Sensors for Export Machinery: CE, IEC 60947-5-2 and the Documents Buyers Ask For

An Indian OEM exporting machinery to Europe, the Gulf or North America takes on responsibility for the compliance of everything inside the machine. The sensors are a small part of that, but they are a part that causes disproportionate trouble — usually because the paperwork was not collected at purchase and cannot easily be obtained afterwards.

This is what to collect, and when.

IEC 60947-5-2: what it actually covers

IEC 60947-5-2 is the international standard for proximity switches. It is not a safety approval and not a certification mark — it is the specification that makes one manufacturer figures comparable with another.

Among other things it defines:

• The standard target against which sensing distance is measured — material, dimensions and shape. Without this, a sensing distance figure means nothing.
• Rated, effective and assured operating distance, and the tolerances between them. These are three different numbers and the gap between them is where field failures live.
• Switching frequency and how it is measured.
• Electrical requirements — supply range, residual current, voltage drop, short-circuit behaviour.
• Marking and documentation requirements.

Accent manufactures to IEC 60947-5-2. The practical value for an exporter is that the figures on the datasheet mean the same thing an inspector expects them to mean, and that a design calculation done against them will stand up.

What to collect, and when

The timing matters more than the list. Collect at purchase, because obtaining documents for a component bought eighteen months ago is difficult and occasionally impossible.

1. Declaration of conformity. The manufacturer statement of which directives and standards the product meets. Required for the machine technical file.
2. The datasheet for the exact variant, not the series. Ratings differ between variants and an inspector will check the one you actually fitted.
3. Material declarations where relevant — RoHS and REACH for European destinations, food-contact declarations for food machinery.
4. Hazardous area certificates if any part of the machine is classified. See specifying intrinsically safe NAMUR loops.
5. Traceability records if your quality system or your customer requires component traceability to a batch.

CE marking and where the responsibility sits

Worth being precise, because it is widely misunderstood.

You CE mark the machine. The sensor manufacturer does not CE mark the machine, and a CE-marked sensor does not make your machine compliant. What component documentation does is support your technical file — it lets you demonstrate that the parts you selected are suitable for the use you put them to.

A sensor supplier who claims their CE mark covers your machine has misunderstood the framework. A supplier who provides clear documentation so you can build your own file is being useful.

Where sensor choice touches machine safety

If a sensor performs a safety function — guard interlock, safe position, emergency stop related — then the relevant standards are the machinery safety ones, and an ordinary proximity switch is generally not sufficient on its own.

Two things to get right regardless:

Fail-safe direction. Specify normally closed for guard and interlock positions, so that a cut cable, a disconnected plug or a failed sensor produces the same signal as an open guard. With normally open, a severed cable is indistinguishable from a closed guard, and the machine keeps running.

Diagnostic coverage. Where the control system must detect a failed sensor rather than merely respond to it, a conventional three-wire sensor cannot help — its off state and a broken wire look identical. NAMUR sensing provides genuine line fault detection, which is one reason it appears on machinery well outside hazardous areas.

Practical points for exporters

Voltage and frequency at destination. A machine going to a 110 V, 60 Hz market needs components rated for it. This catches out AC two-wire sensors in particular — see the A20C range.

Connector conventions. M12 connectors are effectively universal in European machine building. A hard-wired sensor where the customer expects a connector is a small irritation that reflects on the whole machine.

Spares availability at destination. Your customer will ask how they obtain a replacement. Being able to answer properly is part of the sale, and it is worth establishing before the machine ships rather than when the first one fails.

Marking legibility. Part numbers must still be readable after commissioning. A sensor whose label is destroyed by the first clean-down creates a support problem for the life of the machine.

Why domestic sourcing helps here

Three reasons specific to exporters.

Documentation comes from the manufacturer directly, in the timeframe you need it, rather than through an import chain that may not have it.

Variants are available. Destination-specific voltage, connector type and cable length can be specified rather than accepted, which removes adaptation work from every machine you ship.

The part stays available for the service life of the machine. An imported range that gets rationalised leaves your customer — and your reputation — without a replacement.

Accent manufactures in Mumbai to IEC 60947-5-2 and has done since 1985. Tell us the destination market and the documentation your customer requires, and we will confirm what comes with the delivery before you order rather than after.