Aluminium Conduit Profile 40×80 mm Large Cable Duct Enclosure

OEM / ODM Available Free Sample Available ISO 9001:2015 EN 755-9 RoHS REACH

40 x 80 mm aluminium conduit profile in 6063-T5 with a 66 x 11 mm internal cavity, a 1.5 mm wall and a weight of about 1.15 kg/m. Wide enough to keep power and signal cables physically separated in one duct on a 40 series frame.

Wholesale Price $2.40 - $4.10 / m per m

Material	Aluminium
Alloy Grade	6063-T5
Temper	T5
Section Size	40 x 80 mm
Slot	Base has 3 x 4 mm mounting holes for T-slot nut fixing to a 40 series profile
Length	6 m stock, cut to drawing to +/-0.5 mm
Tolerance	EN 755-9 / GB/T 6892, wall +/-0.15 mm
Surface	Mill finish / clear anodised / black anodised
MOQ	800
Lead Time	18-28 days after deposit, longer for a custom divider rib die
Loading Port	Shanghai / Ningbo
Supply Ability	500 t per month of wide conduit and duct profiles
Payment Terms	T/T 30% deposit + 70% before shipment \| L/C at sight
Trade Terms	FOB \| CIF \| EXW
Certifications	ISO 9001:2015 \| EN 755-9 \| RoHS \| REACH

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Large cable duct · 40 x 80 mm

A 40 x 80 mm aluminium conduit profile is an extruded duct with an 80 mm wide by 40 mm deep outside envelope, a 66 x 11 mm internal cavity, a wall of about 1.5 mm and a weight of about 1.15 kg/m in 6063-T5. It mounts to the slot of a 40 series profile with T-slot nuts and takes a snap or gasketed cover. The reason to use it rather than two 40 x 40 ducts is that its 66 mm of usable width lets power and signal cables share one duct while staying physically apart, which is what keeps switching noise out of a control signal. It sits at the wide end of the aluminium conduit profiles range, alongside the narrower sections used for single-service routes.

Two things decide how it is used. The first is separation: power and signal cables should not run side by side in the same air space, because a variable frequency drive or a contactor couples noise into a signal cable by induction, and the fix is distance or a grounded metal barrier rather than a thicker insulation. The second is support: a 40 x 80 duct is a long, shallow section, and a run that spans between widely spaced supports sags, which shows as a wavy cover line and eventually as a loose cover. Support it every 1.5 m as a working default, and closer where the run also carries a device.

40 x 80 mm conduit section: 80 x 40 mm envelope, 66 x 11 mm cavity, 1.5 mm wall, three 4 mm mounting holes, about 1.15 kg/m in 6063-T5.

Why power and signal cannot share the same air space

Noise gets from a power cable into a signal cable in three ways: by capacitive coupling between conductors that run close together, by inductive coupling from the magnetic field around a current-carrying cable, and by a shared return path where the two circuits use the same earth conductor. All three depend on distance, and two of the three are greatly reduced by putting a grounded metal barrier between the cables rather than by changing the cable itself.

In practice the rule is to separate power and signal by at least one cable diameter where they run parallel, and to increase that distance as the power cable gets bigger or as the current becomes switched or pulse-width modulated. Where a long parallel run is unavoidable, the barrier matters more than the distance, which is exactly what a wide duct with an internal divider is for.

Cable type in the duct	Minimum separation	Barrier needed
Extra-low voltage signal, analogue	One cable diameter	Recommended for runs over 2 m
Digital control and encoder cable	One cable diameter	Recommended, and ground the shield at one end
Motor cable from a VFD	Two to three cable diameters	Yes, grounded metal barrier
Mains power, lighting and socket circuits	One cable diameter	Recommended
Safety circuit wiring	Separate duct where possible	Yes, and keep it out of the power duct

Shielding is not a substitute for separation. A screened signal cable still couples noise if it runs alongside a motor cable for metres, because the screen carries the interference as a common-mode current. Fix the geometry first — distance or a grounded divider — and treat the screen as a second line of defence.

Four ways to make the divider

The 66 mm of usable width in this duct can be split in four ways, and the choice depends on whether the barrier has to be earthed, whether cables have to be added later, and how much width the power side needs.

Internal rib in the extrusionThe cleanest answer: the die is drawn with a rib down the middle of the cavity, so the divider is part of the section. It gives a fixed split, cannot come loose, and costs nothing to install. It is a custom die feature, so it is specified at the enquiry stage rather than added later.

Clip-in divider stripA separate aluminium or plastic strip that clips into grooves in the cavity walls. The duct is bought standard and the divider is added, which lets the split be changed on a future order. Less rigid than an extruded rib, and it must be earthed separately if it is metal.

Two ducts side by sideTwo 40 x 40 ducts mounted on the same frame member, one for power and one for signal. This gives the greatest separation and the easiest future access, at the cost of two covers and twice the mounting work.

Grounded metal barrierWhere the noise source is a VFD or a large contactor, the divider has to be bonded to earth to act as a screen. Bond it to the frame at both ends with a short, wide connection, because a long thin earth tail has enough impedance at the switching frequency to make the barrier useless.

Span, deflection and support spacing

A 40 x 80 duct is shallow in one direction and wide in the other, so it is much stiffer against a vertical load than its 40 mm depth suggests, and much less stiff against a side load. Cable weight is light, so deflection under the cables alone is small; the reasons to support a long run are to keep it visually straight, to stop it vibrating on a machine, and to carry any device mounted on it. The figures below are planning values for a simply supported span under a 3 kg/m cable load, with a second moment of area of about 10 cm4 and a modulus of 70 GPa.

Support spacing	Mid-span deflection at 3 kg/m	Comment
1.0 m	about 0.05 mm	Rigid, no visible sag, use where a device is mounted
1.5 m	about 0.3 mm	Recommended default for a cable-only run
2.0 m	about 0.9 mm	Acceptable but the cover line starts to show a wave
2.5 m	about 2.1 mm	Visible sag, avoid unless the run is hidden
3.0 m	about 4.3 mm	Not recommended for a visible or vibrating run

Two things change the picture. A run that also carries a socket outlet, a junction box or a small device is no longer carrying cable weight alone, so treat it as a loaded beam and halve the spacing. A run on a machine with vibration should be supported closer than the deflection figure alone suggests, because vibration loosens a cover long before the duct visibly sags.

40 x 80 or 40 x 40

The two sizes are not alternatives; they do different jobs in the same frame. A 40 x 40 duct is a single-service route: signal wiring along a workbench, control cable inside a cabinet, or a short run to a device. A 40 x 80 duct is used where two services have to share a route, where the cable count is high, or where the duct is also a visible frame member and a single wide cover reads better than two narrow ones.

Question	40 x 40 duct	40 x 80 duct
Cavity	32 x 8.2 mm, about 262 mm2	66 x 11 mm, about 726 mm2
Services	One, signal or power	Two, separated by a divider
Weight	about 0.62 kg/m	about 1.15 kg/m
Cover line on a visible frame	Narrow, needs two runs for two services	One wide cover reads as a single detail
Typical use	Workbench and cabinet wiring	Long frame runs with power and signal

Where both sizes appear on the same frame, the usual arrangement is a 40 x 80 duct along the main horizontal run carrying power and signal, and 40 x 40 ducts dropping from it to the individual stations. Both mount on the same 40 series profile slot with the same T-slot fastening elements, so a mixed run needs no special parts, and covers and end caps come from the profile accessories range. Where the run is fixed to a bench or a platform, the brackets and feet come from the floor elements range, and the sections themselves are part of the wider aluminium sections we extrude.

Alloy, finish and how it is supplied

The section is extruded in 6063-T5, in mill finish, clear anodised or black anodised. Mill finish is what most industrial frames use; anodising is chosen where the duct is visible or where it sits in a washdown area and has to be wiped clean. Cutting, drilling and any divider groove machining are done before the finish is applied, so give the entry positions, the mounting holes and the divider requirement with the cut list. Coloured runs are processed as anodised aluminium profiles in one batch, and any machining is done on CNC machining centres.

Automation cell frame and workbench built from 40 series aluminium profiles, with wide cable ducting run along the main frame members — A 40 x 80 duct is used where a frame has to carry two services along one route: the 66 mm of usable width takes a divider, so power and signal share the run without sharing the air space.

Frequently asked questions

Why do power and signal cables need to be separated in one duct?

Because noise couples from a power cable into a signal cable by capacitance, by inductance and through a shared earth path, and all three depend on distance. Separate them by at least one cable diameter where they run parallel, and use a grounded metal barrier for long runs or where the power cable is fed from a VFD.

How do I make the divider inside a 40 x 80 duct?

Four ways: an extruded rib drawn into the die, a clip-in divider strip, two ducts side by side, or a grounded metal barrier. The extruded rib is the cleanest and is specified at the enquiry stage; a clip-in strip lets the split change on a later order.

How often should a long duct run be supported?

Every 1.5 m as a working default for a cable-only run. Halve that where the duct also carries a device, and support it closer on a machine with vibration, because vibration loosens a cover long before the duct visibly sags.

When should I use 40 x 80 rather than 40 x 40?

When two services have to share one route, when the cable count is high, or when the duct is also a visible frame member and one wide cover reads better than two narrow ones. A 40 x 40 duct is for a single service or a short drop to a device.

Can you supply the duct with a divider rib?

Yes, as a custom die feature, normally from about one tonne per section. Send the cable schedule and the split you need and we will confirm the rib position and whether the divider should be earthed.

Send the cable schedule and the span, not only the duct size

Tell us which services have to share the route, whether the power side is fed from a VFD, and how far the run spans between supports. We will confirm the divider arrangement, whether it should be bonded to earth, and the support spacing, then quote the extrusion, the cutting, the drilling, the divider and the finish as one package with FOB pricing, supplied with covers and end caps bagged by assembly.

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