You've hit a common problem with cage clamp terminals and stranded conductors, especially larger sizes. Here's a breakdown of possible solutions and advice

1. The Obvious (But Critical): Verify Conductor Size and Terminal Rating
Double-Check AWG Size

Make absolutely sure the AWG of your conductor falls within the acceptable range specified in the LRD3365 manual for the cage clamp terminals. Too small a conductor is a very common cause of this issue. The manual will specify both AWG range and solid/stranded conductor compatibility.

Solid vs. Stranded

Some cage clamps are optimized for solid conductors. If your LRD3365 specifically calls for solid conductors, you must use solid or properly prepared stranded conductors.

2. Conductor Preparation - Key to Success Cleanliness

Ensure the conductor strands are clean and free of corrosion or contaminants. A wire brush can help.

Re-strip

If the exposed conductor length is too long, strands can bend backward when inserted, preventing a good connection. If it's too short, the clamp might grip the insulation instead of the conductor. Use a proper wire stripper to ensure the correct length.

Twist the Strands Tight BEFORE Insertion

This is critical. Before inserting the conductor into the cage clamp, tightly twist the exposed strands together using pliers. This creates a more compact and solid "pseudo-solid" conductor that the cage clamp can grip effectively. You're aiming to make the stranded conductor act more like a solid conductor.

Don't Over-Twist

Twist until the strands are tightly packed, but not so much that you damage the insulation or distort the conductor.

3. Ferrules (The Recommended Solution - If Allowed by LRD3365) Ferrules are Ideal

Using ferrules designed for stranded wire and the correct crimping tool is the BEST solution for cage clamp terminals. A ferrule compresses the strands into a solid, gas-tight connection.

Compatibility

Crucially, check the LRD3365 manual! Some cage clamp terminals are specifically designed to accept ferrules; others are not. Using the wrong ferrule can actually worsen the connection or damage the terminal. The manual should specify the type and size of ferrule if permitted.

Correct Crimping Tool

You MUST use a proper ferrule crimping tool. Using pliers or other improvised methods will result in a poor connection and potential failure.

Insulated vs. Uninsulated Ferrules

Use the type specified by the manufacturer (usually insulated for safety).

Proper Ferrule Size

Match the ferrule size to the conductor size according to the ferrule manufacturer's recommendations. Too large a ferrule won't compress the strands properly; too small a ferrule won't fit the conductor.

4. Torque and Tightening Technique Calibrated Torque Screwdriver

Use a calibrated torque screwdriver to achieve the exact torque specified by Schneider (9 Nm / 79 lb-in). "Feeling" the torque is not accurate enough. Over-tightening can damage the terminal or the screw.

Gradual Tightening

Tighten the screw in stages. Tighten it a little, then wait a few seconds, then tighten it a little more until you reach the specified torque. This allows the conductor to settle within the clamp.

Re-Torque After a Short Period

After the initial installation, re-torque the screws after a few hours or a day. Conductors can compress slightly over time, requiring a slight re-tightening.

Inspect for Damage

Carefully inspect the terminal screws for any signs of damage (stripped threads, bent heads) after the electrician has been tightening them "nearly to failure." Damaged screws will not hold torque correctly.

5. Alternative Connection Methods (If Acceptable - Generally NOT Applicable to OLRs) Lugs and Terminal Blocks (Generally Not for OLRs)

If the application allows (and this is usually NOT the case for overload relays, but check), consider using lugs crimped onto the conductors and connecting them to a separate terminal block with screw terminals. This is a more robust solution for larger conductors. This is likely NOT possible as it would require changing the overload relay itself, and this is rarely an option.

6. Troubleshooting Steps Power Down

Always de-energize the circuit before working on electrical connections.

Inspect Terminals

Carefully examine the cage clamp terminals for any signs of damage (corrosion, cracks, deformation). Replace any damaged terminals.

Test for Tightness

After tightening, gently tug on each conductor to ensure it's securely held.

Thermal Imaging (If Available)

If you have access to a thermal imaging camera, you can use it to scan the terminals after the system is energized. A loose connection will often generate excessive heat.

Important Safety Notes



Qualified Electrician

All electrical work should be performed by a qualified and licensed electrician who is familiar with the applicable electrical codes and safety regulations.

Lockout/Tagout

Always follow proper lockout/tagout procedures to ensure the circuit is de-energized before working on it.*

Personal Protective Equipment (PPE)

Wear appropriate PPE, such as safety glasses and insulated gloves.

In summary, the best solution is usually


Verify conductor size and type suitability with the LRD3365 manual.2. Tightly twist the conductor strands before insertion.3. Use the correct torque value (9 Nm / 79 lb-in) and a calibrated torque screwdriver.4. Check the manual for ferrule compatibility and use the correct ferrules with the correct crimping tool if allowed.

If the problem persists, and you are sure everything else is correct, there may be an issue with the LRD3365 overload relay itself (damaged terminals). Contact Schneider Electric technical support for assistance. Flag for review