Last edit: 03/08/2023
THE DOUBT
Can the machinery manufacturer require the user to install a Fuse or a Circuit Breaker to protect its Electrical Equipment? Can he require the user to install a Residual Current Device to protect the user from Indirect Contacts (Fault Protection)?
CONSIDERATIONS
Electrical Energy has two main risks:
– Electric Shock
– Fire
The standard requires the machinery manufacturer to deal with both with the following language:
[EN 60204-1: 2018] 6. Protection against electric shock – 6.1 General
The electrical equipment shall provide protection of persons against electric shock by:
– basic protection (see 6.2 and 6.4), and;
– fault protection (see 6.3 and 6.4).
Basic protection is to prevent Direct Contacts, while Fault protection is to prevent electric shock from Indirect Contacts. Normally, in a TN-S system the magnetic protection opens the fault loop; for that reason, an RCD is usually not required. However, if the manufacturer needs an RCD to open certain fault loops, he cannot delegate its installation to the user. The reason is that the standard requires – the key is "shall provide" – the manufacturer to do that.
Regarding the risk of fire, the language is the following:
[EN 60204-1: 2018] 7.2.3 Power circuits
Devices for detection and interruption of overcurrent, selected in accordance with 7.2.10, shall be applied to each live conductor including circuits supplying control circuit transformers.
If a switch-Disconnector without fuses is used as a General Disconnector, its protection, for example from overload, has to be guaranteed by the fuses or circuit breakers inside the electrical equipment. In other words, the machinery manufacturer cannot ask the user to install a protection on the feeder side of the Panel and, in that way, solve his problem.
CONCLUSION
If you are a user and you just bought a new machinery, you may verify in the Instructions for Use if the manufacturer is requiring you to install, for example, a Residual Current Device Type B. That is something you need to discuss with him, since he is delegating you a safety aspect that he has to take care of. It is like if he were asking you to install a fixed guard on his machinery: without that fixed guard he cannot sign a CE Declaration of Conformity according to the Machinery Directive.
In essence, none of the safety aspects of the Electrical Installation of machinery can be delegated to the user.