This Omron G7Z-3A1B-11Z DC24 power relay has an auxiliary contact block, screw terminals for connecting contacts and is suitable for use in high power applications. This relay has a main circuit of triple pole single throw normally open (3PST-NO) contacts and single pole single throw normally closed (SPST-NC) contacts; and an auxiliary contact block of single pole single throw normally open (SPST-NO) and single pole single throw normally closed (SPST-NC) contacts. It has an input current rating of 154 mA and a load rating of 440VAC at 40 amp NO and 440VAC at 25 amp NC, with input of 24VDC. This relay has bifurcated contacts which is one contact split into two for a more stable mechanical operation, improved electrical contact, and heat dissipation. This power relay has screw terminals for connecting to contacts, mounts to an equipment rack (DIN track), and is suitable for use in switching power to motors and industrial equipment.SpecificationsContact FormMain: 3PST-NO/SPST-NC Auxiliary: SPST-NO/SPST-NCInput Current Rating154 mAInput Voltage24VDCLoad RatingNO: 440VAC, 40 ampNC: 440VAC, 25 ampDielectric Strength4,000VACOperating Temperature-25 to +60 degrees CEnclosure Dimensions*84 x 45 x 62mm (H x W x D)Standards MetUL (Underwriter's Laboratories)CSA (Canadian Standards Association)RoHS (Restriction on Hazardous Substances)*H is height, the vertical distance from the lowest to highest point; W is width, the horizontal distance from left to right; D is depth, the horizontal distance from front to back.Relay switches (also called an electrical relay or an electrical relay switch) use a small amount of power to control a larger source of power connected to electrical devices such as car motors, computers, and lighting installations. A basic relay switch has a control circuit with an electromagnetic coil and a load circuit with contacts and a lever. When current flows into the relay switch, it moves through the coil and a magnetic field is created, which causes the lever in the load circuit to move between contacts, either turning the device on or off. In a normally open (NO) relay switch, when power is supplied to the relay, the load circuit is closed and the power source connected to the relay is turned on. In a normally closed (NC) relay switch, when power is supplied to the relay, the load circuit is open and the power source connected to the relay is turned off. In other types of relay switches, non-moving parts such as transistors or semiconductors can be used as the control circuit to operate the switching mechanism. Relay switches can be controlled with an external switch, such as a light switch, or they can be connected to an automatically switched power source, such as a car ignition. One relay can operate multiple switches, and multiple relays can be operated with a single switch, with each relay operating independently from the other relays in the system.Omron manufactures and distributes electronic components, equipment, and systems for industrial automation. The company, founded in 1933, is headquartered in Kyoto, Japan.