The Amperite 24DF90D is a time delay relay. It is a single-phase, mechanically-held, adjustable time delay relay with a single-pole double-throw (SPDT) contact arrangement. This relay features a delayed NC (normally closed) contact, and a delayed NO (normally open) contact. It is current rated up to 5A at 250VAC or 28VDC. It can be set to delay periods of up to 30 minutes. This relay is typically used to delay the activation or deactivation of motors, lighting, or other machinery.