Changes NEN 3140 2026?
There is a draft standard for the new NEN 3140, on which comments can be submitted to NEN and which will ultimately become definitive somewhere in 2026/2027. However, we have already taken a look. Below is a brief explanation of the possible changes. Please note: this is a draft standard and therefore not yet a definitive version of the new NEN 3140.
The Designations
The designations such as Installation and Work Supervisor, Skilled Person, and Instructed Person have fortunately not 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, it can be read in Annex F that the employer must consult the IV person when the RI&E, the V&G plan, or TRA is drawn up to provide input on possible electrical risks.
Changes to Instructed Person
In article 4.2.105, one task has been added and one removed regarding the examples of work carried out by the IP. What has been added to the list of examples is that the IP, after instruction, may also remove cables.
| Instructed Person (IP) | |
| 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 work equipment | idem |
| Installing/removing certain fuse links | idem |
| Use of work equipment in specific situations | idem |
| x | Removing cables |
Furthermore, it has been added in article 4.2.116 that designated persons, in addition to their professional competence, must possess the correct safety attitude and resilience.
Making safe and making ready
Two articles have been added about making safe and making ready. Making safe is essentially locking out, which 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 article 3.4.102, which means that the installation is prepared for commissioning after completion of the work. This was also already part of Lock Out, Tag Out but is now neatly articulated in NEN 3140.
Opening cabinets and PPE
In chapter 6 on work procedures, we find, among other things, a discussion about whether you should wear certain PPE when opening cabinets. For example, before opening a cabinet, you must de-energize the installation (parts). But, if that is not possible:
- You do not 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 where 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 made safe, otherwise this counts as live working.
The necessary protection against arc flashes is determined by the value of the upstream protective device(s) and can be determined using the table below. This has not changed except for the reference to annex B.6.101, which has become annex B.6, but is substantively the same.
Hazard zone and PPE
In the 'old' standard, we had a table (see below) with distances to live parts that could be touched. These distances have not changed, but it is now clearer which PPE must be used. It was a bit difficult to find that information between the standard text and the annexes.
We read that the hazard zone for electrotechnical 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 operating procedures, 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
Article 3.5.6 was not adopted in the previous round and apparently is now. 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 remark, we read that this concerns 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 conditions, but that it can be dangerous in damp (crawl) spaces or construction sites.
Risk assessment prior to work
In article 4.1., which concerns safe operation, it has been more concretely stated that a risk assessment must be carried out before starting work, in the vicinity of or on electrical installations and/or work equipment. If the risk assessment shows that the work cannot be carried out as planned, the work must be stopped and the Work Supervisor(s) must be informed immediately. And, if defects or malfunctions occur, the installation manager must be informed immediately and the necessary measures must be taken without delay.
Furthermore, it has been included in 4.1.101 that the installation manager must periodically evaluate safe operation, which is also new.
Live working
In art. 3.4.4., which deals with live working, it has been added that an arc flash can also be caused by falling objects or components. That is indeed the case.
Separating
| Old | New |
| Completely isolating an appliance or circuit from other appliances or circuits. | Completely isolating an appliance or circuit from other appliances or circuits to isolate it from all forms of electrical energy. |
Electrical work equipment + Earthing sets and temporary earthing equipment
In the 'old' standard, there was already a list of what exactly was meant by electrical work equipment because, as is perhaps known, personal protective equipment (for working on electrical installations) also falls under this, and thus not only electrical appliances and equipment. To this, 'earthing sets' and 'temporary earthing equipment' have been added.
| Old | New |
| Electrical tools |
idem |
| Electrical machines, whether or not permanently connected | idem |
| Hand lamps and other portable lamps | idem |
| Power-consuming appliances, 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 controlgear | idem |
| Earthing sets | |
| Temporary earthing equipment |
Changes to inspection of electrical work equipment
The table with maximum resistance values for the protective conductor, for inspection of electrical work equipment, has not changed, except that it can now be found in annex R.3.
Also, the values for insulation resistance and leakage current have not changed, only they are now in tables R.1 and R.2 (appliances with heating elements).
The visual inspection points are also unchanged but are in Annex R.1. Likewise, the measurements that must be performed are unchanged, except for the testing of the residual current device (RCD). There we read in Annex R.4 that you must first flow current through the RCD with a measuring instrument and only then may use the test button. The maximum tripping time has remained 300 ms, and it has been added that for selective RCDs, this tripping time is between 130 ms and 500 ms.
It literally states: "The correct 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 represents what was already present in the tables, but certainly adds value.
Supervision
Whether supervision is necessary was regulated in Annex C, and indeed, it is still included in Annex C. However, we have not found any changes in the nature or frequency of supervision.
Drawings
As is known, technical diagrams, drawings and the like must be current and available. To this, it has now been added: 'Data and settings of protective devices', of which the IV person must also keep information.
Operating procedures
In art 5.2. the text has been included more clearly, it now reads as follows: "There are two types of operating procedures:
- operating procedures with switchgear intended for this purpose, such as switching the electrical status of an installation or network configuration on or off, but also starting or stopping machines or appliances.
- separating, disconnecting or lifting 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, we read in the new art. 5.2.6 that only the performers may be present and that they must be properly protected against arc flashes. And, that such work may only be performed by designated persons. But also that the arc flash hazard can be determined in table 101 and annex B 6, about which more will follow.
Measuring instrument Category III
In article 5.2. it has been added as a remark 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 of electrical installations
In art. 5.3.2, we see that the Instructed Person must also be under the supervision of a Skilled Person if he carries out tests on the electrical installation. Previously, he was allowed to do this independently, but this is now no longer the case. Incidentally, I don't know any IP who carries out 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 virtually unchanged and that one point has been added: "The check of the current distribution in parallel connected cables to determine overloading of the 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 cause danger; | idem |
| d) there are no visible signs of overheating, | idem |
| e) the electrical equipment is at least in accordance with the installation requirements, as for example laid down in product standards, installation standards and supplier specifications; |
idem |
| f) the aisles intended for operation and maintenance and the escape routes are sufficiently wide and easily accessible; | idem |
| g) the connections of the 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 is appropriate for the current usage requirements. | idem |
| x | the control of current distribution in parallel connected cables to determine overloading of individual cables/conductors. |
The 5 Safety Rules
The 5 safety rules are virtually unchanged, except that in addition to determining de-energization, in some cases it is also necessary to check whether the system is current-free.
- Disconnect.
- Secure against re-energization.
- Verify that the electrical installation is de-energized and, if necessary, current-free.
- Ground and short-circuit.
- Protect active 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-energization
Some textual shifts 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 determined as close as possible to the workplace. And, if earthing systems and the DC side of PV installations (solar panels) are also involved, it may be necessary to also determine the current-free state.
The de-energized state must be determined for all active parts relative to earth and between the active 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. Ground and short-circuit
The text for grounding and short-circuiting is unchanged and must still be applied if you cannot ascertain with certainty whether (parts of) the installation will remain de-energized, such as in the case of an unclear installation, or if an external power supply is possible, or if a line is electrically susceptible. In such cases, you must ground and short-circuit the installation. Further on, it states that equipment for grounding and short-circuiting must be suitable for the highest possible short-circuit current. Furthermore, at the workplace, portable equipment for grounding and short-circuiting can be installed, and as we read, it does not need to be short-circuit resistant.
Ad. 5. Protecting active parts
This point has not changed, so accessible live parts (active parts) must still be protected.
After de-energizing the installation, the operatives must satisfy themselves (or be satisfied by others) 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 operatives) of a personal padlock.
Author: Drs. Richard Winter
If you wish to stay informed, please register using the form below.