Frameless PV Modules can be a great option for installs, as they:
- Are aesthetically pleasing (slimline appearance).
- Are less expensive than traditional framed PV Modules.
- Have better performance (lack of debris buildup at the edge of the module).
- Have no grounding requirements.
- Are easy to transport and store (due to packaging density and weight).
However, they do come with some concerns, like MLPE mounting and cable management. This article seeks to answer some of those Frequently Asked Questions (FAQ).
How to mount Tigo TS4s if there is no frame
Mounting MLPEs to a frameless module can be tricky, but each TS4 comes with removable clips, for drill mounting to a frame or supporting structure.
How to manage cables
Cable management can be interesting since frameless panels don't offer something to zip-tie the PV Wires to. When this happens, most installers ask these questions:
Can I run the PV Wires in the actual mounting rail?
Do the cables need to be TC-ER (Exposed Run) rated?
Answer: Tigo MLPEs cables are not TC-ER rated (as defined below), but in accordance with NEC 690.31(C)(2), you may run conductors of a TS4 system in any outdoor cable tray (or open rail) whether the cables are TC-ER rated, or not.
"Single-conductor PV wire or cable of all sizes or distributed generation (DG) cable of all sizes, with or without a cable tray rating, shall be permitted in cable trays installed in outdoor locations, provided that the cables are supported at intervals not to exceed 300 mm (12 in.) and secured at intervals not to exceed 1.4 m (4.5 ft)."
📙 TC-ER Definition: Fully annealed bare copper Class B cables in flame retardant PVC/NYLON that are heat and moisture-resistant per UL 62. Primarily used for power, control, signal, communication, and lighting circuits in commercial and industrial environments.
Note: Albeit Tigo's cables are not TC-ER rated, they are TC (tinned copper), where the bare copper conductor is coated with tin to reduce corrosion. This allows for usage in high moisture and dynamic weather environments. The cables are also fire-rated as per UL standard (UL 94).
Other Concerns
When mounting Tigo MLPEs and managing cables, there are some concerns to be aware of:
-
Does the PV Wire length match the height or orientation of the panel?
Some larger PV Modules will exceed the length of the PV Wires, especially if the MLPEs are rail-mounted. Make sure to always refer to the length of cable provided on the datasheet.
-
Are there any sharp edges or drill-mounted objects in the rail that may obstruct or pinch the PV wire?
Any pressure point can cause insulation or compression failures in the wiring of a system. Always make sure that the cables are not bent, crushed, or zip-tied aggressively at any point in the system.