LRD Thermal Overload Relay

Protect your motors from costly damage with the CDADA LRD Thermal Overload Relay, we are a professional supplier that can offer products for reliable, intelligent motor protection in industrial and commercial applications. Designed to work seamlessly with CDADA D-series contactors (D09–D95), the LRD relay provides comprehensive defense against:

● Overloads

● Phase failure (loss of phase)

● Excessively long starting times

● Prolonged rotor stalling

With an adjustable current range from 0.1A to 104A, manual or automatic reset options, and a built-in test button for circuit verification and trip simulation, the LRD series ensures both safety and ease of maintenance. The trip indicator offers clear visual status, while the sealed cover prevents unauthorized setting changes—ideal for harsh or regulated environments. Certified for global use and compatible with standard DIN-rail mounted contactors, CDADA’s LRD thermal relay is the smart choice for complete motor starter assemblies.

Key Specifications

Series: LRD Thermal Overload Relay

Brand: CDADA | Manufacturer: Shanghai DADA Electric CO.,LTD

Compatibility: Pairs with D09–D95 contactors (LC1-D series)

Rated Current Range: 0.1A – 104A (multiple models available)

Poles: 3-pole (monitors all phases for imbalance)

Protection Functions:

★ Thermal overload

★ Phase failure detection

★ Long start time monitoring

★ Rotor stall protection

Reset Mode: Manual or Automatic (selector switch)

Test Button: Simulates trip—activates both NO and NC auxiliary contacts

Stop Button: Opens NC contact only (for emergency stop signaling)

Trip Indicator: Visual flag shows tripped state

Setting Lock: Cover can be sealed to prevent tampering

Auxiliary Contacts: Standard 1NO + 1NC (for alarm, PLC, or interlock circuits)

Mounting: Directly mounts onto compatible CDADA contactors (snap-on design)

Certification: Compliant with IEC 60947-4-1 (CE documentation available)

Why Choose CDADA LRD Thermal Overload Relay?

★  Complete Motor Protection

Goes beyond basic overload—detects phase loss, long starts, and stalls that can silently destroy motors.

★ Seamless Contactor Integration

Snap-on design fits CDADA D09–D95 contactors perfectly—no brackets or adapters needed.

★ Maintenance-Friendly Features

★ TEST button verifies control circuit without power cycling

★ Clear trip indicator speeds up troubleshooting

★ Sealable cover meets safety audit requirements

★  Flexible Operation

Choose manual reset (for safety-critical systems) or auto reset (for unattended equipment).

★ Global Compatibility

Wide current range covers small pumps to large industrial motors—ideal for OEMs exporting worldwide.

★ Cost-Effective Safety

Prevents motor burnout, reduces downtime, and avoids expensive repairs—ROI in weeks.

★ We actively solicit feedback from clients and the market, conduct regular internal audits, invest in staff training and new technology, and benchmark against industry best practices.

★ Our pricing is competitive. We position ourselves not as the cheapest, but as offering the best value—superior quality, full certification, and strong service support compared to many smaller manufacturers.

Typical Applications

Motor Starter Assemblies: Paired with contactors for pumps, fans, compressors

Conveyor Systems: Protects against jam-induced stalls

HVAC Units: Guards chillers and blowers from phase imbalances

Agricultural Machinery: Irrigation pumps in rural areas with unstable grids

OEM Control Panels: Compact, reliable, and easy to wire

Frequently Asked Questions (FAQ)

Q1: What’s the difference between a thermal overload relay and an MPCB?

A1:

● MPCB (e.g., GV2/GV3): Combines short-circuit + overload + isolation in one device.

● Thermal Relay (LRD): Only provides overload & phase-loss protection—must be used with a contactor and fuse/MCB for full protection.

→ LRD is more precise for motor-specific faults and often lower cost in large installations.

Q2: Can I use LRD with non-CDADA contactors?

A2: The LRD is optimized for CDADA D-series (D09–D95). While mechanical fit may vary, we recommend using CDADA contactor-relay pairs for guaranteed performance and warranty support.

Q3: How does phase failure protection work?

A3: If one phase is lost, the remaining two phases draw higher current, causing uneven heating in the bimetallic strips. The LRD detects this imbalance and trips within seconds—preventing single-phasing damage.

Q4: What’s the purpose of the “Stop” button vs. “Reset” button?

A4:

● Stop Button: Temporarily opens the NC contact (e.g., for emergency signaling)—does not reset the relay.

● Reset Button: Returns the relay to ready state after a trip (only works when fault is cleared).

Q5: Why choose CDADA LRD over other brands?

A5: CDADA offers:

● True thermal differential mechanism (not electronic imitation)

● Full compatibility with D-series contactors—plug-and-play

● Sealable settings for compliance (e.g., ISO, safety audits)

● Test & stop buttons for enhanced diagnostics

● Competitive pricing with CE-compliant quality