*** BASIC DERATING EXAMPLES ***

For:
Single Phase Three Wire
And
Three Phase Four Wire
Multiwire Circuits.

02/08/2015 19:03:00 PST BY S.E.T.

PATH: D:\DESIGN_01\CAD_EDUCATIONAL01\ACAD_EDU01\ACAD_EDU\
System_Analysis_042009\DERATING\*.*
Text: \System_Analysis_042009\DERATING\DERATING_TEXT01.txt
1 PHASE 3 WIRE: \System_Analysis_042009\DERATING\X_GIF_JPG\DERATE_1PH3W01.gif
1PH. 3W. OPEN WYE: \System_Analysis_042009\DERATING\X_GIF_JPG\DERATE_1PH3W_OPENWYE.gif
3 PHASE 4 WIRE-TRANSFORMER: \System_Analysis_042009\DERATING\X_GIF_JPG\DERATING_3PH_4W_1OF2.gif
3 PHASE 4 WIRE-BUS KIT: \System_Analysis_042009\DERATING\X_GIF_JPG\DERATING_3PH_4W_2OF2.gif


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ABBREVIATIONS LIST:

1.: "CCC" = Current Carrying Conductors
2.: "CKT" = Circuit
3.: "Common G.C." = Common Grounded Conductor ("Neutral")
4.: "G.C.-2W" = Grounded Conductor of 2 Wire Circuit (Not a "Neutral")
5.: "FLA" = Full Load Amperes
6.: "L-N" = 'Line to Neutral' Two Wire Circuit
(1 Ungrounded Conductor, 1 Grounded Conductor)
7.: "L-L" = 'Line to Line' Two Wire Circuit
(2 Ungrounded Conductors, no Grounded Conductor)
8.: "L-N-L" = 'Line to Neutral to Line' Three Wire Circuit
(2 Ungrounded Conductors, 1 Grounded Conductor)
9.: "L-L-L-N" = 'Line to Line to Line to Neutral' Four Wire Circuit
(3 Ungrounded Conductors, 1 Grounded Conductor)
10.: "PF" = Power Factor
11.: "OCPD" = Overcurrent Protection Device
12.: "TBCC" = Total Branch Circuit Conductors
13.: "L0" = Grounded Circuit Conductor for 2 Wire Branch Circuit

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*** PART 1 OF 2: SINGLE PHASE THREE WIRE - CENTER-TAP ***
Source: 120/240V 1Ph. 3W Transformer (Center-Tapped 240V 1PH.)

----------Left-Side Circuits:----------

Circuits 1/3; 120/240V 1 Phase 3 Wire Multiwire Circuit (L-N-L).

Circuit #1 FLA: 7.0 Amps.
Loads:
a.: 1.0 Amp Resistive (Linear, 1.0 PF)
b.: 2.0 Amp Reactive - Inductive (Non-Linear, 0.8 PF)
c.: 4.0 Amp Reactive - Impedance (Linear, 0.98 PF)

Circuit #3 FLA: 7.0 Amps.
Loads:
a.: 1.0 Amp Resistive (Linear, 1.0 PF)
b.: 2.0 Amp Reactive - Inductive (Non-Linear, 0.8 PF)
c.: 4.0 Amp Reactive - Impedance (Linear, 0.98 PF)

Common Grounded Conductor ("Neutral") FLA: 0.0 Amps.

TBCC: (3)
Total CCC: (2)
Maximum Number of 1PH. 3W. Multiwire Branch Circuits In A Single Raceway: (4)*
*:Figures = 12 TBCC (8 CCC) using #12 THHN Cu., 20 Amp OCPD.
#12 THHN Cu. @ 90C = 30 Amps.
7-9 CCC = 0.7 Derating Factor
30.0 Amps * 0.7 = 21.0 Amps
----------------------------------------------------------------------------------------------

Circuits 5/7; 240V 1 Phase 2 Wire Circuit (L-L).

Circuit #5/7 FLA: 9.5 Amps.
Loads:
a.: 2.5 Amp Resistive (Linear, 1.0 PF)
b.: 3.0 Amp Reactive - Inductive (Non-Linear, 0.8 PF)
c.: 4.0 Amp Reactive - Impedance (Linear, 0.98 PF)

TBCC: (2)
Total CCC: (2)
Maximum Number of 1PH. 2W. Branch Circuits In A Single Raceway: (4)*
*:Figures = 8 TBCC (8 CCC) using #12 THHN Cu., 20 Amp OCPD.
#12 THHN Cu. @ 90C = 30 Amps.
7-9 CCC = 0.7 Derating Factor
30.0 Amps * 0.7 = 21.0 Amps
----------------------------------------------------------------------------------------------

----------Right-Side Circuits:----------

Circuits 2/4; 120/240V 1 Phase 3 Wire Multiwire Circuit (L-N-L).

Circuit #2 FLA: 12.0 Amps.
Loads:
a.: 2.0 Amp Resistive (Linear, 1.0 PF)
b.: 4.0 Amp Reactive - Inductive (Non-Linear, 0.8 PF)
c.: 6.0 Amp Reactive - Impedance (Linear, 0.98 PF)

Circuit #4 FLA: 18.0 Amps.
Loads:
a.: 3.0 Amp Resistive (Linear, 1.0 PF)
b.: 6.0 Amp Reactive - Inductive (Non-Linear, 0.8 PF)
c.: 9.0 Amp Reactive - Impedance (Linear, 0.98 PF)

Common Grounded Conductor ("Neutral") FLA: 6.0 Amps.
(12.0 Amps Balanced, 6.0 Amps Unbalanced)

TBCC: (3)
Total CCC: (2)
Maximum Number of 1PH. 3W. Multiwire Branch Circuits In A Single Raceway: (4)*
*:Figures = 12 TBCC (8 CCC) using #12 THHN Cu., 20 Amp OCPD.
#12 THHN Cu. @ 90C = 30 Amps.
7-9 CCC = 0.7 Derating Factor
30.0 Amps * 0.7 = 21.0 Amps
----------------------------------------------------------------------------------------------


Circuits 6/8; 2x 120V 1 Phase 2 Wire Branch Circuits (L-N).

Circuit #6 FLA: 12.0 Amps (L1 & L0).
Loads:
a.: 2.0 Amp Resistive (Linear, 1.0 PF)
b.: 4.0 Amp Reactive - Inductive (Non-Linear, 0.8 PF)
c.: 6.0 Amp Reactive - Impedance (Linear, 0.98 PF)

Circuit #8 FLA: 18.0 Amps (L2 & L0).
Loads:
a.: 3.0 Amp Resistive (Linear, 1.0 PF)
b.: 6.0 Amp Reactive - Inductive (Non-Linear, 0.8 PF)
c.: 9.0 Amp Reactive - Impedance (Linear, 0.98 PF)

No Common Grounded Conductor ("Neutral")

TBCC: Per Circuit: (2), For CKT 6/8: (4)
Total CCC: Per Circuit: (2), For CKT 6/8: (4)
Maximum Number of 1PH. 2W. Branch Circuits In A Single Raceway: (4)*
*:Figures = 8 TBCC (8 CCC) using #12 THHN Cu., 20 Amp OCPD.
#12 THHN Cu. @ 90C = 30 Amps.
7-9 CCC = 0.7 Derating Factor
30.0 Amps * 0.7 = 21.0 Amps
----------------------------------------------------------------------------------------------

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==============================================================================================







*** PART 2 OF 2: SINGLE PHASE THREE WIRE - OPEN WYE ***
Source: 120/208V 1Ph. 3W Transformer (PHASE A & B OF OPEN WYE)

----------Left-Side Circuits:----------

Circuits 1/3; 120/208V 1 Phase 3 Wire Multiwire Circuit (L-N-L).

Circuit #1 FLA: 6.0 Amps.
Loads:
a.: 6.0 Amp Resistive (Linear, 1.0 PF)
(1.0A + 2.0A + 3.0A)

Circuit #3 FLA: 9.0 Amps.
Loads:
a.: 9.0 Amp Resistive (Linear, 1.0 PF)
(2.0A + 3.0A + 4.0A)
Common Grounded Conductor ("Neutral") FLA: 8.54 Amps.

TBCC: (3)
Total CCC: (3)
Maximum Number of 1PH. 3W. Multiwire Branch Circuits In A Single Raceway: (3)*
*:Figures = 9 TBCC (9 CCC) using #12 THHN Cu., 20 Amp OCPD.
#12 THHN Cu. @ 90C = 30 Amps.
7-9 CCC = 0.7 Derating Factor
30.0 Amps * 0.7 = 21.0 Amps
----------------------------------------------------------------------------------------------

Circuits 5/7; 120/208V 1 Phase 3 Wire Multiwire Circuit (L-N-L).

Circuit #5 FLA: 10.0 Amps.
Loads:
a.: 7.0 Amp Resistive (Linear, 1.0 PF)
(3.0A + 4.0A)
b.: 3.0 Amp Reactive - Inductive (Non-Linear, 0.8 PF)

Circuit #7 FLA: 15.0 Amps.
Loads:
a.: 12.0 Amp Resistive (Linear, 1.0 PF)
b.: 3.0 Amp Reactive - Inductive (Non-Linear, 0.8 PF)
(1.0A + 2.0A)

Common Grounded Conductor ("Neutral") FLA: 13.44 Amps.

TBCC: (3)
Total CCC: (3)
Maximum Number of 1PH. 3W. Multiwire Branch Circuits In A Single Raceway: (3)*
*:Figures = 9 TBCC (9 CCC) using #12 THHN Cu., 20 Amp OCPD.
#12 THHN Cu. @ 90C = 30 Amps.
7-9 CCC = 0.7 Derating Factor
30.0 Amps * 0.7 = 21.0 Amps
----------------------------------------------------------------------------------------------


----------Right-Side Circuits:----------

Circuits 2/4; 120/208V 1 Phase 3 Wire Multiwire Circuit (L-N-L).

Circuit #2 FLA: 12.0 Amps.
Loads:
a.: 2.0 Amp Resistive (Linear, 1.0 PF)
b.: 4.0 Amp Reactive - Inductive (Non-Linear, 0.8 PF)
c.: 6.0 Amp Reactive - Impedance (Linear, 0.98 PF)

Circuit #4 FLA: 18.0 Amps.
Loads:
a.: 3.0 Amp Resistive (Linear, 1.0 PF)
b.: 6.0 Amp Reactive - Inductive (Non-Linear, 0.8 PF)
c.: 9.0 Amp Reactive - Impedance (Linear, 0.98 PF)

Common Grounded Conductor ("Neutral") FLA: 18.0 Amps.
(Largest Phase Load = 18.0 Amps)

TBCC: (3)
Total CCC: (3)
Maximum Number of 1PH. 3W. Multiwire Branch Circuits In A Single Raceway: (3)*
*:Figures = 9 TBCC (9 CCC) using #12 THHN Cu., 20 Amp OCPD.
#12 THHN Cu. @ 90C = 30 Amps.
7-9 CCC = 0.7 Derating Factor
30.0 Amps * 0.7 = 21.0 Amps
----------------------------------------------------------------------------------------------

Circuits 6/8; 2x 120V 1 Phase 2 Wire Branch Circuits (L-N).

Circuit #6 FLA: 12.0 Amps (L1 & L0).
Loads:
a.: 2.0 Amp Resistive (Linear, 1.0 PF)
b.: 4.0 Amp Reactive - Inductive (Non-Linear, 0.8 PF)
c.: 6.0 Amp Reactive - Impedance (Linear, 0.98 PF)

Circuit #8 FLA: 18.0 Amps (L2 & L0).
Loads:
a.: 3.0 Amp Resistive (Linear, 1.0 PF)
b.: 6.0 Amp Reactive - Inductive (Non-Linear, 0.8 PF)
c.: 9.0 Amp Reactive - Impedance (Linear, 0.98 PF)

No Common Grounded Conductor ("Neutral")

TBCC: Per Circuit: (2), For CKT 6/8: (4)
Total CCC: Per Circuit: (2), For CKT 6/8: (4)
Maximum Number of 1PH. 2W. Branch Circuits In A Single Raceway: (4)*
*:Figures = 8 TBCC (8 CCC) using #12 THHN Cu., 20 Amp OCPD.
#12 THHN Cu. @ 90C = 30 Amps.
7-9 CCC = 0.7 Derating Factor
30.0 Amps * 0.7 = 21.0 Amps
----------------------------------------------------------------------------------------------


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==============================================================================================





*** PART 1 OF 2: THREE PHASE FOUR WIRE - WYE ***
Source: 208Y/120V 3Ph. 4W Transformer (PHASE A, B & C)

This Part of the drawing Depicts The Four-Wire Star (Wye) Configuration Of The Transformer's
Secondary Windings, The Phase Voltage (120V), The Line Voltage (208V),
Phase A, B & C Termination To The Panelboard's Main Breaker / Bus Kit,
And Where The System's Grounded Conductor Is derived (at the "Star Point").

FYI: Transformer's "X" Terminals Are As Follows:

1.: "X1" = Phase "A"
2.: "X2" = Phase "B"
3.: "X3" = Phase "C"
4.: "X0" = "Star Point" (This Is The System's Grounded Conductor / Neutral)

----- THIS DRAWING CONNECTS TO THE BUS KIT (PART 2 OF 2) VIA THE LOWER-MOST TERMINATIONS -----

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*** PART 2 OF 2: THREE PHASE FOUR WIRE - WYE ***
Source: 208Y/120V 3Ph. 4W Transformer (PHASE A, B & C)



----------Left-Side Circuits:----------

Circuits 1/3/5; 208y/120v 3 Phase 4 Wire Multiwire Circuit (L-L-L-N).

Circuit #1 FLA: 6.0 Amps.
Loads:
a.: 6.0 Amp Resistive (Linear, 1.0 PF)
(2.0A + 2.0A + 2.0A)

Circuit #3 FLA: 9.0 Amps.
Loads:
a.: 9.0 Amp Resistive (Linear, 1.0 PF)
(3.0A + 3.0A + 3.0A)

Circuit #5 FLA: 12.0 Amps.
Loads:
a.: 12.0 Amp Resistive (Linear, 1.0 PF)
(4.0A + 4.0A + 4.0A)


Common Grounded Conductor ("Neutral") FLA: 5.196 Amps.

TBCC: (4)
Total CCC: (3)
Maximum Number of 3PH. 4W. Multiwire Branch Circuits In A Single Raceway: (3)*
*:Figures = 12 TBCC (9 CCC) using #12 THHN Cu., 20 Amp OCPD.
#12 THHN Cu. @ 90C = 30 Amps.
7-9 CCC = 0.7 Derating Factor
30.0 Amps * 0.7 = 21.0 Amps
----------------------------------------------------------------------------------------------

Circuits 7/9/11; 208y/120v 3 Phase 4 Wire Multiwire Circuit (L-L-L-N).

Circuit #7 FLA: 6.0 Amps.
Loads:
a.: 4.0 Amp Resistive (Linear, 1.0 PF)
(2.0A + 2.0A)
b.: 2.0 Amp Reactive - Inductive (Non-Linear, 0.8 PF)

Circuit #9 FLA: 9.0 Amps.
Loads:
a.: 3.0 Amp Resistive (Linear, 1.0 PF)
b.: 6.0 Amp Reactive - Inductive (Non-Linear, 0.8 PF)
(3.0A + 3.0A)

Circuit #11 FLA: 12.0 Amps.
Loads:
a.: 8.0 Amp Resistive (Linear, 1.0 PF)
(4.0A + 4.0A)
b.: 4.0 Amp Reactive - Inductive (Non-Linear, 0.8 PF)

Common Grounded Conductor ("Neutral") FLA: 10.583 Amps.

TBCC: (4)
Total CCC: (4)
Maximum Number of 3PH. 4W. Multiwire Branch Circuits In A Single Raceway: (2)*
*:Figures = 8 TBCC (8 CCC) using #12 THHN Cu., 20 Amp OCPD.
#12 THHN Cu. @ 90C = 30 Amps.
7-9 CCC = 0.7 Derating Factor
30.0 Amps * 0.7 = 21.0 Amps
----------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------

----------Right-Side Circuits:----------

Circuits 2/4/6; 208y/120v 3 Phase 4 Wire Multiwire Circuit (L-L-L-N).

Circuit #2 FLA: 6.0 Amps.
Loads:
a.: 6.0 Amp Reactive - Inductive (Non-Linear, 0.8 PF)
(2.0A + 2.0A + 2.0A)

Circuit #4 FLA: 9.0 Amps.
Loads:
a.: 9.0 Amp Reactive - Inductive (Non-Linear, 0.8 PF)
(3.0A + 3.0A + 3.0A)

Circuit #6 FLA: 12.0 Amps.
Loads:
a.: 12.0 Amp Reactive - Inductive (Non-Linear, 0.8 PF)
(4.0A + 4.0A + 4.0A)

Common Grounded Conductor ("Neutral") FLA: 12.0 Amps.

TBCC: (4)
Total CCC: (4)
Maximum Number of 3PH. 4W. Multiwire Branch Circuits In A Single Raceway: (2)*
*:Figures = 8 TBCC (8 CCC) using #12 THHN Cu., 20 Amp OCPD.
#12 THHN Cu. @ 90C = 30 Amps.
7-9 CCC = 0.7 Derating Factor
30.0 Amps * 0.7 = 21.0 Amps
----------------------------------------------------------------------------------------------

Circuits 8/10/12; 3x 120v 1 Phase 2 Wire Branch Circuits (L-N).

Circuit #8 FLA: 9.0 Amps (PH. A & L0).
Loads:
a.: 9.0 Amp Reactive - Inductive (Non-Linear, 0.8 PF)
(2.0A + 3.0A + 4.0A)

Circuit #10 FLA: 12.0 Amps (PH. B & L0).
Loads:
a.: 12.0 Amp Reactive - Inductive (Non-Linear, 0.8 PF)
(3.0A + 4.0A + 5.0A)

Circuit #12 FLA: 15.0 Amps (PH. C & L0).
Loads:
a.: 15.0 Amp Reactive - Inductive (Non-Linear, 0.8 PF)
(4.0A + 5.0A + 6.0A)

No Common Grounded Conductor ("Neutral").

TBCC: Per Circuit: (2), For CKT 8/10/12: (6)
Total CCC: Per Circuit: (2), For CKT 8/10/12: (6)
Maximum Number of 1PH. 2W. Branch Circuits In A Single Raceway: (4)*
*:Figures = 8 TBCC (8 CCC) using #12 THHN Cu., 20 Amp OCPD.
#12 THHN Cu. @ 90C = 30 Amps.
7-9 CCC = 0.7 Derating Factor
30.0 Amps * 0.7 = 21.0 Amps

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< END >


Edited by Scott35 (02/08/15 11:56 PM)
Edit Reason: Insert Medium Size Images
_________________________
Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!