Is RoHS and EMC compliance enough for a 24V industrial sensor to carry CE Mark?

Question

My company is planning to produce a fork sensor (example). Before starting design, I looked up EU Directives to find if there are any electrical requirements for product safety. First stop was Low Voltage Directive, however it clearly states that products between 75V DC and 1500 V DC are in the scope of the directive.

However, there also is a harmonised standard under LVD which fits for the definition of my product: EN 60947-5-2.

My understanding is that, LVD only cares about product safety, and wants to ensure that nobody gets hurt while device is in operation. The harmonised standard more specifically defines what the product should behave, however not obeying it is not a problem for the product to be in the European Trade Zone.

My questions are:

1. Does a product operating below 75 Volts mean that it is intristically safe (per European Standards)?
2. Is compliance to RoHS and EMC directives enough to mark my product with CE?

Answer 1

My understanding is that, LVD only cares about product safety, and wants to ensure that nobody gets hurt while device is in operation.

Pretty much, yes. It cares about electrical safety, such as preventing humans from direct contact with voltage sources, as well as suitability of materials in regards to fire hazards etc.

LVD does not care about functional safety, such as the application consequences if a switch isn't working correctly. Nor does it care about safety components. That's the Machinery directive. The EN 60947 standards are harmonized below LVD and Machinery directives both.

I would also imagine that shock/vibration requirements apply to the type of product you linked.

Does a product operating below 75 Volts mean that it is intristically safe (per European Standards)?

Not at all, it simply means that the LVD directive does not apply. You still have various application-specific directives though, depending on the nature of the application.

Also notable, if the product contains any form of radio, the RED directive kicks in with a weird rule that, in addition to radio compliance, also enforces LVD directive compliance regardless of supply voltage used.

Is compliance to RoHS and EMC directives enough to mark my product with CE?

Yes, if it has <50VAC or <75VDC supply, no radio and no application-specific directives apply.

For industrial electronics, the EMC directive will point at EN 61000-6-2.

In addition, you need to address the WEEE directive on an organization level, regarding recycling of the product. That part does not need to be in the CE declaration of conformity though.

Answer 2

You are correct when you state that it is about product safety during normal operation, but it is also about safety when things go wrong. For example, it should not catch fire if there is a short circuit, or the circuit is zapped with ESD.

CE marking is not a walk in the park, and because you have not found a specific norm, it doesn't mean that you don't have to apply any. You can spend days researching what norms to apply, but you will still not be 100% certain of what you need.

In my experience, the best thing is to approach one or more testing houses with the details of your design, and ask them for a quote. They will list you all the norms that apply to your design, and you will also get the contacts for when you will need to certify the board. Might as well do it early, so that you don't get a surprise later.