LLT ENGINEERING · Application analysis
Published · Updated
Solar Tracker Waterproof Connectors: Actuator and Harness
On a solar tracker, connector selection starts from the circuit each interface serves, not from the IP rating. Actuator power, feedback and control-box interfaces each carry different voltage, current and cable conditions. Below: the checks that settle each one, and the boundary where the PV DC loop needs a separate selection.
Scope and boundaries
Applies to the auxiliary circuits of single- and dual-axis trackers — actuator power, position and limit feedback, and hybrid control-box interfaces — using the LLT catalog configurations listed for solar tracking. The PV string DC loop, tracker control software and actuator-internal wiring are outside scope; stall current, repeated flexing and cross-brand mating each require project-level verification.
Four Circuits, Four Different Connector Jobs
A tracker presents at least four distinct connection tasks: power to the linear actuator, position and limit feedback back to the controller, the combined power-and-signal interface at the control box, and the PV DC loop between modules, combiner and inverter. On a solar tracker, the right waterproof connector is decided by which circuit the interface serves and whether the joint moves with the actuator — the IP rating alone settles neither question. Treating all four as one purchase is the first selection error, because their voltages, currents, cables and maintenance actions differ.
This article works through the three auxiliary circuits and closes on the DC boundary. The catalog configurations below establish rated voltage, rated current per contact, conductor limits and cable-diameter sealing ranges for specific part numbers; they do not establish stall-current endurance, repeated-flex life, UV service years or cross-brand mating with actuator-supplied connectors.
Sources: LLT selection guide · Technical applicability
Actuator Power: Start, Stall and Regen Set the Load Question
The actuator feed works hardest and moves with the structure, so the routing needs bend allowance across the full stroke, with no tension and no sharp folds at the extremes. List the motor's rated voltage and continuous current, then the starting current, the stall current and any regeneration during back-driving, together with the duty cycle of each event.
Catalog rated current is stated per contact under stated conditions; it is not a stall or arbitrary pulse commitment. If the actuator's stall current exceeds the per-contact rating of a listed configuration, that configuration is not a verified match for the duty, and the correct move is to stop and request temperature-rise verification for the actual load profile. The same stop applies when the actuator maker specifies a mating interface: equal contact count does not make a substitute intermateable.
The two listed wire-to-wire configurations below frame this task. Their conductor figures are published upper limits, and the cable jacket OD must separately fall inside the sealing range of the chosen part — a different check from conductor size.
Sources: LLT public connector catalog · Technical applicability
Position and Limit Feedback: Contact Count Is Not a Protocol
Feedback wiring carries low-level signals, so fix the signal type first — Hall, encoder, analog or a bus — together with supply level, loop count, shielding, grounding and run length. Eight contacts mean eight termination points; they imply no Ethernet or fieldbus capability, because data transmission depends on the complete link. Low-level signals should not be paralleled with motor power on shared contacts.
Among the listed 8-contact wire-to-wire options, the M16 and M19 versions carry IP67 at 110 V and 100 V respectively, while the M12 threaded version at 60 V has its protection field not listed. On an outdoor tracker, an unlisted protection field is a stop-and-confirm item, not a footnote.
Sources: LLT public connector catalog · Technical applicability
Hybrid Control-Box Interfaces: Read Each Contact Group Separately
Power and feedback can enter the box on separate connectors or on one hybrid insert. In a hybrid, check each contact group on its own; the power and signal groups carry independent voltage, current and conductor requirements, and their current ratings must never be added into a machine-level figure. The M25 3+9 hybrid configuration lists power contacts at 300 V and 20 A against signal contacts at 100 V and 5 A, with conductor limits of 2.5 mm² and 0.3 mm² respectively.
The M19 3+5 entry leaves its voltage and current fields unlisted; a series maximum must not be written into an empty field, so treat those values as to-be-confirmed. At the box wall, verify panel sealing, cable-tail sealing and the mating half as one assembly.
Sources: LLT public connector catalog · Technical applicability
Outdoor Exposure: What IP67 Covers and What It Does Not
IP67 denotes dust-tight construction and short-term immersion protection under specified test conditions, and it holds only with the connector correctly mated and locked, seals intact, a cable within the specified outer-diameter range and the installation sealing completed. The unmated half left on the harness during an actuator swap needs its own protection plan. Long-term immersion and high-pressure washdown are different test regimes; if site cleaning involves either, submit water depth, duration, temperature, medium and cleaning method so a configuration with corresponding verification can be selected.
The figures 'UV resistance above 1,000 hours' and 'salt spray above 480 hours' are enterprise-provided performance information tied to specific material and plating combinations and their test records; accelerated hours do not convert into outdoor service years. Request the report for the exact configuration, and judge appearance corrosion and electrical performance criteria separately.
Sources: Technical applicability · IEC 60529 — Degrees of protection provided by enclosures
Moving Joint or Fixed Joint: The Branch That Sets Mounting and Cable
If the connector rides on the moving side of the actuator and flexes through every tracking stroke, cable flexibility, bend routing and strain relief must be verified before any catalog rating is trusted; if the joint stays fixed at the control box, panel cutout, wall thickness and rear-side space become the governing checks instead. An identical electrical answer splits in two here.
On the moving side, support the cable independently so the connector and its terminations are not the load path; state any flex or drag-chain duty, keep a service loop, and place a maintenance disconnect within reach. On the fixed side, pick front- or rear-panel mounting from the part drawing and confirm board thickness, cutout and locking for that part number. In both cases, mate and unmate de-energized unless the configuration is explicitly rated otherwise, and take torque and strip dimensions only from the model-specific document.
Sources: LLT selection guide · Technical applicability · Connection and wiring methods
The PV DC Loop Is a Separate Selection
Tracker auxiliary connectors are not PV module connectors. The DC loop needs the maximum system voltage, loop current, required PV-connector certification and contact protection, plus the specified mating parts, polarity, unlocking tool and cable specification. The catalog lists rear-panel entries such as a 3-pin 600 V 30 A M29 and a 5-contact 600 V 20 A M35, both IP67 for cable OD 10–15 mm, but their AC/DC duty, wiring and locking fields carry to-be-confirmed items. A 'PV' label alone does not qualify a part for series-string high-voltage DC, and cross-brand mating is not claimed. Isolate before maintenance and follow the equipment's specified mating conditions; no live-mating commitment is given.
Sources: LLT public connector catalog · Technical applicability
What to Send Before a Configuration Can Be Confirmed
Selection stays preliminary until the device conditions arrive. Send the items below so the configuration, certificates and test records can be checked per SKU:
- Actuator rated voltage; continuous, starting and stall current; duty cycle of each
- Feedback type, signal count, supply levels, shielding and grounding
- Whether power and signal share one control-box interface, and the group split
- Conductor cross section and jacket OD for every run, with lengths and flex duty
- Which joints move with the tracker and which stay fixed; panel thickness and cutout at box entries
- Exposure profile: orientation, unmated states, temperature range, washdown method, coastal or high-UV site
- Target market and the certification documents required for the chosen SKUs
Sources: LLT selection guide · Technical applicability
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 |
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-M29-30003F2942See catalog for structure · see catalog for wiring | 3 pins | 600 V | 30 A | Rear panel mount | Not listedCable Ø 10–15 mm | IP67Catalog p. 121 |
| LLT-M35-20005F2942See catalog for structure · see catalog for wiring | 5 contacts | 600 V | 20 A | Rear panel mount | Not listedCable Ø 10–15 mm | IP67Catalog p. 122 |
Frequently asked questions
Are solar tracker connectors the same as PV module connectors?
No. Actuator, feedback and control-box interfaces serve auxiliary power and signal circuits; module connectors terminate the string DC loop, which adds DC rating, polarity, contact-protection and PV certification requirements. Select the two separately.
Stall current is above the catalog rating — do I just pick a bigger series?
Not by size alone. Catalog current is a per-contact rating under stated conditions, not a stall or pulse commitment. Submit the stall current, its duration and duty cycle, and request temperature-rise verification for that profile before substituting.
Does an 8-contact connector support Ethernet or a fieldbus?
Contact count alone says nothing about protocol. Eight contacts are eight termination points; bus performance depends on the full link — cable, shielding, impedance and end devices. Define the signal type and transmission requirements first, then check configuration support.
Can a same-pin-count connector replace the actuator maker's original interface?
Not on pin count alone. Intermateability needs matching interface dimensions, locking structure, coding, contact count and pin assignment, confirmed from both drawings; shared series names across brands establish neither mating nor equal performance.