Square D LRD07 TeSys Thermal Overload Relay 1.6–2.5A Motor Protection

The Square D LRD07 TeSys Deca Thermal Overload Relay is a compact and reliable motor protection relay designed to protect AC motors and motor starter circuits from overload and phase failure conditions. Part of the trusted Schneider Electric TeSys LRD family, this relay is engineered for use with TeSys D contactors to create dependable motor starter assemblies for industrial and HVAC applications.

The LRD07 features an adjustable overload setting range of 1.6 to 2.5 amps and is calibrated to Class 10A protection standards, helping minimize motor winding damage caused by excessive current or phase imbalance.

✅ Key Features

✔ Genuine Square D / Schneider Electric TeSys LRD relay
✔ Adjustable overload range: 1.6–2.5A
✔ Designed for use with TeSys D contactors (9A–38A range)
✔ Class 10A thermal overload protection
✔ Built-in 1NO + 1NC auxiliary contacts
✔ Red STOP / Blue RESET push-button operation
✔ Manual or automatic reset capability
✔ Phase failure sensitivity protection
✔ Temperature compensated performance
✔ Multi-standard certified (IEC, UL, CSA, CCC, EAC, ATEX, Marine)
✔ DIN rail, plate, or under-contactor mounting
✔ Compact design for industrial control panels
✔ EcoStruxure Facility Expert maintenance support

📊 Specifications

⚡ Electrical Protection Data

• Adjustable overload range: 1.6–2.5A
• Thermal overload class: Class 10A
• Tripping threshold: 1.14 ± 0.06 Ir (IEC 60947-4-1)
• Rated operational voltage: up to 690VAC
• Standard operating frequency: 50/60Hz
• Compatible frequency range: 0–400 Hz

Signalling Circuit Ratings

• 3A at 120V AC-15
• 0.22A at 125V DC-13
• Free air thermal current: 5A

Fuse Protection

• 4A gG signalling circuit fuse
• 4A BS signalling circuit fuse

🌡 Environmental & Protection Ratings

✔ Climatic withstand: IACS E10 certified
✔ Industrial and marine-grade durability

✔ IP degree of protection: IP20 (IEC 60529)
✔ Finger-safe protection for enclosed panels

✔ Operating temperature range:

• -20°C to +60°C (-4°F to +140°F)
• No derating required per IEC 60947-4-1

✔ Storage temperature range:

• -60°C to +70°C (-76°F to +158°F)

⚡ Electrical & Insulation Ratings

✔ Product type: Differential thermal overload relay
✔ Device short name: LRD
✔ Relay application: Motor protection

✔ Rated insulation voltage (Ui):

• 600V CSA
• 600V UL
• 690V IEC 60947-4-1

✔ Impulse withstand voltage (Uimp): 6 kV
✔ High resistance to electrical surge conditions

🔧 Mounting Options

✔ DIN rail mounting
✔ Plate mounting with accessories
✔ Under-contactor mounting with TeSys D contactors
✔ Flexible installation for motor starter panels

⚙ Protection Functions

✔ Motor overload protection
✔ Phase failure sensitivity
✔ Thermal trip protection (Class 10A)
✔ Automatic motor disconnection during overload conditions
✔ Adjustable trip calibration for precise motor protection

🔌 Connections & Terminal Specifications

✔ Control circuit screw clamp terminals:

• 2 conductors supported
• 0.002…0.004 in² (1…2.5 mm²) flexible without cable end
• 0.002…0.004 in² (1…2.5 mm²) flexible with cable end
• 0.002…0.004 in² (1…2.5 mm²) solid without cable end

✔ Power circuit screw clamp terminals:

• 1 conductor supported
• 0.002…0.02 in² (1.5…10 mm²) flexible without cable end
• 0.002…0.006 in² (1…4 mm²) flexible with cable end
• 0.002…0.009 in² (1…6 mm²) solid without cable end

🔩 Tightening Torque

✔ Control circuit terminals: 15.05 lbf.in (1.7 N·m)
✔ Power circuit terminals: 15.05 lbf.in (1.7 N·m)

🔌 Control & Auxiliary Functions

✔ Auxiliary contacts: 1NO + 1NC
✔ Red STOP push-button
✔ Blue RESET push-button
✔ Manual or automatic reset operation
✔ Signal feedback capability for control systems

📏 Physical Dimensions

✔ Height: 2.6 in (66 mm)
✔ Width: 1.8 in (45 mm)
✔ Depth: 2.8 in (70 mm)

✔ Compact footprint for industrial and HVAC panels

⚠ Common Symptoms of Faulty Overload Relay

• Motor fails to start
• Frequent overload trips
• Motor overheating
• Relay fails to reset
• Phase imbalance shutdowns
• Contactor dropping unexpectedly
• Intermittent motor operation

❓ Frequently Asked Questions (FAQ)

Q: What is the LRD07 used for?

It protects electric motors from overload, overheating, and phase failure conditions.

Q: What is the overload adjustment range?

The relay is adjustable from 1.6 to 2.5 amps.

Q: Does it work with TeSys D contactors?

Yes, it is designed for use with TeSys D contactors from 9A to 38A.

Q: Is the LRD07 compatible with both 50Hz and 60Hz systems?

Yes. The LRD07 is designed for standard 50/60Hz electrical systems and supports operating frequencies from 0–400 Hz.

Q: Does it support manual and automatic reset?

Yes, both reset modes are supported.

🛒 Shopping Tips

• Match overload range to motor FLA
• Verify compatibility with TeSys D contactor size
• Inspect terminals and wiring during replacement
• Use proper DIN rail or plate mounting hardware
• Confirm Class 10A protection requirements