Choosing an Electrical Switch
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DIN-Rail Mount Motor Voltage Monitors
Mount these monitors to 35 mm DIN rail. They protect electric motors from phase loss, phase reversal, overvoltage, undervoltage, and voltage imbalance. Also known as voltage-monitoring relays, they cut power to a motor when a fault occurs.
For technical drawings and 3-D models, click on a part number.
Switching | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Input Voltage Range  | No. of Terminals | Control Power, W | Voltage Imbalance Adjustment | Trip Time, sec. | Reset Type | Current, A | Voltage | Horsepower @ Voltage | Ht. | Wd. | Specifications Met | Each | |
1 Circuit Controlled with 1 Off (Normally Open) or 1 On (Normally Closed)—SPDT | |||||||||||||
Three Phase | |||||||||||||
| 200-480V AC | 9 | 5 | 2%-10% | 1-30 | Automatic | 10 | 240V AC | 1/3 hp @ 240 V AC | 3" | 2" | UL Listed, C-UL Listed | 0000000 | 0000000 |
Surface-Mount Motor Voltage Monitors
Protect electric motors from phase loss, phase reversal, overvoltage, undervoltage, and voltage imbalance. Also known as voltage-monitoring relays, these monitors cut power to a motor when a fault occurs.
For technical drawings and 3-D models, click on a part number.
Trip Time, sec. | Switching | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Input Voltage Range | No. of Terminals | Control Power, W | Voltage Imbalance Adjustment | Automatic Reset | Delayed Automatic Reset | Current, A | Voltage | Ht. | Wd. | Specifications Met | Each | |
1 Circuit Controlled with 1 Off (Normally Open) or 1 On (Normally Closed)—SPDT | ||||||||||||
Three Phase | ||||||||||||
| 190-480V AC | 7 | 6 | 2%-8% | 1-30 | 1-500 | 10 | 240V AC | 3.5" | 2.08" | UL Listed | 0000000 | 0000000 |
| 475-600V AC | 7 | 6 | 2%-8% | 1-30 | 1-500 | 10 | 240V AC | 3.5" | 2.08" | UL Listed | 0000000 | 000000 |
Socket-Mount Motor Voltage Monitors
Plug these monitors into relay sockets for fast installation and replacement. They protect electric motors from phase loss, phase reversal, overvoltage, undervoltage, and voltage imbalance. Also known as voltage-monitoring relays, they cut power to a motor when a fault occurs.
Relay sockets (sold separately) mount to 35 mm DIN rail or flat surfaces.
Voltage Monitors | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Switching | Relay Sockets | |||||||||||||
| Input Voltage Range | No. of Terminals | Control Power, W | Voltage Imbalance Adjustment | Trip Time, sec. | Reset Type | Current, A | Voltage | Ht. | Wd. | Specifications Met | Each | Each | ||
1 Circuit Controlled with 1 Off (Normally Open) or 1 On (Normally Closed)—SPDT | ||||||||||||||
Three Phase | ||||||||||||||
| 200-480V AC | 8 | 5 | 2%-10% | 0.25-30 | Automatic | 10 | 240V AC | 2.4" | 1.8" | UL Recognized Component, CSA Certified | 0000000 | 0000000 | 0000000 | 00000 |
Undervoltage Disconnect Switches
Prevent motors and other equipment from overheating or failing from not having enough voltage. When the supply voltage falls below 35% of the rated voltage, these switches will automatically turn off to protect the circuit from undervoltage. Once the power is cut, they'll keep it isolated to prevent accidental startups during inspection and maintenance.
To prevent unauthorized use of these switches, you can lock them out with a padlock (not included). Even if a padlock blocks them from physically turning off, they’ll disconnect power to the actuator if voltage falls below a safe level.
For technical drawings and 3-D models, click on a part number.
Switching | ||||||||
|---|---|---|---|---|---|---|---|---|
| Current, A | Voltage | Electrical Phase (hp) | Ht. | Wd. | Dp. Behind Panel | Environmental Rating | Each | |
Gray Plastic Housing with Black Actuator | ||||||||
Stays Switched (Maintained) | ||||||||
2 Circuits with Lockout—For 1/2" Panel Cutout Dia. | ||||||||
| 40 | 230V AC | Single (1 1/2 hp @ 120 V AC) Single (3 hp @ 240 V AC) Three (7 1/2 hp @ 240 V AC) | 2 5/8" | 2 5/8" | 3 1/8" | IP54 | 0000000 | 0000000 |
| 60 | 230V AC | Single (3 hp @ 120 V AC) Single (7 1/2 hp @ 240 V AC) Three (10 hp @ 240 V AC) | 2 5/8" | 2 5/8" | 3 1/2" | IP54 | 0000000 | 000000 |
3 Circuits with Lockout—For 1/2" Panel Cutout Dia. | ||||||||
| 40 | 400V AC | Single (1 1/2 hp @ 120 V AC) Single (3 hp @ 240 V AC) Three (7 1/2 hp @ 240 V AC) | 2 5/8" | 2 5/8" | 3 1/8" | IP54 | 0000000 | 000000 |
| 60 | 400V AC | Single (3 hp @ 120 V AC) Single (7 1/2 hp @ 240 V AC) Three (10 hp @ 240 V AC) | 2 5/8" | 2 5/8" | 3 1/2" | IP54 | 0000000 | 000000 |
Yellow Plastic Housing with Red Actuator | ||||||||
Stays Switched (Maintained) | ||||||||
2 Circuits with Lockout—For 1/2" Panel Cutout Dia. | ||||||||
| 40 | 230V AC | Single (1 1/2 hp @ 120 V AC) Single (3 hp @ 240 V AC) Three (7 1/2 hp @ 240 V AC) | 2 5/8" | 2 5/8" | 3 1/8" | IP54 | 0000000 | 000000 |
| 60 | 230V AC | Single (3 hp @ 120 V AC) Single (7 1/2 hp @ 240 V AC) Three (10 hp @ 240 V AC) | 2 5/8" | 2 5/8" | 3 1/2" | IP54 | 0000000 | 000000 |
3 Circuits with Lockout—For 1/2" Panel Cutout Dia. | ||||||||
| 40 | 400V AC | Single (1 1/2 hp @ 120 V AC) Single (3 hp @ 240 V AC) Three (7 1/2 hp @ 240 V AC) | 2 5/8" | 2 5/8" | 3 1/8" | IP54 | 0000000 | 000000 |
| 60 | 400V AC | Single (3 hp @ 120 V AC) Single (7 1/2 hp @ 240 V AC) Three (10 hp @ 240 V AC) | 2 5/8" | 2 5/8" | 3 1/2" | IP54 | 0000000 | 000000 |
Multifunction Monitoring Relays
Monitor phase, voltage, and frequency at the same time to protect motors, generators, and other three-phase circuits from burning out or overheating. They'll switch the circuit off if they detect voltage or frequencies outside of the set range or phase loss, imbalance, or reversal. Rated IP20, they have recessed terminals that keep fingers and other objects from touching live circuits. Mount them on a 35 mm DIN (also known as DIN 3 rail) for fast installation.
These relays use IO Link, so they can be programmed, monitored, and reset remotely by connecting them to a programmable logic controller (PLC), human-machine interface (HMI), or computer. If you want to program them locally, they have a keypad.
Relays with spring-clamp terminals connect and disconnect to wire without screws. Because there’s no screw, these connections are less likely to loosen over time, even in high-vibration environments.
For technical drawings and 3-D models, click on a part number.
Trip Voltage | Trip Frequency | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Number of Terminals | Input Voltage | Min. | Max. | Input Frequency, Hz | Min., Hz | Max., Hz | Trip Time, sec. | Reset Type | Switching Current @ Voltage | Max. Switching Voltage | Adjustment Style | Ht. | Wd. | Dp. | Each | |
1 Circuit Controlled with 1 Off (Normally Open) or 1 On (Normally Closed)—SPDT | ||||||||||||||||
With Screw Terminals and IO Link | ||||||||||||||||
| 12 | 24V DC | 90V AC | 760V AC | 50, 60 | 15 | 70 | 0.1-30 | Automatic | 3 A @ 240 V AC 1 A @ 24 V DC | 400V AC 250V DC | Keypad, External Controller | 3.9" | 0.9" | 3.6" | 0000000 | 0000000 |
With Spring-Clamp Terminals and IO Link | ||||||||||||||||
| 12 | 24V DC | 90V AC | 760V AC | 50, 60 | 15 | 70 | 0.1-30 | Automatic | 3 A @ 240 V AC 1 A @ 24 V DC | 400V AC 250V DC | Keypad, External Controller | 3.9" | 0.9" | 3.6" | 0000000 | 000000 |
Smart Multifunction Monitoring Relays
Remotely control these relays through an app on your smartphone—they simultaneously monitor phase, voltage, and frequency. The downloadable app lets you change the tripping range, modify settings, and save programs to apply to multiple relays. Tap your smartphone or tablet to the relays to connect to them. They use NFC (near field communication), so you don’t need to manually pair them like Bluetooth devices.
You’ll often see these relays used to protect motors, generators, and other three-phase circuits from burning out or overheating. They'll switch the circuit off if they detect voltage or frequencies outside of the set range or phase loss, imbalance, or reversal. You can see that they're wired correctly and when they're actuated based on the LED indicators. Rated IP20, they have recessed terminals that keep fingers and other objects from touching live circuits. Mount them on a 35 mm DIN rail (also known as DIN 3 rail) for fast installation.
For technical drawings and 3-D models, click on a part number.
Trip Voltage | Trip Frequency | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Number of Terminals | Input Voltage | Min. | Max. | Input Frequency, Hz | Min., Hz | Max., Hz | Trip Time, sec. | Reset Type | Switching Current @ Voltage | Max. Switching Voltage | Ht. | Wd. | Dp. | Operating System Compatibility | Each | |
2 Circuits Controlled with 2 Off (Normally Open) or 2 On (Normally Closed)—DPDT | ||||||||||||||||
With Screw Terminals | ||||||||||||||||
| 12 | 208V AC, 240V AC, 300V AC, 480V AC | 208V AC | 480V AC | 50, 60 | 45 | 66 | 0.1-60 | Automatic | 8 A @ 240 V AC | 250V AC | 3.5" | 0.9" | 3.9" | Android 7.0 or Later, iOS 14.5 or Later | 0000000 | 0000000 |