Electrical drawings

Block diagrams

These diagrams are simply made up of labelled blocks (boxes) joined by lines with arrowheads, much like a flowchart. They give a simple overview of how a system works, or how sections of a system relate to each other. This type of diagram is used to represent complete installations, allowing an electrician to quickly identify particular segments.

The diagrams don't contain any detail of circuit or component operation. They can help in diagnostics by indicating the relationship of each subsystem to the next.

In a very large installation a number of block diagrams may be used. There can be an overall (master) diagram, then particular blocks (subsystems) can be broken down into further block diagrams.

The following example shows a master diagram for a manufacturing plant . This is then followed by a second diagram, which is a block for one of the systems in the master diagram.

 

 

 

 

Block diagrams