Best Voltage Monitoring Relays in 2026

PRODUCT NAME---Voltage Monitoring Relay; Protection function: over voltage, under voltage; Rated voltage: DC 12V/24V/36V/48V; Overvoltage regulation range: 13-17v; Undervoltage adjustment range: 10-14v; Contact capacity: 6A 250VAC (resistivity)

REAL-TIME MONITORING---The voltage monitoring relay could achieve real-time monitoring of dc overvoltage and undervoltage faults, and over-voltage, under-voltage value, and action time can be adjusted

MAIN FEATURES---The voltage monitoring relay is of 2 sets of normally open and normally closed contacts, 2 indicator lights indicate various working conditions, no additional auxiliary power supply is required

Self-powered, no external power supply required.Action current 0.2-30A AC, adjustable with a potentiometer.

LED indicator can conveniently and intuitively indicate the working status of the switch.Hysteresis is less than 1% and can be used under strong magnetic conditions.

The switch has no limit on the number of opening and closing, and the speed reaches the ms level.The outer casing is made of self-extinguishing material ABS.

SELF-POWERED: Self-powered, no external power supply required.

CONTACTLESS ELECTRONIC SWITCH: High-power MOS tube contactless electronic switch.

STRUCTURE DESIGN: Straight-through structure design, isolation withstand voltage up to 2000V.

The Composition of This Product: Three-phase voltage protector, chronograph and counter are integrated in one relay.

Function: This voltage protection relay has overvoltage, undervoltage, phase loss, phase sequence and unbalanced three-phase voltage protection.

Practicality: This 3-phase voltage relay does not require an external power supply. Has practical functions: power delay, output test, etc

Product Type:Electronic Component

Item Package Dimension:10.921 Centimeters L X 9.906 Centimeters W X 3.048 Centimeters H

Country Of Origin: United States

2 INDICATOR LIGHT: Action time of over-voltage protection relay can be adjusted, 2 sets of normally open and normally closed contacts, 2 indicator lights indicate various working conditions

ADJUSTABLE: The overvoltage protector is not additional auxiliary power supply is required. Both over-voltage and under-voltage value can be adjusted

REAL-TIME MONITOR: The overvoltage undervoltage protector relay is convenient to use, real-time monitoring of dc overvoltage and undervoltage faults

Standard modular structure, guide rail type installation.

Ac/dc voltage universal, automatic identification of ac/dc voltage, no need to switch.

Built-in LCD Chinese display voltage value, fault status, setting parameters.

Product Type:Electronic Component

Item Package Dimension:10.414 Centimeters L X 9.144 Centimeters W X 3.048 Centimeters H

Country Of Origin: United States

When the measured voltage is within selected function and the set value, the output turn on to output voltage to control the normal operation of other equipment.

Adjustable reference voltage threshold.

Dual voltage signal comparison. 3 working mode.

Multi-Purpose: M3050 AC with rails current sensing switch is specially designed and manufactured to solve AC current monitoring. It uses the principle of mutual inductance to sense AC direct current, isolate the AC current, output normally open or normally closed switch signals, and directly control various automated industrial equipment, such as flash lamps, buzzers, relays, microcontrollers or other power load equipment.

Upgrade: Compared with traditional transformers, thermal protectors and other devices, using this device can not only get more accurate and timely control, but also greatly simplify the design and reduce costs. Self-powered, no external power supply required. Input through current: 0-30A AC Rated load: 0.3A@240V AC/DC.

High Performance: The switch has no limit on the number of times of opening and closing, and the response speed reaches the millisecond level. The hysteresis is less than 1% and can be used under strong magnetic conditions. Through structure design, isolation withstand voltage up to 2000V.

3-Phase Sequence/Loss Monitor

Monitors 208-480 VAC

5 Amp SPDT Relay Output

Channel difference is small, more accurate, 0.1V resolution accuracy. There are three versions of 5V / 12V / 24V optional.

Input a voltage compared with the reference voltage (reference voltage through precision multi-turn potentiometer partial pressure get),the input voltage is greater than the reference voltage, the relay pull, the circuit connected, at the same time the work of the corresponding channel indicator light.

Input a voltage compared with the reference voltage (reference voltage through precision multi-turn potentiometer partial pressure get), the input voltage is less than the reference voltage, the relay pulls, the circuit is connected, at the same time the work of the corresponding channel indicator light

1. 3V 1-Channel Relay interface board support photocoupler isolation control,has the output signal indicator,the signal input port can connect SCM IO port, high level signal drive

2. Support dual power supply input ensure high anti-interference ability,high reliability of photoelectric isolation protection

3. With diode continuous flow protection,response time is less than 20 milliseconds,long life of relay can be absorbed 100,000 times continuously

Product Type:Electronic Component

Item Package Dimension:10.921 Centimeters L X 10.16 Centimeters W X 3.048 Centimeters H

Country Of Origin: United States

Multi-Purpose: M3080 AC current sensing switch is specially designed and manufactured to solve AC current monitoring. It uses the principle of mutual inductance to sense AC direct current, isolate the AC current, output normally open or normally closed switch signals, and directly control various automated industrial equipment, such as flash lamps, buzzers, relays, microcontrollers or other power load equipment.

Upgrade: Compared with traditional transformers, thermal protectors and other devices, using this device can not only get more accurate and timely control, but also greatly simplify the design and reduce costs. Self-powered, no external power supply required. Input through current: 0-200A AC Rated load: 0.3A@240V AC/DC.

High Performance: The switch has no limit on the number of times of opening and closing, and the response speed reaches the millisecond level. The hysteresis is less than 1% and can be used under strong magnetic conditions. Through structure design, isolation withstand voltage up to 2000V.

【Adjustable AC Current】Action current 0.2-30A AC, adjustable with a potentiometer. Straight-through structure design, isolation withstand voltage up to 2000V. Self-powered, no external power supply required.

【Widely Used】Suitable for AC current measurement and monitoring, AC motor overload protection, electronic switch of automatic control system and so on. Compared with traditional mutual inductors, thermal protectors and other devices, using this device can not only get more accurate and more timely control, but can also greatly simplify the design and reduce costs.

【Quickly Responsive】High-power MOS tube contactless electronic switch. The switch has no limit on the number of opening and closing, and the speed reaches the ms level. LED indicator can conveniently and intuitively indicate the working status of the switch.

Voltage RegulationWhen a faulty line occurs, the voltage protection relay can adjust the overvoltage value and the action time, and record the fault for more flexible use.

Real-time MonitoringThe voltage protection relay can monitor overvoltage and undervoltage faults in real time and take protective measures in time.

LED DisplayThe voltage protection relay includes two sets of normally open and closed contacts, and the two indicator lights respectively indicate different working states.

【Quick Response】High-power MOS tube non-contact electronic switch, the current sensing switch has no limit on the number of times of opening and closing, and the response speed reaches the millisecond level.

【Widely Applicable】The shell is made of self-extinguishing material ABS, IP30 waterproof level, suitable for AC current measurement and monitoring, AC motor overload protection, automatic control system electronic switch.

【Stable Performance】The current sensing relay adopts a straight-through structure design. The isolation withstand voltage is up to 2000V, the hysteresis is less than 1%, and it can be used under strong magnetic conditions.

<b>Price For:</b> Each<b>Order Unit:</b> Each 1 <b>Contact Configuration:</b>: SPDT <b>Contact Current:</b>: 10 <b>Contact Voltage VAC:</b>: 250 <b>Contact Voltage VDC:</b>: - <b>Control Voltage Type:</b>: AC <b>Power Consumption:</b>: 11 <b>Product Range:</b>: SR Series <b>Relay Mounting:</b>: DIN Rail, Panel <b>Relay Terminals:</b>: Quick Connect <b>SVHC:</b>: To Be Advised <b>Supply Voltage Max:</b>: 220

Package Dimensions: 2.794 H x 10.414 L x 8.89 W (centimeters)

Package Weight: 0.25 pounds

Country of Origin : United States

Price For: Each Contact Configuration: SPDT Power Consumption: 1.2VA Supply Voltage Max: 120VAC Relay Mounting: DIN Rail Control Voltage Type: AC Series: 831 Accuracy: 1 % Carry Current: 15A No. of Poles: 1

22.5 mm wide

Can be digitally set and with LCD display

Fault memory that can be switched-in

3 PHASE

600 VAC

PHASE MONITORING RELAY

IMPORTANT PARAMETERS: ❶Protection function: over voltage, under voltage; ❷Rated voltage: DC 12V/24V/36V/48V; ❸Overvoltage regulation range: 13-17v; ❹Undervoltage adjustment range:10-14v; ❺Contact capacity: 6A 250VAC (resistivity).

REAL-TIME MONITORING: The voltage monitoring relay could achieve real-time monitoring of dc overvoltage and undervoltage faults, and over-voltage, under-voltage value, and action time can be adjusted.

MAIN ADVANTAGE: The voltage monitoring relay is of 2 sets of normally open and normally closed contacts, 2 indicator lights indicate various working conditions, no additional auxiliary power supply is required.

4 or 16 analog outputs

16-bit resolution

100 S/s update rate

Small Size: 2021 Improved Version, This 3-Phase Monitoring Relay has a smaller compact size for easier and convenient use and install, and the size of the Monitoring Relay is 8.1 x 6.7 x 1.75 cm/3.1 x 2.6 x 0.6 inch, you can install it on any places around the room, saving a lot of place

Multi-functioanl: This DPA51CM44 3-Phase Monitoring Relay has a widely use on the electric filed, and it can be applied to motor protection, elevator, air conditioning system, power system and other industries, very helpful tool during daily life

Work Well: DPA51CM44 3-Phase Monitoring Relay features with strong anti-interference performance, so it helps maintain a constant and efficient work of the motor, it will provide an excellent performance during the working process

For line and single-phase voltage monitoring

Can be used on all line supplies around the world (from 160V to 690V) without an auxiliary voltage

Can be digitally set, with fault memory and with LCD display

Control for protection of persons and equipment against the consequences of reverse running.

Protection against the risk of a driving load(Phase failure).

Normal/emergency power supply switching.

Anti Interference Performance--DPA51CM44 3-Phase monitoring relay features strong anti-interference performance

Monitoring Phase Sequence--3-phase monitoring relay for phase sequence and phase loss

Detects Correct Sequence--Detects when all phases are present and have the correct sequence