Samlex Solar MC4-2 Owner's Manual

The Samlex Solar MC4-2 is a high-quality, waterproof MC4 branch connector designed for connecting two solar panels in parallel to a single charge controller or inverter input. It features male and female MC4 connectors on one end and a single MC4 output on the other, built with UV-resistant housing and gold-plated contacts for optimal conductivity and durability in outdoor environments. Below are key sections for safety, features, installation, specifications, operation, and troubleshooting.

Features at a Glance

Key components: Waterproof MC4 housing, Gold-plated contacts, UV-resistant material, Integrated strain relief, Polarity markings.

Installation

Unpack and inspect contents. Ensure all components are present and undamaged.

1. Prepare cables: Strip approximately 1/4 inch (6mm) of insulation from the PV cable ends.
2. Insert cable: Insert the stripped conductor into the MC4 contact until it clicks securely.
3. Crimp connection: Use an MC4 crimping tool to secure the contact to the cable (if assembling new connectors).
4. Connect panels: Plug the male MC4 connectors from two solar panels into the female inputs of the MC4-2.
5. Connect to system: Plug the single male output of the MC4-2 into the female input of your charge controller or combiner box.

WARNING! Always disconnect the solar array from the charge controller and battery before making connections. Ensure all connections are dry and secure.

First-Time Setup

Integrate the MC4-2 into your solar array during initial system assembly.

1. Verify polarity: Confirm "+" and "-" alignment between panels and the MC4-2 connector.
2. Check voltage: Use a multimeter to verify open-circuit voltage of each panel before parallel connection.
3. Connect in parallel: Ensure both solar panels have similar voltage ratings before using the MC4-2 for parallel connection.
4. Test connection: After connection, check for secure fit and no exposed conductors.

CAUTION! Connecting panels with mismatched voltages in parallel can lead to reduced efficiency and potential damage. Always verify specifications.

Specifications

• Model: MC4-2 Parallel Branch Connector.
• Inputs: 2 x MC4 compatible (1 Male, 1 Female).
• Output: 1 x MC4 compatible.
• Rated Voltage: 1000V DC max.
• Rated Current: 30A per input, 30A total output.
• Contact Resistance: < 0.5mΩ.
• Insulation Resistance: > 100MΩ.
• Ingress Protection: IP67 (Dust tight and protected against immersion up to 1m).
• Wire Range: 10 AWG to 14 AWG.
• Housing Material: UV-resistant PA66 (Nylon 66).
• Contact Material: Gold-plated copper alloy.
• Operating Temperature: -40°C to +90°C.

Connector Details

The MC4-2 uses standard MC4 compatible interfaces. The locking mechanism provides a secure, waterproof connection.

Connector Parts: Housing (Male/Female), Contact Pin/Socket, Seal, Cap (if included).

Locking Mechanism: Push connectors together until a click is heard. To disconnect, press the locking tab and pull apart firmly.

Polarity: Male connector typically carries the positive (+) line. Female connector typically carries the negative (-) line. Always verify with system diagram.

Connecting Solar Panels

For parallel connection of two solar panels to increase current while maintaining voltage.

1. Turn off all system components.
2. Identify the positive (+) and negative (-) leads from each solar panel.
3. Connect the positive lead from Panel 1 to one positive input on the MC4-2.
4. Connect the positive lead from Panel 2 to the other positive input on the MC4-2.
5. Connect the combined positive output from the MC4-2 to the positive input of your charge controller.
6. Repeat steps for negative leads using a second MC4-2 connector for the negative side.
7. Ensure all connections are snapped securely and weatherproof seals are intact.

Tip: Use a multimeter to check for short circuits before connecting to the charge controller.

System Integration

The MC4-2 is designed for integration into grid-tied or off-grid solar systems.

1. Off-Grid Systems: Connect parallel panels to a charge controller, then to batteries and an inverter.
2. Grid-Tied Systems: Connect parallel panels to a string inverter or microinverters.
3. Combiner Boxes: Multiple MC4-2 connectors can be used within a combiner box to manage several parallel strings.
4. Monitoring: Ensure your charge controller or monitoring system can handle the combined current from parallel panels.

WARNING! Do not exceed the maximum current rating of the MC4-2 (30A) or the downstream components. Use appropriate overcurrent protection (fuses/breakers).

Safety Features

IP67 Rating: Protects against dust and temporary immersion. Live Parts Protection: Fully insulated contacts prevent accidental contact. Strain Relief: Prevents cable pull-out and damage to connections. Polarized Design: Prevents reverse polarity connection.

Care & Maintenance

Periodically inspect connectors for dirt, corrosion, or damage. Clean with a dry cloth if necessary.

CAUTION! Do not submerge connectors while the system is live. Do not use solvents or abrasive cleaners. Check seals for cracks and replace if damaged.

Regulatory Information

This product complies with relevant safety and performance standards for photovoltaic connectors. It is designed for use in accordance with the National Electrical Code (NEC) and other local regulations. Samlex Solar is a trademark of Samlex America Inc. For technical support and warranty information, visit www.samlexsolar.com or contact 1-800-561-5885.

Troubleshooting

Replacement: If damaged, replace the entire MC4-2 connector. Do not attempt to repair.

Service: 1-800-561-5885; www.samlexsolar.com