Changes NEN 3140 2026?

There is a draft standard for the new NEN 3140, on which comments can be submitted to NEN, and it will eventually become final somewhere in 2026/2027. However, we have already taken a look. Below is a brief outline of the possible changes. Please note: this is a draft standard and therefore not yet a definitive version of the new NEN 3140.

A selection of the proposed changes includes:

• VOP may remove cables after instruction.
• Appointed persons must possess a safety attitude and resilience.
• Mandatory involvement of the IV in RI&E, V&G plan and TRA.
• Introduction of "securing" and "making ready".
• Clearer PPE requirements within danger zones.
• Mandatory risk assessment prior to work.
• Periodic evaluation of safe operations by the IV.
• New inspection requirement for current distribution in parallel cables.
• Personal lock as self-protection against re-energization.
• Check for de-energization and, if necessary, current-free.
• Expansion of the definition of "separation" to all forms of electrical energy.

The Designations

The designations such as Installation and Work Responsible, Skilled Person and Instructed Person have fortunately not been changed.

Furthermore, in Chapter 6 on Work Procedures, we see that the IV and WV must also discuss and document the method of delivery after work, including the documentation to be delivered. And, Annex F states that the employer must consult the IV when the RI&E, the V&G plan, or TRA is being drawn up, to provide input on possible electrical risks.

Changes for Instructed Person

In article 4.2.105, one task has been added and one has been removed concerning the examples of work performed by the VOP. What has been added to the list of examples is that the VOP, after instruction, is also allowed to remove cables.

Instructed Person (VOP)
Old	New
Replacing lamps	idem
Connecting and disconnecting electric motors	idem
Resetting protective devices	idem
Mounting plugs on cords	idem
Replacing wall sockets and light switches	idem
Mounting lighting fixtures	idem
Inspecting electrical equipment	idem
Inserting/removing certain fuses	idem
Use of work equipment in specific situations	idem
x	Removing cables

Furthermore, it has been added in art. 4.2.116 that designated persons, in addition to their professional competence, must possess the correct safety attitude and resilience.

Securing and Making Ready

Two articles have been added regarding securing and making ready. Securing is essentially the locking that is already incorporated in the 5 Safety Rules and Lock Out, Tag Out procedures, but is now also part of NEN 3140. In addition, the term 'making ready' has been included in art. 3.4.102, which means that the installation is prepared for commissioning after the work has been completed. This was also part of Lock Out, Tag Out but is now clearly articulated in NEN 3140.

Opening cabinets and PPE

In Chapter 6 on work procedures, we find, among other things, a discussion about whether certain PPE should be worn when opening cabinets. For example, before opening a cabinet, you must de-energize the installation (parts). But, if that is not possible:

• You don't need to wear PPE if it has been determined that there is no direct contact hazard and no arc flash hazard.
• You must wear PPE against contact hazard when removing/replacing plastic shields if it has been determined that there is no arc flash hazard.
• And the installation must be de-energized if you are going to remove or replace metal shields where contact hazard or arc flash hazard may exist. In that case, the installation must be de-energized and secured, otherwise this counts as live working.

The necessary protection against arc flashes is determined by the value of the upstream protective devices and can be determined using the table below. This is unchanged except for the reference to Annex B.6.101, which has become Annex B.6, but the content is the same.

Hazard zone and PPE

In the 'old' standard, we had a table (see below) with distances to touchable live parts. These distances have not changed, but it has been clarified which PPE should be used. This was previously a bit of a search between the standard text and the appendices.

We read that the danger zone for electro-technical work is 50 cm, but there are two exceptions:

• When performing measurements, you must always wear insulating gloves within 5 cm of accessible live parts.
  
• And for operational actions, you must also wear insulating gloves within 10 cm of accessible live parts.

Further on in this document, the flowchart is also included, which provides a good insight into when which PPE should be worn.

Portable equipment for earthing and short-circuiting

Art. 3.5.6. was not adopted in the previous round and now apparently is. This concerns portable equipment that can be safely connected to parts of the electrical installation for earthing, short-circuiting, or earthing and short-circuiting. In the note, we read that this refers to earthing components, short-circuiting components, and one or more insulating components such as earthing sticks.

SELV, PELV and FELV circuits

These are circuits that supply a maximum of 50VAC or 120VDC. It has been added that a SELV or PELV circuit is safe under normal circumstances, but that it can be dangerous in damp (crawl) spaces or construction sites.

Risk assessment prior to work

In art. 4.1., which deals with safe operations, it is specified more concretely that a risk assessment must be carried out before starting work, in the vicinity of or on electrical installations and/or work equipment. If this risk assessment shows that the work cannot be carried out as planned, the work must be stopped and the Work Responsible person(s) must be informed immediately. And, if defects or malfunctions occur, the Installation Responsible person must be informed immediately and the necessary measures must be taken immediately.

Furthermore, 4.1.101 states that the installation manager must periodically evaluate safe operation, which is also new.

Working under voltage

In art. 3.4.4., which deals with working under voltage, it has been added that an arc flash can also be caused by falling objects or components. This is indeed true.

Separation

Old	New
Completely freeing an appliance or circuit from other appliances or circuits.	Completely freeing an appliance or circuit from other appliances or circuits to isolate it from all forms of electrical energy.

Electrical work equipment + Earthing kits and working earths

In the 'old' standard, there was already a list of what exactly was considered electrical work equipment, because, as may be known, personal protective equipment (for working on electrical installations) also falls under this, and not only electrical appliances and devices. To this, 'earthing kits' and 'working earths' have been added.

Old	New
Electrical tools	idem
Electrical machines, whether or not permanently connected	idem
Hand lamps and other portable lamps	idem
Current-consuming devices, such as: refrigerators, coffee makers, laboratory equipment, PCs, printers and vacuum cleaners	idem
Portable leads	idem
Portable electrical measuring instruments	idem
Personal protective equipment	idem
Hand tools for live working	idem
Portable switchgear and distribution boards	idem
	Earthing kits
	Working earths

Changes to the inspection of electrical work equipment

The table with maximum resistance values for the protective conductor, for the inspection of electrical work equipment, has not changed, except that it can now be found in Annex R.3.

The values for insulation resistance and leakage current have also not changed, except that they are now in Table R.1 and R.2 (devices with heating elements).

The visual inspection points are also unchanged but are in Annex R.1. The measurements that need to be performed are also unchanged, except for the testing of the RCD (residual current device). In Annex R.4, we read that you must first energize the RCD with a measuring instrument, and only then may you use the test button. The maximum tripping time has remained 300 ms, and it has been added that this tripping time for selective RCDs is between 130ms and 500ms.

It literally states: "The proper functioning of the test button on the RCD can only be checked after the measurement."

We have set up an online training + measuring instrument for this, in which we teach you how to do this.

Determining PPE for electrical work

Furthermore, a flowchart has been included in Annex S, which is clearer than the previous tables in Annex G. The flowchart visually illustrates what was already in the tables, and it certainly adds value.

Supervision

Whether supervision is necessary was regulated in Annex C, and indeed it is still covered in Annex C. However, we have not found any changes in the nature or frequency of supervision.

Drawings

As is known, technical schematics, drawings and the like must be current and available. To this has now been added: 'Data and settings of protective devices', of which the IV must also keep information.

Operating procedures

In article 5.2., the text has been clarified and now reads as follows: "There are two types of operating procedures:

1. operating procedures with switching material intended for that purpose, such as switching on or off the electrical status of an installation or network configuration, but also starting or stopping machines or appliances.
2. separating, disconnecting, or breaking a separation, reconnecting electrical installations, parts thereof, or equipment for the performance of work.

Switching with arc flash hazard

If there is an arc flash hazard during an operating procedure, the new art. 5.2.6 states that only the performers may be present and that they must be properly protected against arc flashes. And, that such work may only be carried out by designated persons. But also that the arc flash hazard can be determined in table 101 and annex B 6, about which more later.

Measuring instrument Category III

In article 5.2, a note has been added stating that when performing measurements on main switchgear and distribution boards, a measuring instrument of at least category III according to the NEN-EN-IEC 61010 series must be used. Further on in annex H, we read that the bare probes of the measuring instrument should preferably not be longer than 4 mm.

Testing electrical installation

In art. 5.3.2, we see that the Instructed Person must also be supervised by a Skilled Person when carrying out tests on the electrical installation. Previously, they could do this independently, but that is now no longer allowed. Incidentally, I don't know any Instructed Person who performs tests on electrical installations, but that's beside the point.

Inspection of electrical installations

The inspection points for electrical installations are included in Annex Q.

Below is an overview of visual inspection; it can be seen that this is largely unchanged, and one point has been added: "Checking the current distribution in parallel-connected cables to determine overloading of individual cables/conductors."

Old	New
a) the necessary drawings are present and contain the correct information;	idem
b) the various (installation) parts are clearly identifiable;	idem
c) any existing damage does not pose a hazard;	idem
d) there are no visible signs of overheating,	idem
e) the electrical equipment is at least in accordance with the installation requirements, such as for example, laid down in the product standards, installation standards and supplier specifications;	idem
f) gangways intended for operation and maintenance and escape routes are sufficiently spacious and easily accessible;	idem
g) connections of visible protective conductors, including equipotential bonding conductors, are in order;	idem
h) the correct protective devices are present and correctly set;	idem
i) the safety circuits are in order;	idem
j) the present voltage indicators and voltmeters function;	idem
k) the electrical installation complies with current usage requirements.	idem
x	checking the current distribution in paralleled cables to identify overloading of individual cables/cores.

The 5 Safety Rules

The 5 safety rules are virtually unchanged, except that in addition to determining de-energization, in certain cases it must also be checked whether the system is current-free.

1. Disconnect.
2. Secure against re-energizing.
3. Verify that the electrical installation is de-energized and, if necessary, current-free.
4. Earth and short-circuit.
5. Shield live parts.

Ad. 1. Disconnect

When disconnecting, the part of the electrical installation must be separated from all power sources. However, it has been added that the neutral must be separated if it does not maintain sufficient earth potential.

Ad. 2. Secure against re-energizing

Some textual changes have been made here, and a separate article on 'remote switching' has been included, but this information was already present in the old standard.

Ad. 3. Verify de-energization

The de-energized state must still be established as close as possible to the work area. And, if earthing systems and the DC side of PV installations (solar panels) are involved, it may also be necessary to determine the current-free state.

The de-energized state must be established for all live parts relative to earth and between the live parts themselves. After disconnection, the installation must be de-energized, taking into account 'residual energy' such as the discharge of capacitors, cables, and frequency converters.

Ad. 4. Earth and short-circuit

The text for earthing and short-circuiting remains unchanged and must still be applied if you cannot ascertain with certainty whether (parts of) the installation will remain de-energized, for example, in the case of an unclear installation, the possibility of an external power supply, or if a line is susceptible to electrical influence. In such cases, you must earth and short-circuit the installation. Further on, it states that equipment for earthing and short-circuiting must be suitable for the highest possible short-circuit current. Furthermore, portable equipment for earthing and short-circuiting can be installed at the workplace, and as we read, this does not need to be short-circuit proof.

Ad. 5. Shield live parts

This point has not changed, so touchable live parts (active parts) must still be shielded.

After de-energizing the installation, the performers must ensure (or have ensured) that the installation is indeed de-energized, and the new standard adds that they must apply 'their own protection against re-energization', which in practice means the application (by those performers) of a personal padlock.

Author: Drs. Richard Winter

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