The short answer
Stäubli's MC4 assembly instruction gives typical cable-gland tightening torque of 3.4–3.5 N·m, with a calibrated torque tool.
Plain explanation
In Stäubli MA231 (MC4 PV-KST4 / PV-KBT4), the cable gland is pre-tightened by hand, then finished with the torque tool set while holding the insulator front. Typical values are between 3.4 N·m and 3.5 N·m, matched to the solar cable used. Stäubli recommends calibrating the torque wrench before assembly; NEC 2017 110.14(D) also calls for a calibrated torque tool.
Steps from the source
- Use a calibrated torque tool (not pliers alone)
- Hold the insulator front while tightening the gland
- Aim for about 3.4–3.5 N·m, then confirm the cable type in the instruction
"Typical values are between 3.4 N·m and 3.5 N·m"
Word for word from the source.
Source
Stäubli MC4 assembly instruction MA231 (PV-KST4 / PV-KBT4), Cable gland assembly (ill. 17): typical values 3.4–3.5 N·mwww.staubli.com ↗
Where installers ask this
- Has anyone ever heard of a specific torque value when installing an MC4 connector? (r/electricians)
- reddit.com/r/SolarDIY/comments/1cbgojj/cable_connectors_melted/
- reddit.com/r/solar/comments/tcal4d/how_do_you_crimp_these_mc4_circular_terminals/
General guidance based on the manufacturer's manual or the named source. Always follow the current manual for your exact model and your national code. DC and AC electrical work is for qualified installers only. Not affiliated with or endorsed by any brand named; trademarks belong to their owners.