G3.1 Relays

Pin numbers for relays follow EN 50005.

The coil contacts shall be named A1 and A2.
- For more complex relay magnetics, each coil pin shall have a letter and a number. The letter shall describe which coil the pin belongs to; the digit shall describe the tap number in that coil.
- Bistable relays shall have current flowing at the A1 pin in the A coil Set the relay and be labelled S+ or S-.
- Bistable relays should be labeled R+ or R- in the Reset coil or direction as well.
- In Bistable relays, labeling the positive direction that the current flows from shall be preferred over labeling the negative direction that the current flows to. Where it is not possible to label the positive direction, such as center-tapped relays with current always flowing from the center tap, the negative direction should be labelled.
Contacts shall have two digits each. The first digit shall be the index number of the pole group; the second digit shall describe the function.
- Normal-Close (NC) contacts shall be x1 and x2
- Normal-Open (NO) contacts shall be x3 and x4
- Changeover contacts shall be x1 for the common contact, x2 for NC, and x4 for NO

NC Contacts Example

NO Contacts Example

Changeover Contacts Example

Multiple Poles Example

Bistable Relay Example

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