For use with equipment that cycles on and off, these relays meet UL 508 for air conditioning and heating. Connections are accessible from the front, so you can mount relays side-by-side. Also known as definite-purpose contactors.

Enclosures (sold separately) are NEMA 1 rated to protect contacts from corrosion.

Also Available: Auxiliary contacts for 3.8"-7.2" Ht. relays. They allow you to add a signaling device or control another relay. Please select 6564K99, then select the McMaster-Carr part number of your relay and whether you want to switch one circuit on (1 Normally Open) or off (1 Normally Closed).

For technical drawings and 3-D models, click on a part number.

Operate equipment that cycles on and off from your control cabinet. Often called definite-purpose contactors, these relays meet UL 508 for use with air conditioning and heating. They mount directly to 35 mm DIN rail (also known as DIN 3 rail) for fast installation. These relays have recessed terminals that prevent fingers and other objects from touching live circuits.

Auxiliary contacts (sold separately) allow you to add a signaling device or control another relay.

For technical drawings and 3-D models, click on a part number.

Also known as automotive relays, these relays can handle high starting (inrush) currents.

Relays for surface mounting have a tab for added security in high-vibration applications.

Often used to regulate the speed of AC fans or keep a heater at a set temperature, these relays connect directly to sensors to calculate and adjust output power. This allows you to use an analog input without converting it to a digital signal to control output power. They are solid state and have no moving parts, so they require less maintenance and last longer, are quieter, and switch faster than mechanical relays. IP20 rated, they have recessed terminals that prevent fingers and other objects from touching live circuits. An integrated heat sink disperses heat to increase the relay’s current rating. The LED indicator shows input voltage loss and internal relay faults, so you can easily check that your system is operating properly.

Mount them on 35 mm DIN rail (also known as DIN 3 rail) for fast installation. They also mount to flat surfaces.

All relays have phase-angle switching to accurately control all types of loads. This mode signals at non-zero voltage, which can produce electrical noise. Choose relays with full-cycle switching for resistive loads. This mode signals at zero voltage, so electrical interference is lower than phase-angle switching.

Single-phase relays can be set to switch every 1, 4, or 16 cycles. When used with infrared heaters, they have an option to switch at the half cycle and again at the full cycle. When switching at 16 cycles or at the half cycle, these relays have a soft-start option to increase the output slower in high-inrush current applications.

Three-phase relays switch every cycle.

Relays with a potentiometer input can connect to an external potentiometer for manual control.

For technical drawings and 3-D models, click on a part number.

Attach these relays to a flat surface using the mounting hole. They have no moving parts, so compared to mechanical switches, they require less maintenance, last longer, and are quieter.

Delayed start (delay-on-make) relays allow you to set how long it takes for the relay to turn on after input voltage is applied. For example, a drill starts pumping a lubricant immediately, but it does not start rotating until the set time has elapsed.

Delayed switch-off (delay-on-break) relays activate with a switch instead of input voltage. When the switch is turned off, the relay remains on for a programmed amount of time before turning off. For example, a projector’s light is turned off with a switch, but its cooling fan continues to run for a set time.

Interval relays use input voltage to turn on for a programmed amount of time. For example, when a part moving down a conveyor reaches a certain location, a cleaning spray comes on for a set time.

Repeat cycle relays turn on for a duration, then off for the same duration. They alternate between the two cycles until input voltage is removed. A common example would be a flashing light.

Switch-on (single-shot) relays require a switch to activate the relay. They’ll stay on for a programmed amount of time. For example, lights in a storage room are turned on with a switch and stay on for a set time before turning off.

For technical drawings and 3-D models, click on a part number.