Short answer: Only under very specific conditions—and only if both connectors are made by Staubli.
Improper mating of PV connectors is one of the leading causes of system failures, fires, and service calls. It’s critical that all installers understand the rules when connecting modules to Tigo TS4 products.
The Code: NEC 690.33(C)
The National Electrical Code (NEC) is very clear:
“Connectors of the same type shall be permitted to be intermateable where listed for intermatability.”
In plain English? You can only connect different PV connectors if:
- They are the same type, and
- They are UL or TÜV listed as compatible with each other.
This is where it gets tricky.
MC4 vs. MC4-Evo2: What’s the Difference?
Tigo TS4 devices use Staubli MC4 connectors. Many newer solar modules now ship with Staubli MC4-Evo2 connectors.
Although they look similar and can physically mate, they are not the same product:
- Different materials and locking mechanisms
- Different voltage ratings (MC4 is 1000V or 1500V, Evo2 is always 1500V)
- Slightly different specs and tolerances
But, because Staubli manufactures both, they’ve submitted them for cross-compatibility testing and received TÜV and UL certification under specific conditions.
When It Is Allowed
Staubli has confirmed the following:
“MC4 and MC4-Evo2 connectors are considered the same type when both are manufactured by Staubli, and the cable size is 4mm² or 12 AWG. The pair is TÜV and UL certified for intermatability under those conditions.”
So, if you're connecting a Tigo TS4 (with Staubli MC4) to a Staubli MC4-Evo2 connector on a module, and:
- Both connectors are genuine Staubli products
- The wire size is 4mm² or 12 AWG
- You respect the lower-rated voltage/current of the two connectors
Then the connection is allowed.
When It’s Not Allowed
Any of the following conditions make the connection unsafe and non-compliant with code:
- The connectors are from different manufacturers (even if labeled “MC4-compatible”)
- The wire size doesn’t match
- The connectors are forced together and not truly intermateable
- One or both connectors are unlisted, counterfeit, or off-brand
Tigo does not certify or warranty connections made between TS4 devices and non-Staubli connectors, even if they are physically similar.
Best Practices for Installers
- Always verify the brand of both connectors.
- Use Staubli-to-Staubli only (MC4 ↔ Evo2).
- Confirm the wire gauge is 4mm² (12 AWG).
- Use the lower-rated voltage and current if mixing MC4 with Evo2.
- When in doubt—replace the module connector with a Staubli MC4.
Why This Matters
Improper connector mating is one of the most common causes of:
- Thermal events
- Arcing and fire
- Failed inspections
- System downtime and service calls
The safest and fastest install is one that follows both manufacturer guidance and NEC code.
Still Have Questions?
If you're not sure what connectors you’re dealing with or need help identifying them, reach out to Tigo Technical Support.
Staubli Reference: