FIRGELLI engineering guide
A waterproof actuator can still fail if the cable end, connector, strain relief or installation path lets water into the electrical system. In the field, many water problems start outside the actuator body.
This guide explains how to preserve the actuator's ingress protection after wiring, especially where the installation includes outdoor equipment, washdown, marine exposure or long cable runs.
Key Engineering Takeaways
- IP rating applies to the tested assembly and installation details matter.
- Cable ends should terminate inside a protected enclosure when water spray or washdown is possible.
- A field splice is not automatically equivalent to an overmolded sealed connector.
- Use strain relief so vibration and cable movement do not pull on seals.
- A drip loop can stop water from tracking along the cable into the connector or enclosure.
- Review choose actuator connectors and wiring connections and prevent water damage to an actuator before finalizing an outdoor wiring layout.
Engineering Guide
1. The weak point is often the cable exit, not the actuator tube
A sealed actuator housing only solves part of the problem. Water can enter through a connector, a cut cable end, a poor splice, a missing rear wire seal, a damaged jacket, or a cable routed so water runs directly toward the connection.
High-pressure spray is especially unforgiving. A connector that survives rain may not survive direct washdown. If the cable end is not protected, pressure can push water into the plug or along the conductor path.
For washdown installations, compare the application against select IP68 waterproof actuators for washdown environments and compare washdown actuator requirements rather than relying on the actuator label alone.
2. Connector sealing rules that hold up in the field
Use connectors rated for the same environment as the actuator. Match the seal material, pin count, current rating, voltage rating and cable diameter. A connector with a good front seal can still leak through the rear if the cable diameter is wrong or the crimp seal is not seated.
Avoid unsupported cable weight. Vibration and repeated motion can flex the cable at the exit point until the jacket cracks or the seal relaxes. Clamp the cable to the frame, leave a controlled service loop and stop the cable from rubbing on brackets.
Use the generate a linear actuator wiring diagram when laying out switches, relays and controllers so the sealed part of the circuit is clear before the machine is assembled.
3. Voltage drop and signal quality are part of the sealing decision
Installers sometimes move the connector far from the actuator to keep it dry. That can help sealing, but the longer cable run increases voltage drop and can make feedback signals more vulnerable to noise. The electrical layout and the sealing layout must be solved together.
Keep high-current motor conductors away from low-level feedback wiring where practical. If power and signal share a route, avoid sharp bends, crushed jackets and loose strain relief. For feedback actuators, shielding and clean grounding become more important as cable length increases.
Check wire size with estimate actuator cable voltage drop and loaded speed before assuming a longer cable is harmless.
4. Actuator example: marine hatch wiring
For a marine hatch, the actuator body may be mounted in a splash zone while the controller is inside a dry compartment. The right answer is usually not an exposed splice under the hatch. Use a sealed connector or continuous cable run into a protected enclosure, create a drip loop before the enclosure, and support the cable so hatch movement does not bend it at the actuator exit.
Where the actuator is regularly exposed to spray, use choose an IP66 actuator for marine hatch lifts as the starting point and confirm the full cable path, not only the actuator tube.
Specification Checks
| Check | What it means | Engineering note |
|---|---|---|
| IP rating | Ingress protection of the tested actuator assembly. | Do not assume field splices maintain the same rating. |
| Connector type | Sealed plug, gland, overmolded cable or field termination. | Field terminations need workmanship control. |
| Cable routing | Path from actuator to controller or enclosure. | Avoid water paths, crush points and unsupported loops. |
| Current rating | Connector and wire ampacity under actuator load. | Check startup and stall current, not only running current. |
| Signal routing | Feedback cable routing and shielding. | Separate from motor power where practical. |
Field Checklist
- Actuator IP rating and connector IP rating
- Cable-end location protected from direct spray
- Connector current and voltage rating
- Rear wire seal sized to cable diameter
- Strain relief within a short distance of the actuator
- No sharp bend at the cable exit
- Drip loop before any enclosure entry
- Glands sealed and tightened to specification
- Power conductors sized for voltage drop
- Feedback wiring routed away from noisy power conductors
Common Mistakes
| Mistake | Why it causes problems | Better practice |
|---|---|---|
| Splicing in the wet zone | A cut cable is joined where it sees spray or condensation. | Move the termination into a protected enclosure or use a sealed connector system. |
| No strain relief | Cable movement loads the actuator seal. | Clamp the cable to structure and leave a controlled service loop. |
| IP rating treated as universal | An IP66 actuator is assumed suitable for every outdoor job. | Match rain, spray, washdown, immersion and corrosion separately. |
Frequently Asked Questions
Does an IP-rated actuator stay waterproof after I cut the cable?
Not automatically. Cutting the cable creates a new termination that must be sealed, supported and protected. The field termination becomes part of the water-resistance system.
What is the best connector for an outdoor linear actuator?
Use a connector rated for the same current, voltage, cable diameter and exposure as the installation. For harsh environments, sealed automotive or industrial connectors are usually better than open screw terminals.
Can heat shrink make a splice waterproof?
Adhesive-lined heat shrink can help, but it is not a substitute for a connector or enclosure designed for the exposure. Vibration, bending and water pressure can still create a leak path.
Should the actuator cable point up or down?
Where possible, route the cable so water does not run toward the connector or into the enclosure. A drip loop below the entry point is often more important than the first few inches of direction.
Does cable length affect actuator performance?
Yes. Longer cable creates voltage drop, especially on 12 VDC actuators with high current draw. Use the estimate actuator cable voltage drop and loaded speed before moving the controller far from the actuator.
How do I protect feedback wires on a linear actuator?
Keep feedback wiring away from motor power conductors where practical, avoid loose grounds and use the controller wiring method recommended for the feedback type. Start with review feedback options for linear actuators if the signal type is not clear.
What should I inspect after a washdown actuator is installed?
Check connector tightness, cable jacket damage, enclosure entries, drip loops, trapped water, corrosion and whether cleaning spray is hitting the connector directly.
