The one-line diagram is different from a schematic or wiring diagram which shows exactly which wire is connected to what component terminal pin. The one-line diagram can show the incoming power and connected load strategy for overall system operation. This type of diagram shows the big picture.
A three-phase motor load uses three wires. Each wire has its own set of series-connected poles of a breaker or fuse, starter contact, overload, terminal, and pole in a safety switch. It is not necessary to repeat this information three times on the one-line diagram. A one-line diagram shows overall logic of what happens to all three of the wires, all the way from the incoming power connection until it reaches the motor load.
The one-line symbol library consists of all the one-line symbols and is found under
A one-line symbol can be a parent, child, or terminal. These one-line symbols use the same attributes as the schematic parent, child, and terminal symbols but with the following exceptions.
The attribute must be present and carry a value of "1-" to indicate it is a one-line symbol, or "1-1" for the one-line bus-tap symbols. A bus-tap symbol is used to mark the beginning of a one-line circuit. Schematic symbols do not carry this attribute or have the attribute but with a blank value.
Omitted from one-line cable markers symbols since a one-line cable marker can represent multiple conductors, multiple wires, or core color assignments.
Omitted from one-line terminal symbols since a one-line terminal can represent multiple independent terminals.
If a TERM01 attribute is added to a one-line symbol and carries a non-blank value, it can be edited in the Insert/Edit Terminal Symbol dialog box. However, terminal number text on one-line terminal symbols is not linked back to terminal number assignments on schematic or panel terminal representations.
Note: Terminal Strip Editor does not process one-line terminals.
One-line symbols follow the same naming convention as schematic parent and child symbols. For convenience, the one-line symbols provided have a "1-" suffix. However, the symbol name does not define the symbol as a one-line symbol. This is defined by the WDTYPE attribute value of "1-" on the symbol, or a "1-1" on a one-line symbol.
The bus-tap symbol can have two functions:
On a dual circuit one-line template, there are three bus-tap symbols. One at the normal point where the circuit ties into the bus. There is another version of the symbol on each of the two circuit "legs", each marking the point where that part of the dual circuit starts. These bus-tap symbols allow various reports to report accurately on a one-line circuit, whether a single circuit or a dual circuit representation.
The following bus-tap symbols are supplied:
Note: A WDTYPE attribute with a "1-1" value, identifies a bus-tap symbol.