Tool
MC4 Connectors are crimped, not soldered or clamped. This requires the tool specific to the respective connector system, as the crimp profile and crimping force determine whether the connection remains permanently leak-proof and low-resistance. The tools in this category are exclusively sourced from Stäubli and are designed to work with the connector systems MC4 and MC4-Evo 2.
Which tool for which step
| Work step | Tool in the range |
|---|---|
| Cutting cables to length | PV-WZ-KS cable cutters, cut without crushing the cable |
| Stripping | PV-AZM wire strippers |
| Crimping contacts | PV-CZM crimping pliers for MC4 and MC4-Evo 2 (4, 6 and 10 mm²), PV-ES-CZM crimping insert for 4 to 6 mm², PV-LOC-MC4 locator for 4, 6 and 10 mm²; PV-CZM-BS crimping pliers for MC4 in small quantities (2.5 to 6 mm²) |
| Check contact | Test probes for MC4 (PV-PST) and MC4-Evo 2 (PV-EVO-PST) |
| Tightening and loosening | Assembly spanner sets made of plastic (PV-MS) or metal (PV-MS-PLS), torque spanner set PV-WZ-Torque-Set (3 to 6 Nm) |
If you need everything at once, opt for the tool case for MC4 and MC4-Evo 2. According to the manufacturer, it contains crimping pliers PV-CZM with locators for both connector systems, wire strippers, cable cutters, a torque wrench set, an assembly spanner, both test probes, a release tool and ten protective caps each for plugs and sockets, designed for open crimp contacts with 4, 6 and 10 mm².
MC4 Crimping connectors: what matters
The locator holds the contact in the correct position within the pliers. This ensures that the crimp is positioned in the same place for every contact, resulting in a repeatable finish. The insert and locator must match the conductor cross-section; this is why each tool specifies its range in mm². According to the manufacturer, the crimping pliers PV-CZM are designed for open crimp contacts, not closed ones. The PV-CZM-BS is intended for the original MC4 system and for occasional use.
After crimping, the test pin indicates whether the contact has locked into place correctly. The cable gland is then tightened using the mounting keys. If it is too loose, moisture will enter the housing; if it is too tight, the seal will be damaged. Neither of these issues is visible from the outside of the finished connection, and a poor crimp will heat up under load.
Cables and associated materials
The suitable cables can be found under Solar cables, whilst the other materials are listed under PV installation materials. More information about the manufacturer can be found at Stäubli.
Frequently asked questions about crimping tools
Which crimping pliers do I need for MC4 connectors?
A crimping tool from the connector system with the insert for your conductor cross-section and the appropriate locator. For MC4 and MC4-Evo 2 from Stäubli, tools, inserts and locators are available here in our range.
Can I crimp MC4 connectors using standard crimping pliers?
This is not recommended. The crimp profile and crimping force are tailored to the contact; using a different pair of pliers may create a connection that holds mechanically but heats up under load.
What is the test pin for?
Once inserted, it indicates whether the crimped contact has locked correctly into the connector housing. There is a specific test pin for both MC4 and MC4-Evo 2.