Dry Contacts Electrical

A dry contact output on a device like a relay means that the contacts have no voltage or potential difference across the two contacts.

Dry contacts electrical. Usually some other contacts or devices have the job of starting or stopping the primary. The contacts simply provide an open or closed state to another device. A common example would be the contacts in a compressor contactor. Dry contacts are not directly provided with power from the switch and are used in switching devices which provide isolation and give a wide variety of output voltage options.

Or if the contact is mounted as part of an electrical unit that has a power source then the dry contact has no pre wired electrical connection to that power source. A dry contact is the synonym of volt free it is not wetted by a voltage source dry contact can refer to a secondary set of contacts of a relay circuit which does not make or break the primary current being controlled by the relay. Wet contacts are automatically given power when the switch has power and the main advantages are the simplicity of wiring and the consistency of voltage levels making. A dry contact is a contact that is not initially connected to a voltage source.

It could be stand alone such as a pressure switch mounted on a boiler. The contactor has a 24v coil in residential but the power supply through the contacts doesn t have any connection to the coil.