The relay industry has evolved with a set of its own nomenclature that describes the products available, however, not all of these terms are familiar to users. The following blog post seeks to describe and explain these relay terms.
Form A describes a relay whereby the contact is a simple switch, which is open or closed, and the un-energised position is the open condition. For a single relay this would also be described as a single pole, single throw (SPST) relay with a normally open (NO) contact.
If the relay has multiple contacts in the same package it would be described as having (for example) 2 Form A contacts (DPST).