Daviteq Latching Relay Output
LRO
New replacement products
Replaced SKU
Gallery
1. Introduction
Overview
LRO is a node with latching relay output to electrically operate switch that uses a small electrical signal to control a larger electrical circuit. It works by energizing a ON relay coil or OFF relay coil, which creates a magnetic field that moves an armature to open or close contacts, allowing or interrupting the flow of electricity. This makes relays essential for controlling high-power devices with low-power signals. The LRO can be integrated into the wireless transmitter from Daviteq, such as Sub-GHz WS433, LoRaWAN WSLRW, and Sigfox WSSFC, to build the complete wireless latching relay output.
Latching relays are commonly used in applications where it is necessary to maintain the last state after a power failure such as industrial machinery, automate home systems like lighting and heating, regulate pumps and valves in water treatment plants, optimize irrigation in agriculture, control energy distribution in buildings, and operate urban infrastructure such as streetlights and traffic signals.
Specifications
Number of relay channel:1 channel/2 channel/4 channel
Contact rating: Electro-mechanical relays, SPST (NO) 250 VAC@8A (resistive load) 24 VDC@5A (resistive load), 10,000,000 operations min. (at 18,000 operations/h)
Control functions: On/Off based on control schedule, power up, fallback
2. Principle of Operation
A latching relay works as below:
Activation: When a control signal (usually a pulse) is applied to the relay coil, it energizes the coil and changes the state of the relay contacts (from open to closed or vice versa). This state is maintained even after the control signal is removed.
Latched State: The relay remains in this state without requiring continuous power, making it energy efficient. It stays latched until another control signal is applied to change its state again.
Deactivation: To reset the relay, a second control signal is applied to a different coil which changes the state of the contacts back to their original position.
Latching relays are commonly used in applications where it is necessary to maintain the last state after a power failure.
3. Calibration
Calibrating a latching relay involves several steps to ensure it operates correctly and reliably. Here's a general guide:
Initial Inspection: Check the relay for any physical damage or wear. Ensure all connections are secure.
Setup: Connect the relay to a testing circuit. This typically includes a power supply, control signals, and measurement instruments like a multimeter or oscilloscope.
Apply Control Signals: Send the appropriate control pulses to the relay to switch its state. Verify that the relay latches and unlatches correctly with each pulse.
Measure Contact Resistance: Measure the resistance across the relay contacts in both latched and unlatched states. Ensure the resistance is within the specified range for your relay.
Check Coil Resistance: Measure the resistance of the relay coil to ensure it matches the manufacturer's specifications.
Functional Testing: Perform a series of functional tests to ensure the relay operates correctly under
different conditions. This may include varying the input voltage and checking the relay's response time.
Document Results: Record all measurements and observations. Compare them with the manufacturer's specifications to ensure the relay is calibrated correctly.
4. Application Notes
5. Installation Notes
Some important notes for installing a latching relay:
Read the Manual: Always start by reading the manufacturer's installation manual for specific instructions and safety guidelines.
Power Supply: Ensure the power supply voltage matches the relay's contact specifications. Incorrect voltage can damage the relay contact or cause it to malfunction.
Wiring: Follow the wiring diagram provided by the manufacturer. Properly connect the control signals, power supply, and load. Double-check all connections to avoid short circuits or incorrect operation.
Mounting: Securely mount the relay in a suitable location. Ensure it is protected from dust, moisture, and excessive vibration.
Testing: After installation, test the relay by applying control signals to ensure it latches and unlatches correctly. Verify that the relay maintains its state without continuous power.
Safety Precautions: Always turn off the power before making any connections or adjustments. Use appropriate personal protective equipment (PPE) to avoid electrical hazards.
Environment: Ensure the relay is installed in an environment within its operating temperature and humidity range. Extreme conditions can affect its performance.
Maintenance: Periodically check the relay for signs of wear or damage. Clean any dust or debris that may accumulate on the contacts or housing.
6. Troubleshooting
Common troubleshooting steps for latching relays:
Check Power Supply: Ensure the relay contact is receiving the correct voltage and current. An unstable or incorrect power supply can cause the relay to malfunction.
Inspect Connections: Verify that all wiring connections are secure and free from corrosion. Loose or corroded connections can prevent the relay from operating correctly.
Test Control Signals: Use a multimeter to check that the control signals are reaching the relay properly. Incorrect or weak signals can cause the relay to fail to latch or unlatch.
Examine Relay Contacts: Look for signs of wear, dirt, or oxidation on the relay contacts. Clean them with a suitable contact cleaner if necessary. Worn or dirty contacts can lead to poor performance.
Look for Mechanical Obstructions: Ensure there are no mechanical obstructions preventing the relay from switching. Sometimes, debris or misalignment can cause the relay to stick.
Test in Isolation: If possible, test the relay in isolation from the rest of the circuit. This can help identify whether the issue is with the relay itself or another component in the circuit.
Replace Faulty Components: If any components are found to be faulty, replace them with new ones that meet the manufacturer's specifications.
Regular maintenance and periodic testing can help prevent issues with latching relays and ensure they operate reliably. If you encounter persistent problems, consulting the manufacturer's documentation or seeking professional assistance may be necessary.
7. Maintenance
Maintaining a latching relay is crucial for ensuring its longevity and reliable performance. Here are some key maintenance steps:
Regular Inspection: Periodically inspect the relay for any signs of wear, damage, or overheating. Check the housing and connections to ensure everything is intact.
Clean Contacts: Clean the relay contacts to remove any dirt, dust, or oxidation that may accumulate over time. Use a suitable contact cleaner and a soft brush to gently clean the contacts.
Check Connections: Ensure all wiring connections are secure and free from corrosion. Loose or corroded connections can lead to poor performance or failure.
Test Operation: Regularly test the relay's operation by applying control signals and verifying that it latches and unlatches correctly. This helps ensure the relay is functioning as expected.
Monitor Environment: Ensure the relay is operating within its specified temperature and humidity range. Extreme conditions can affect its performance and lifespan.
Replace Worn Components: If any components show signs of wear or damage, replace them with new ones that meet the manufacturer's specifications.
By following these maintenance steps, you can help ensure your latching relay operates reliably and efficiently.
8. Default Configuration
This LRO has the default configuration, however, those parameters can be changed. The user can change the configuration on the wireless transmitter so that the complete node(converter+ wireless) delivers the proper output value. Please check the Payload document for more information.