Relay Specifications- Release Time

What is the Release Time of a Relay?

The Release Time of a relay is the transition time from the moment the voltage supply is stopped to the relay coil to the moment the normally open switch contact(s) open from its closed position.

When you supply a relay with its rated (or nominal) voltage, the normally open contacts up a relay close. However, when you remove the voltage from the relay coil, the normally open contacts that are closed snap back open (now that there is no power). The release time is the amount of time that it takes for the relay contact(s) to go from its closed position to its open position.

The Release Time of a relay includes the time for the magnetic field to weaken and cease (so the switch is no longer attracted, and, thus, closed), and the transfer time of the moveable contact (from its closed to its open position).

The Release Time for relays usually are in the milliseconds range; for example, a Panasonic JJM Series automotive relay has an release time of 10ms, when the voltage is cut off to the relay coil. The release time is usually comparable and, in fact, the same as the relay's operate time. This means that the time it takes for a relay's switch to close is usually the same as the time that it takes for a relay's switch to open.

Related Resources

Electrical Characteristics of Relays

Rated Coil Voltage of a Relay

Set (Operate) Voltage of a Relay

Rated Power of a Relay

Relay Specifications- Operate Time