculator above.
(if you have not selected a particular one then the maximum rating is used as worst case for the most conservative conductor sizing)


 BCP
     
Shown below are the (less than full rated to the BCP size) ratings and sizes that could be used within the panel where tapped from the BCP to carry only a smaller current for their particular load and based upon the terminal temperature selection under the full branch conductor calculation.
 
 
    AC MOTOR OTHER LOADS   NUMBER GROUPED  
UNDER   3PH  1PH   HEATER OTHER SOLID STATE
 
NOTE: Instead of a simple numeric (1,2,3 etc.) you may choose to use your own brief designation (such as a device reference like CB11, FS21 …).
You may begin in rows under the examples given (when you first load the application), or erase and write over with your own Branch#s (numbered or name as you like) and their load values.
example "1" Branch has four loads,
example "2" branch has two loads.
BRANCH#
NOTE: Instead of a simple numeric (1,2,3 etc.) you may choose to use your own brief designation (such as a load name like Lube Motor, Heater #10, …).
(You may either begin below the examples or erase and write over them). LOAD #
HP
This "flc" (full load current) is the "standard" current to be used for the sizing of short circuit protection and conductors. It is invariably higher than the "fla" (full load amps) nameplate value on the actual motor. The latter is to be used for sizing and settings on load components such as the overload trip relay.
 flc amps
amps  
This less than full rating value may be used as a "tap". Rating is the larger of 1.25 x load amps, 1/3rd BCP rating.
 TAP RATING (AMPS)
Minimum gauge is that required for amps with derating for group, with a absolute minimum of 14 AWG.
AWG to 230 amps
KCMIL over 230 amps MIN. GAUGE (AWG)(KCMIL)
 
example is shown (and below) here on first run of application.
Please write over with your own Branch # (or other name or reference) and values.
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
ADD MORE LOADS TO THE PANEL      
  3PH  1PH HEATER OTHER SOLID STATE    
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
48    
                         
                         
3. AFTER LOAD MAP IS BUILT OR UPDATED, ENTER BRANCH NUMBER HERE TO SEE RATING RESULTS          
NOTE: Instead of a simple numeric (1,2,3 etc.) you may have chosen to use your own designation (such as a device reference like CB11, FS21 …) when making the load map below.

 BRANCH #
example is shown here on first run of application.
Replace with your own Branch# (numeric or brief name) that you have used in the LOAD MAP.
                   
SHOW BRANCH AUTOMATIC CALCULATOR                                                                                                                                                                              
THE SUMMARY AUTOMATICALLY CALCULATES ENTRIES FROM THE LOAD MAP (2. ABOVE) FOR THE BRANCH# (OR DESIGNATION THAT YOU MAY HAVE CHOSEN INSTEAD OF SIMPLE NUMERIC) ENTERED, AND CALCULATES THE FUSE OR BREAKER REQUIRED AND ALL CONDUCTOR RATINGS AND SIZES.
ANY UPDATE YOU MAKE TO THE LOAD MAP ABOVE IS AUTOMATICALLY REFLECTED HERE.
(On first opening the results from BR#1(example) are shown: this calcualtor automatically replaces them with the results for your cases as you change the entry at BRANCH# ) 		   
SUMMARY FROM LOAD MAP OF SELECTED BRANCH LOAD TOTAL(S)          
MAX LINE MOTOR AMPS          
SUM OF REST OF LINE MOTORS          
SUM OF HEATERS          
SUM OF OTHER LOADS          
SUM OF SOLID STATE LOADS          
BRANCH (SHORT) CIRCUIT PROTECTOR "BCP" CALCULATION:          
RATINGS PER UL 508A and NEC   MIN
Maximum is permitted only if the minimum rated would result in a trip due to a relatively high motor starting inrush.

 MAX
           
  TIME DELAY FUSE       AMPS          
or                  
  INVERSE TIME BREAKER     AMPS          
You do not have to select a particular one here. If not, then the conductor rating will be based on the worst case (highest).
 SELECTION
AMPS          
All power wires within a UL 508A panel must have an insulation rating of at least 90 DEG C, but be downrated to amp values to run at 75 DEG C maximum (so as not to exceed the 75 DEG C minimum ratings of internal terminals allowed by the Standard)
 BRANCH CONDUCTOR RATING AND SIZE CALCULATION:
         
Smaller sizes may be used as taps from the BCP within the panel based on rating rules under UL 508A. These "tap" ratings and sizes are shown on the left side of the "LOAD MAP" calculated using a conservative application of the rules.
 FULLY RATED CONDUCTOR FOR BRANCH CIRCUIT IS (SEE RIGHT SIDE OF LOAD MAP FOR TAP SIZES)
AMPS          
SINGLE CONDUCTOR FOR THE CURRENT:          
Conductors in the panel are rated for a single temperature. 40 DEG C is the rating for the panel.
 INTERNAL PANEL TEMPERATURE (CENTIGRADE):
Ratings are all based on 40 degrees C which is the panel internal rating under the UL 508A standard.
C          
All terminals including device terminals in this particular power circuit.

 TERMINAL TEMPERATURE MINIMUM:
         
Include conductors for this circuit plus others of other power circuits in the same bundle. Example: If you have a three phase power set for this branch ran in the same bundle as 5 other power conductors, then the total should be 8 (7 - 24 range). Any neutrals are not counted.
(Do not run control wires with power conductors).
 TOTAL NUMBER OF CONDUCTORS IN A BUNDLE:
         
SINGLE CORE SIZE REQUIRED:          
                         
4. AFTER CREATING THE LOAD MAP (IN 1. THEN 2.) AND THE ABILITY TO TOGGLE THROUGH EACH BRANCH CIRCUIT (IN 3.), YOU MAY USE THIS MANUAL ENTRY CALCULATOR TO BUILD THE FEEDER CIRCUITS UPSTREAM OF THEM.           
NOTE: Instead of a simple numeric (1,2,3 etc.) you may choose to use your own brief designation (such as a device reference like CB1, FS5 …)
 FEEDER #
example is shown here on first run of application.
The example shows a feeder "A" feeding two branches "1" and "2".
Once you have your own branches defined in LOAD MAP, you should build and name your own feeder, writing over with and adding however as many branches you wish to feed from it.
                   
SHOW FEEDER MANUAL FILL CALCULATOR          
4. THIS IS MANUAL ENTRY: IF YOU CHANGE YOUR LOAD MAP, YOU MUST CHECK THE BRANCH(ES) ALREADY ENTERED BELOW (IN YELLOW) UNDER THIS FEEDER FOR NEW VALUES AND UPDATE THEM. (To help with your manual entries the amp values of the currently selected BRANCH (3. above) are shown (in green fill) at the top of the table below - you will see any entry that you had previously entered for that branch will turn red if they are different)          
BRANCH # BCP max line motor rest of motors   sum of heaters sum of other loads sum of solid states          
           
example is shown here on first run of application.
         
example is shown here on first run of application.
           
         
         
         
         
         
         
OTHER THAN BRANCHES
SUCH AS TO ANOTHER FEEDER OR CONTROL CIRCUIT.
 ENTER ANY OTHER CURRENTS (ACTUAL MAX CONCURRENT LOADING) SUPPLIED BY THIS SAME FEEDER NOT ALREADY INCLUDED ABOVE. 
         
         
         
         
         
MAX. MOTOR AND FULL LOADS            
ACTUAL MAX CONCURRENT LOADING              
FOR THE FEEDER CIRCUIT YOU MAY USE LESSER VALUES THAN THE ABOVE "FULL LOAD" (IN GREEN) BY WRITING IN THE "ACTUAL MAX CONCURRENT LOADING" BELOW THEM (IN YELLOW) IF YOU CAN DETERMINE SOME (COLUMN BY COLUMN) WILL BE LESS THAN THE FULL LOAD FIGURES ABOVE SHOULD NOT ALL LOADS OPERATE AT THEIR FULL RATING OR AT THE SAME TIME.
THIS ADJUSTMENT WOULD TAKE THE ADVANTAGE BY JUSTIFYING AN IMPLEMENTATION WITH SMALLER COMPONENTS AND CONDUCTORS.
THIS ADJUSTEMENT IS FROM YOUR OWN ANALYSIS OF HOW YOUR SYSTEM OPERATES (E.G. WILL SOME MOTORS WILL NEVER RUN AT FULL LOAD? - WILL LOADS OCCURR IN A DEFINTE NON-OVERALLAPPING SEQUENCE?) - AND THEN BY MANUAL ENTRY OF AN AMPS VALUE . (IT IS FIRST DEFAULTED TO 9999 AMPS (IN YELLOW BELOW) - EFFECTIVELY MEANING THAT THE FULL LOAD (IN GREEN ABOVE) WOULD THEN BE USED). (HEATER LOADS ARE TAKED AT FULL LOAD).
THE CONSERVATIVE APPROACH IS TO DO NOTHING (LEAVE ALL AT 9999) AND SO TO BASE ALL ON FULL LOADS.
 FOR THE FEEDER CIRCUIT YOU MAY USE LESSER VALUES THAN THE ABOVE "FULL LOAD" (IN GREEN) BY WRITING IN THE "ACTUAL MAX CONCURRENT LOADING" BELOW THEM (IN YELLOW) - HOVER HERE TO READ CELL NOTE.
         
FEEDER CIRCUIT WILL USE THESE AMP VALUES MAX. BCP max line motor rest of motors   sum of heaters sum of other loads sum of solid states          
           
FEEDER PROTECTOR RATING CALCULATION:           
factors            
contribution                                
REQUIRED PROTECTOR RATING:
TIME DELAY FUSE OR
INVERSE TIME BREAKER 		AMPS          
All power wires within a UL 508A panel must have an insulation rating of at least 90 DEG C, but be downrated to amp values to run at 75 DEG C maximum (so as not to exceed the 75 DEG C minimum ratings of internal terminals allowed by the Standard)
 FEEDER CONDUCTOR RATING AND SIZE CALCULATION: 
         
factors            
contribution                                
REQUIRED CONDUCTOR MINIMUM RATING:  AMPS          
Conductors in the panel are rated for a single temperature. 40 DEG C is the rating for the panel.
 INTERNAL PANEL TEMPERATURE (CENTIGRADE):
Ratings are all based on 40 degrees C which is the panel internal rating under the UL 508A standard.
C          
All terminals including device terminals in this particular power circuit.

 TERMINAL TEMPERATURE MINIMUM:
         
SINGLE CONDUCTOR FOR THE CURRENT:          
Include conductors for this circuit plus others of other power circuits in the same bundle. Example: If you have a three phase power set for this feed ran in the same bundle as 5 other power conductors, then the total should be 8 (7 - 24 range). Any neutrals are not counted.
(Do not run control wires with power conductors).
 TOTAL NUMBER OF CONDUCTORS IN A BUNDLE:
         
[0-          
PARALLELED CONDUCTORS FOR THE CURRENT:          
NUMBER PARALLELED:            
Include conductors for this circuit plus others of other power circuits in the same bundle. Example: If you have a three phase power set using 4 paralleled cable per phase for this feed ran in the same bundle as 5 other power conductors, then the total is should be 17 (7 - 24 range). Any neutrals are not counted.
(Do not run control wires with power conductors). TOTAL NUMBER OF CONDUCTORS IN A BUNDLE:
         
TOTAL CORES AND SIZE REQUIRED:           `  
         
                         
                         
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