Simple Designated Circuit Drawings

I drew these Receptacle Circuits for an Electrical Contractor friend, to use as visual
Teaching aids for some of His Apprentices (or Journeypersons, if applicable).

Thought I would post them here too, for Members to use in discussions or for reference
purposes.

Let me know if you have suggestions, questions or comments.

Scott

*** PLEASE NOTE ***
The Panelboard used in these drawings has an Isolated Neutral Bus.
The System Bonding has been done at the Transformer, with an Equipment Grounding
Conductor brought to it with the Panelboard Feeders.

Panelboard image is crude, but has ample information to make sense.
==============================================================================================

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

*** Drawings Uploaded 05/24/2008 ***





FIGURE #1a: DEDICATED (DESIGNATED) CIRCUITRY - COMMON NEUTRAL:
ONE DUPLEX RECEPTACLE PER CIRCUIT

This Drawing shows a 208Y/120V 3 Phase 4 Wire Multiwire Circuit feeding
individual 20 Amp Receptacles - One Per Circuit.

Each Duplex Receptacle is fed with its own 20 Amp Circuit, which does not feed any other loads/outlets
("Dedicated Circuit" or 'Designated Circuit").

The 20 Amp Dedicated Circuit for each Receptacle is as follows:
* Ungrounded Conductor - Dedicated to one Receptacle,
* Grounded Conductor - "Shared" across all 3 Receptacles,
* Equipment Grounding Conductor - also "Shared" across all 3 Receptacles.

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




FIGURE #1b: DEDICATED (DESIGNATED) CIRCUITRY - COMMON NEUTRAL:
TWO DUPLEX RECEPTACLE PER CIRCUIT

This Drawing shows a 208Y/120V 3 Phase 4 Wire Multiwire Circuit feeding
individual 20 Amp Receptacles - Two Per Circuit.

Both Duplex Receptacle are fed with the same 20 Amp Circuit, which does not feed any other loads/outlets
("Dedicated Circuit" or 'Designated Circuit").

The 20 Amp Dedicated Circuit for each "Set" of Receptacles is as follows:
* Ungrounded Conductor - Dedicated to one "Set" of Receptacles,
* Grounded Conductor - "Shared" across all 6 Receptacles,
* Equipment Grounding Conductor - also "Shared" across all 6 Receptacles.

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



FIGURE #2a: DEDICATED (DESIGNATED) CIRCUITRY - DEDICATED NEUTRALS:
ONE DUPLEX RECEPTACLE PER CIRCUIT

This Drawing shows a 208Y/120V 3 Phase 4 Wire System feeding
individual 20 Amp Receptacles - One Per Circuit.

Each Duplex Receptacle is fed with a 20 Amp , 2 Wire Circuit, which does not feed any other loads/outlets ("Dedicated Circuit" or 'Designated Circuit").

The 20 Amp Dedicated Circuit for each Receptacle is as follows:
* Ungrounded Conductor - Dedicated to one Receptacle,
* Grounded Conductor - Dedicated to One Receptacle,
* Equipment Grounding Conductor - "Shared" across all 3 Receptacles.

*** FPN:
The Grounded Conductors used for the 20 Amp 2 Wire Branch Circuits are _NOT_ NEUTRALS!!!
They are simply the Grounded Conductor used for the "Second Part" of the 2 Wire Circuit.
The same load Current which flows on the Ungrounded "Hot" Conductor will flow on the Grounded Conductor.

This drawing is to demonstrate one of the Specifications an Electrical Engineer might insert on a Plan Set, or found in Division 16 of a Project Manual
(typically referred to as "Not Shared Neutrals", but may also be referred to as "1 Neutral Per Hot").

This Drawing also demonstrates the preferred Wiring method for some Electrical Contractors, to avoid the issues of an open Common Neutral, when dealing with Multiwire Systems.

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



FIGURE #2b: DEDICATED (DESIGNATED) CIRCUITRY - DEDICATED NEUTRALS:
TWO DUPLEX RECEPTACLE PER CIRCUIT

This Drawing shows a 208Y/120V 3 Phase 4 Wire System feeding
individual 20 Amp Receptacles - Two Per Circuit.

Both Duplex Receptacles are fed with the same 20 Amp , 2 Wire Circuit, which does not feed any other loads/outlets ("Dedicated Circuit" or 'Designated Circuit").

The 20 Amp Dedicated Circuit for each "Set" of Receptacles is as follows:
* Ungrounded Conductor - Dedicated to one "Set" of Receptacles,
* Grounded Conductor - Also Dedicated to one "Set" of Receptacles,
* Equipment Grounding Conductor - "Shared" across all 6 Receptacles.

*** FPN:
The Grounded Conductors used for the 20 Amp 2 Wire Branch Circuits are _NOT_ NEUTRALS!!!
They are simply the Grounded Conductor used for the "Second Part" of the 2 Wire Circuit.
The same load Current which flows on the Ungrounded "Hot" Conductor will flow on the Grounded Conductor.

This drawing is to demonstrate one of the Specifications an Electrical Engineer might insert on a Plan Set, or found in Division 16 of a Project Manual
(typically referred to as "Not Shared Neutrals", but may also be referred to as "1 Neutral Per Hot").

This Drawing also demonstrates the preferred Wiring method for some Electrical Contractors, to avoid the issues of an open Common Neutral, when dealing with Multiwire Systems.

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




FIGURE #3a: DEDICATED (DESIGNATED) CIRCUITRY - COMMON NEUTRAL, ISOLATED GROUND:
ONE DUPLEX RECEPTACLE PER CIRCUIT

This Drawing shows a 208Y/120V 3 Phase 4 Wire System feeding
individual 20 Amp Receptacles - One Per Circuit.
Isolated Equipment Grounding Conductor (Isolated Ground, or "IG")

Each Duplex Receptacle is fed with its own 20 Amp Dedicated Circuit, which does not feed any other loads/outlets
("Dedicated - Isolated Ground Circuit" or 'Designated - Isolated Ground Circuit").

The 20 Amp Dedicated Circuit for each Receptacle is as follows:
* Ungrounded Conductor - Dedicated to one Receptacle,
* Grounded Conductor - "Shared" across all 3 Receptacles,
* Isolated Grounding Conductor - Dedicated to One Receptacle,
* Equipment Grounding Conductor - "Shared" across all 3 Outlet Boxes (terminates to Outlet Box only).

*** FPN: For the IG Circuit Drawings, the "Isolated ground Bus" in the Panelboard is fed with a separate Equipment Grounding Conductor, ran with the Panelboard's Feeders - from the Transformer.

The IG Conductor is Insulated, and only terminates on the Isolated Ground Bus in the Panelboard, and the Grounding Conductors' termination point (lugs) at the Transformer - or at Transformer terminal "X0"

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




FIGURE #3b: DEDICATED (DESIGNATED) CIRCUITRY - COMMON NEUTRAL, ISOLATED GROUND:
TWO DUPLEX RECEPTACLE PER CIRCUIT

This Drawing shows a 208Y/120V 3 Phase 4 Wire System feeding
individual 20 Amp Receptacles - Two Per Circuit.
Isolated Equipment Grounding Conductor (Isolated Ground, or "IG")

Both Duplex Receptacle are fed with the same 20 Amp Dedicated Circuit, which does not feed any other loads/outlets
("Dedicated - Isolated Ground Circuit" or 'Designated - Isolated Ground Circuit").

The 20 Amp Dedicated Circuit for each "Set" of Receptacles is as follows:
* Ungrounded Conductor - Dedicated to one "Set" of Receptacles,
* Grounded Conductor - "Shared" across all 6 Receptacles,
* Isolated Grounding Conductor - Dedicated to One Receptacle _ONLY_ (total of Two IGCs per Circuit),
* Equipment Grounding Conductor - "Shared" across all 6 Outlet Boxes (terminates to Outlet Box only).

*** FPN: For the IG Circuit Drawings, the "Isolated ground Bus" in the Panelboard is fed with a separate Equipment Grounding Conductor, ran with the Panelboard's Feeders - from the Transformer.

The IG Conductor is Insulated, and only terminates on the Isolated Ground Bus in the Panelboard, and the Grounding Conductors' termination point (lugs) at the Transformer - or at Transformer terminal "X0"


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

< end >
_________________________
Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!