After you have placed a symbol on a drawing, you can associate it with a plant item. You carry out this association by dragging a plant item from the Electrical Index to the symbol in the open drawing.
Associating Compound and Nested Symbols
When associating a compound symbol with a plant item that has child items, the software automatically associates the child plant items with the nested symbols that reside in the associated compound symbol. For example, a circuit in your plant can have several child items such as a circuit breaker, a fuse, and starter. If you associate a compound symbol with this circuit, the nested symbols residing in that compound symbol will automatically be associated with child items of that plant circuit. The software identifies the item type of each nested symbol and associates it with the appropriate plant child item. In case there are several child items that belong to the same item type, the software uses the sequence in group number to make the appropriate association.
Therefore, it is recommended that you create your compound symbols to fit the structure of your plant items. Here is another example:
A circuit in your plant that has two fuses, a starter, and a circuit breaker. We recommend that you use a circuit assembly symbol that looks like so:
As you can see, there are two nested fuse symbols, each one identified by a number shown on the ribbon. After you associate this circuit assembly compound symbol with your plant item, the software automatically associates the nested symbols with the child items of that circuit. The nested fuse symbol whose number is 1 (as shown above) will be associated with the plant fuse that has the lowest sequence in group number and the second nested fuse symbol will be associated with the second fuse belonging to that plant circuit.
For more information about how to make the actual association, see Associate a Symbol with a Plant Item.
Dissociating Compound and Nested Symbols
When dissociating a compound symbol from a plant item, the software also automatically dissociates all the nested symbols. Therefore, if you want to dissociate a nested symbol or change the association of a nested symbol, do not dissociate the compound symbol.
For more information, see Dissociate a Symbol from a Plant Item.
Changing the Association of Nested Symbols
As stated above, the software automatically associates nested symbols with the appropriate child items of the plant item associated with the compound symbol. It is not possible to associate nested symbols with plant items without first associating the compound symbol first. After the nested symbols have been associated, you can manually change the association of the nested symbols by using the Smart Selection tool to select the required nested symbol.
You must first dissociate the nested symbol from its plant item and only then make a new association. You can use the Smart Selection tool to select the required nested symbol.
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The software validates that the plant item that you selected for the association is a child item of the main plant item in the compound symbol. If the plant item that you selected for this association is a child item of another plant item that is not related to the current symbol, the software displays a message letting you decide whether to make this association or not.
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If there are more child plant items than nested symbols in the compound symbol, the software automatically associates those child plant items that have the highest sequence in group value. Those child plant with the lowest sequence in group values for which there aren't enough nested symbols will not be associated with any symbol.
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If there are more nested symbols than child plant items, these nested symbols will remain unassociated.
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If you change the sequence in group of a child plant item, you need to change the association manually.
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If you delete the main plant item, all the nested symbols as well as the parent symbol in that compound symbol become dissociated.
Deleting Plant Items from the Plant
When deleting a plant item in the Electrical Index, the software now automatically updates the associated compound symbol. The software behaves as follows:
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If the deleted plant item was associated with the parent compound symbol, the software dissociates the remaining plant items from the nested symbols and automatically refreshes the compound symbol in the drawing. In the example shown below, deleting the motor M-3A in the Electrical Index will cause the software to dissociate the heater H-M-3A and the CS-2 control station from the nested symbols. The compound symbol itself will remain intact. The software performs this update automatically on the fly.
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If the deleted plant item is associated with one of the nested symbols, the software dissociates the nested symbol from the deleted plant item and automatically refreshes the display of the compound symbol in the drawing.