Parallel branch (OR) symbol
Also called OR logic, Branch, Contacts in parallel
Two paths side by side on a rung: power passes when either one is true, which is OR logic. A seal-in (holding) contact is a parallel branch.
IEC 61131-3What the parallel branch (OR) symbol means
Two paths side by side on a rung: power passes when either one is true, which is OR logic. A seal-in (holding) contact is a parallel branch.
How it is drawn
IEC 61131-3 ladder diagram
Parallel branch. Two contacts on branches that split and join again.
LD SVGWhere you see it
Alternative conditions, such as a local or a remote start, and the seal-in contact that keeps a motor running after the start button is released.
Related symbols
Frequently asked questions
What does the parallel branch (OR) symbol look like?
Two contacts on branches that split and join again.
Where is a parallel branch (OR) used?
Alternative conditions, such as a local or a remote start, and the seal-in contact that keeps a motor running after the start button is released.
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