LLT ENGINEERING · Application analysis
Published · Updated
Solar Tracker Waterproof Connectors for Actuator Loops
Choosing waterproof connectors for a solar tracker starts with the actuator loop: motor voltage, continuous, starting and stall current, duty cycle, cable jacket OD and routing under motion. IP67 inline configurations can serve power, feedback and control-box interfaces, but only after each contact group, cable range and maintenance condition is verified.
Scope and boundaries
This article covers auxiliary circuits on solar trackers — actuator power, position and limit feedback, and control-box hybrid interfaces — using the LLT configurations listed on the solar tracking application page. PV module string DC connections, actuator-maker proprietary interfaces, live mating, and long-term immersion or washdown service are outside its scope and each requires separate verification.
Start with the circuit, not the connector series
A solar tracker carries at least four connection jobs: actuator power, position and limit feedback, the control-box interface, and the PV DC loop. This article covers the first three, the auxiliary circuits; the string DC loop follows different rules and is treated as a boundary below. An IP67 inline connector is a workable starting point for a tracker actuator loop only when the motor's continuous, starting and stall currents fit the per-contact rating, the cable jacket OD falls inside the sealing range, and the routing keeps the joint free of tension during motion and maintenance.
Treating every outdoor port as one generic solar connector decision is where mismatches begin: a small multi-contact feedback shell cannot carry motor current, and a family name that sounds photovoltaic does not by itself qualify a part for high-voltage DC strings.
Sources: LLT public connector catalog
Load profile: continuous, starting and stall current
Actuator loops cycle rather than run steadily. Starting current, stall current and any braking or recovery behavior stress the same contact pair, and action duration plus duty cycle set the heating. Catalog values such as 20 A or 35 A per contact apply to the listed configuration; they are not a stall-current or pulse-current commitment. Temperature rise also depends on conductor cross-section, ambient temperature and heat dissipation when several cores carry current at once, so a catalog shortlist is screening, not final approval.
If the actuator cable flexes with the tracking motion or hangs under its own weight at the joint, verify clamping, bending allowance and service access first; if the nameplate stall current exceeds the catalog per-contact rating, stop and request a configuration review instead of moving to a larger series by name.
Sources: Technical applicability · LLT public connector catalog
What the listed configurations actually confirm
For two-pin actuator power, the listed options include an M19 push-lock inline configuration at 250 V and 20 A per contact for cable Ø 6–10 mm, and an M25 at 600 V and 35 A for cable Ø 3.5–13 mm, both IP67 per the cited catalog pages. For feedback, three 8-contact versions span 60 V, 100 V and 110 V at 5 A; the M12 entry lists no protection rating. Eight contacts state a count, not Ethernet or any specific bus capability.
For the control box, the M25 3+9 configuration lists power contacts at 300 V and 20 A and signal contacts at 100 V and 5 A. The M19 3+5 entry leaves those fields not listed; the blanks belong to the part number and must be confirmed rather than filled from series maximums. The catalog configurations cited here confirm contact count, rated voltage, per-contact current and cable OD ranges for specific part numbers; they do not confirm duty cycle, stall-current endurance, mateability with actuator-maker interfaces, or service life under UV and salt exposure.
Sources: LLT public connector catalog · LLT selection guide
Conductor size and cable OD are separate checks
Conductor cross-section is specified per core in mm², with AWG read from the catalog's correspondence, while cable outer diameter is the jacket OD in mm; the two are never interchangeable. The ≤ mm² figure is a published upper limit for screening the conductor; the cable OD must land inside the sealing adaptation range, not merely below the maximum. Cables with identical conductors can differ in OD with core count, insulation and jacket, so both numbers come from the cable specification, not from each other.
Sources: LLT public connector catalog · LLT selection guide
Routing, motion and maintenance access
The actuator moves, so the harness needs bend allowance across full travel, with no tension or sharp-angle bends inside the motion range. The cable requires its own fixing; the connector is not a strain support. Keep a service interface reachable, label power and feedback lines clearly, and re-verify feedback direction after an actuator replacement.
Assembly work happens de-energized: confirm the mating half and pin positions, strip and terminate per the model drawing, keep sealing faces clean, seat the seal, then lock as specified. Torque values and strip lengths come from the model's documentation; do not assume them.
Sources: LLT selection guide · Connection and wiring methods
What IP67 covers — and what it does not
IP67 means dust protection and short-term immersion under specified test conditions, valid when the connector is correctly mated and locked, seals are intact, and the specified cable OD is used. Unmated ports, the far cable end and equipment openings need their own measures.
Long-term immersion and high-pressure washdown are different tests; provide water depth, duration, temperature, medium and cleaning method, and choose configurations with corresponding verification. The stated UV resistance of 1,000 hours or more and salt spray of 480 hours or more are enterprise-provided performance information and cannot be converted directly into outdoor service years. Dust-tightness is not an explosive-atmosphere rating.
Sources: Technical applicability · IEC 60529 — Degrees of protection provided by enclosures
Where this selection stops
Three boundaries end this article's advice. The PV string DC loop needs its own selection: maximum system voltage, loop current, required PV certifications, contact protection, polarity, specified mating parts and unlocking tools. An actuator-maker-specified interface cannot be replaced on equal pin count alone, and cross-brand mateability is not claimed. Unless a configuration explicitly supports it, connectors are mated and unmated de-energized; isolate the drive before maintenance.
Sources: Technical applicability · LLT selection guide
What to submit before a configuration is confirmed
With the following information, a configuration can be screened against the catalog and the remaining items verified per project:
- Interface drawing or mating part numbers; contact counts and wiring definition
- Working voltage and current, including starting and stall values, plus duty cycle
- Cable length and tolerance, jacket OD and material; branch positions, exit direction and end treatment
- Environment: mounting orientation, unmated states, temperature range, cleaning method, cable routing, and required verification items
- Target sales market, so certification coverage such as UL 2238, UL 1977, TÜV, SAA or CE can be checked against certificate scope
Sources: LLT selection guide
Source parameters
| Part no. / structure | Contact count | Rated voltage | Rated current / contact | Mounting method | Conductor cross section / cable outer diameter | Protection / basis |
|---|---|---|---|---|---|---|
| LLT-M19-20002F1031Push-lock · solder | 2 pins | 250 V | 20 A | Wire-to-wire | ≤ 2.5 mm²Cable Ø 6–10 mm | IP67Catalog p. 59 |
| LLT-M25-35002F1031Push-lock · solder | 2 pins | 600 V | 35 A | Wire-to-wire | ≤ 4 mm²Cable Ø 3.5–13 mm | IP67Catalog p. 79 |
Original table and applicability
| Part no. / structure | Contact count | Rated voltage | Rated current / contact | Mounting method | Conductor cross section / cable outer diameter | Protection / basis |
|---|---|---|---|---|---|---|
| LLT-M12-05008F1051Threaded · soldered wire | 8 contacts | 60 V | 5 A | Wire-to-wire | ≤ 0.2 mm²Cable Ø 3.5–6.1 mm | Not listedCatalog p. 20 |
| LLT-M16-05008F1031Push-lock · solder | 8 contacts | 110 V | 5 A | Wire-to-wire | ≤ 0.3 mm²Cable Ø 3.5–8.5 mm | IP67Catalog p. 40 |
| LLT-M19-05008F1031Push-lock · solder | 8 contacts | 100 V | 5 A | Wire-to-wire | ≤ 0.5 mm²Cable Ø 6–10 mm | IP67Catalog p. 59 |
Original table and applicability
| Part no. / structure | Contact count | Rated voltage | Rated current / contact | Mounting method | Conductor cross section / cable outer diameter | Protection / basis |
|---|---|---|---|---|---|---|
| LLT-M19-20305M1031Push-lock · solder | 3+5 contacts | power: V not specifiedsignal: V not specified | power: A not specifiedsignal: A not specified | Wire-to-wire | Not listedNot listedCable Ø 6–10 mm | IP67Catalog p. 65 |
| LLT-M25-20309F1031Push-lock · solder | 3+9 contacts | power：300 Vsignal：100 V | power：20 Asignal：5 A | Wire-to-wire | ≤ 2.5 mm²≤ 0.3 mm²Cable Ø 3.5–13 mm | IP67Catalog p. 79 |
Frequently asked questions
Are solar tracker connectors the same as PV module connectors?
No. Tracker actuator and controller loops carry power, feedback and communication; the module DC loop additionally requires DC ratings, polarity, contact protection and relevant certifications to be verified.
Does an 8-contact connector support Ethernet or a fieldbus?
Eight contacts state a count only. Signal type, levels, shielding, grounding and the complete transmission link must be confirmed with the controller documentation.
Which current rating applies on a 3+9 hybrid connector?
Each contact group separately. The M25 3+9 catalog configuration lists power at 300 V / 20 A and signal at 100 V / 5 A; group ratings are never added into one figure.
Can the actuator maker's original connector be replaced by a same-pin-count IP67 part?
Not on pin count alone. Interface dimensions, locking, keying, pinout and the mating model must match both drawings and pass project verification.