MC4 Solar Connectors and Their Safety in Extreme Conditions
Global Expansion of Photovoltaic Solar Energy
Photovoltaic (PV) solar energy is experiencing significant global growth, reaching into new applications under challenging environmental conditions. Roughly 35% of the Earth’s land area is comprised of desert regions. This reality has spurred the effective utilization of these sparsely populated areas with limited economic value. Prominent examples include the deployment of PV solar plants in the harsh, arid deserts of South America, Africa, southern Europe, and the Middle East.
Requirements for Extreme Environmental Conditions
Electrical installations that operate in ambient temperatures exceeding 70°C or at altitudes above 2000 meters face unique requirements due to the severe climate conditions. It is precisely in these unforgiving locales—such as deserts and high mountainous areas—that large spaces and ideal solar radiation converge to enable highly efficient photovoltaic systems. Stäubli’s MC4 connectors are well-proven in these challenging applications.
Aerial Views and High-Altitude Efficiency
Aerial images reveal extensive arrays of solar modules sprawling across the barren landscapes of places like the Atacama Desert in Chile. These PV installations at high elevations can produce up to 50% more energy compared to those at sea level, benefiting greatly from intense solar radiation and consistently clear skies.
Reliability in Floating PV Systems
Floating PV (FPV) systems are particularly effective in regions where land is scarce, including near-shore locales and inland water bodies. These systems gain advantages from water cooling and the reflection of sunlight off the water’s surface, demanding robust resistance to moisture, salinity, and corrosion to prevent efficiency losses and electrical shorts.
Performance in Agrophotovoltaics
Agrophotovoltaics (APV), or agrisolar systems, not only assist in land-scarce regions but also integrate photovoltaic power generation with agriculture. This can involve setups on animal shelters or greenhouses using PV modules as roofing. Additionally, outdoor PV installations often double as shelters, providing protection from harsh winds or high temperatures and reducing UV damage to plants. Such applications demand enhanced resistance to humidity and, when combined with livestock, resistance to ammonia.
Innovative Connectors for Harsh Environments
For over a quarter-century, Stäubli has been at the forefront in developing connector systems for DC photovoltaic applications, renowned for their high contact quality and durability. The original MC4 products are the first PV connectors that meet the needs of installations in systems where module temperatures reach up to 105°C and are suitable for use at altitudes as high as 5000 meters above sea level. Additionally, these connectors withstand salt mist and ammonia exposure.
Safety Standards in Extreme Conditions
As the market evolves, safety standards such as IEC 61730-1 and IEC TS 63126 are being refined to more precisely address the requirements across different ambient temperature ranges and elevations. These adaptations are vital for ensuring the operational integrity and safety of PV installations under extreme conditions, thus supporting the sustainable and efficient advancement of solar energy globally.
Comparison of MC4 and MC4-Evo 2 Solar Connectors
MC4 and MC4-Evo 2 connectors are pivotal components in photovoltaic system installations, tailored to operate efficiently and safely across various environments and voltage conditions. Here’s a detailed breakdown of their features and applications:
Original MC4 Connectors
- MULTILAM Contact Technology: Ensures outstanding long-term reliability and consistently low contact resistance throughout the product’s lifespan.
- Voltage Compatibility:
- Approved for DC 1000 V under IEC standards.
- Approved for DC 1500 V under UL standards.
- Robust Build:
- Operational ambient temperature range of -40 °C to +85 °C.
- Maximum temperature limit set at 105 °C.
- Protection rating of IP65/IP68 when mated.
- Fire safety class UL94:V-0.
- Special Resistances:
- Ammonia resistance.
- Salt mist spray test, severity level 6.
- Certifications: Includes certifications from TÜV Rheinland, UL, CSA, CQC, and JET.
MC4-Evo 2 Connectors
- High Voltage Optimization:
- Certified for DC 1500 V (TUV / UL / JET).
- Enhanced Features:
- Maximum current rating of 69A.
- Salt mist and ammonia resistance.
- Ambient operating temperature range of -40 °C to +85 °C.
- Upper temperature limit of 115 °C.
- Protection rating of IP65/IP68 when mated.
- Compatibility and Flexibility:
- Compatible with the MC4 connector family.
- Available as both field and pre-assembled connectors.
- Standard crimping tools applicable.
- Broad Certifications:
- Internationally certified with IEC, UL, JET, and cTÜVus.
- UL recognized in accordance with UL6703.
Key Differences
- Temperature Tolerance: The MC4-Evo 2 can withstand temperatures up to 10 °C higher than the original MC4, crucial for operation in extremely hot environments.
- Contact Resistance: The MC4-Evo 2 exhibits slightly lower contact resistance (<0.2 mΩ) compared to the original MC4 (0.25 mΩ), potentially enhancing efficiency in high-capacity systems.
- Certification Scope: Both models boast robust certifications, but the MC4-Evo 2 includes additional certifications tailored for extreme voltage and load conditions.
| Specifications |
MC4 Original (Stäubli) |
MC4 Evo 2 (Stäubli) |
| Contact Technology |
MULTILAM |
MULTILAM |
| Approved Voltage |
DC 1000V (IEC, DC 1500V (UL) |
DC 1500 V (TÜV / UL / JET) |
| Ambient Temperature Range |
-40 °C a +85 °C |
-40 °C a +85 °C |
| Upper Limiting Temperature |
105ºC |
115ºC |
| Protection Degree When Mated |
IP65 /IP68 (1m, 1h) |
IP65 / IP68 (1m, 1h) |
| Protection Degree When Unmated |
IP2X |
IP2X |
| Maximum Contact Resistance |
0.25 mΩ |
<0.2 mΩ |
| Maximum Current |
22.5..39A (depending on models) |
39..53A (depending on models) |
| Ammonia Resistance |
Yes |
Yes |
| Salt Mist Spray Resistance |
Yes, severity grade 6 |
Yes |
| Certifications |
TÜV Rheinland, UL, CSA, CQC, JET |
IEC, UL, JET, cTÜVus, TÜV Rheinland |
| Contact Material |
Copper, tin plated |
Copper, tin plated |
| Insulation Material |
PC/PA |
PA |
| Locking System |
Yes |
Yes |
| Fire Protection Class |
UL94-V0 |
UL94-V0 |
| Connection Type |
Crimping |
Crimping |
| Maximum Operation Altitude |
- |
5000m |
| Additional Certification for Ammonia |
According to DLG |
TÜV Rheinland certified according to 2 PfG 1911/03.2011 |
Conclusion
The choice between MC4 and MC4-Evo 2 connectors will depend on the specific needs of the project, including system voltage, environmental conditions, and regulatory requirements. While the original MC4 is suited for standard applications and has proven reliability, the MC4-Evo 2 offers enhanced capabilities to handle higher voltages and currents, making it ideal for larger and more demanding applications. Both connectors provide a reliable and efficient solution for module interconnection in photovoltaic installations, ensuring optimal performance and enhanced safety in any setting.
