A temporary electrical installation is often used at events, construction sites and emergencies. But before you start using your installation, an inspection is required by law. Such an inspection prevents unsafe situations and ensures that you meet all legal requirements. What exactly is waiting for you? And how do you ensure that your temporary installation immediately passes the inspection? This article lists all the inspection points, practical preparation tips and the most common rejection points.
What does an inspection of a temporary installation entail
A temporary electrical installation must comply with the Dutch Installation Decree and the NEN 1010 and NEN 3140 standards. Inspectors hereby check both the safety and technical condition of the installation. The goal is to eliminate possible risks (such as fire or electrocution hazards).
Pre-inspection or post-inspection?
- Preliminary: Immediately upon construction of the temporary installation, you can request an initial inspection. The inspector will check if the design and implementation meet the standard.
- Retrospective: A second inspection often follows after commissioning, checking whether there have been any changes in practice.
Checklist inspection points temporary installation
Inspectors use a set list of checkpoints. These are based on legal requirements and standards. Below you can read what to look for.
1. General state of the installation
- Soundness: Are all components (cables, plugs, junction boxes) in good condition with no visible damage?
- Safety: Is the installation properly completed? Are there no loose wires or faulty connection points?
- Marking: Are all groups, cables and connection points clearly labeled and traceable?
2. Grounding and circuit breaker
- Ground fault circuit breakers: Are ground fault circuit breakers present and functioning? This is often tested with a test button.
- Grounding resistance: The grounding device is measured. The value must be within the standard (maximum 1667 Ω at 30 mA ground fault).
- Protection against indirect touching: Are metal parts that may be energized protected or grounded?
3. Cables, pipes and wire bridges
- Fastening: Are cables properly secured and protected from damage?
- Protection: Do cables not run over sharp edges or through high-traffic locations without additional protection?
- Cross-sectional area: Cables used must be suitable for the current rating (amperage) of the connected equipment.
4. Divide, switch and secure
- Group distribution: Are the groups correct and logically distributed?
- Circuit breakers: Are installation circuit breakers present and correctly set for power?
- Overload protection: Is an appropriate fuse or circuit breaker installed throughout?
5. Sockets, couplers and connections
- Socket type: Are only splashproof (IP44/IP54) variants used for outdoors?
- Damage: Are outlets, junction boxes and plug connections free of damage or corrosion?
- Safety: Are there no open connections or missing covers?
6. Additional measures in wet or demanding environments
- Rubber cables (H07RN-F): Are rubber cables used in damp areas or outdoors?
- Shielding: Are provisions made to keep water or moisture out of electrical boxes?
7. Documentation and inspection reports
- Schematics: Is an installation or single-wire diagram available for review?
- Previous inspections: Are previous inspection reports available?
- Operating Instructions: Is it clear who is responsible for managing the installation?
Here’s how to prepare for an inspection
Good preparation increases your chances of passing the inspection in one go. Take the following tips to heart:
- Have all installation work performed by
Is your temporary plant ready for inspection checklist for a successful inspection?
Safety and continuity are central to temporary electrical installations. Whether it’s a construction site, event, or temporary facility during a renovation-an inspection is essential to comply with the Dutch standard (NEN 1010, NEN 3140) and to reduce risks. But when is your temporary installation really ready for inspection? This blog offers a complete checklist, insight into what inspectors look for, and practical tips to avoid rejection points.
You can expect this
- The role and timing of an inspection for temporary installations
- What specifically do inspectors pay attention to during the inspection?
- How do you prepare your installation step by step?
- Most common rejection points
- Prevention tips to expedite approval
Why inspection of temporary installations is mandatory
Every electrical installation, temporary or permanent, must comply with legal safety requirements. Certainly temporary installations at events, construction sites or festivals change location or set-up quickly, creating additional risks of faults or defects. A (re)inspection is then legally required before the installation can be put into use. This prevents fire hazard, injury by electrocution and expensive downtime.
What inspectors check during a temporary plant inspection
Inspectors work using clear standards and checklists. These are key points they always look at:
1. Documentation and diagrams
- Installation diagrams provided: Clear drawings and descriptions of all connected groups, distribution boxes and circuits.
- Log and inspection reports: An updated logbook of previous inspections, maintenance and incident records.
2. Protection against electric shock
- Grounding present and tested: Ground stake or ground rail installed and measured as per requirement;
- Peripheral earth and earth leakage switches: Peripheral earth and working earth leakage switches (max 30 mA) per terminal group.
3. Overload and short circuit protection
- Circuit breakers and fuses correctly sized: In temporary installations, proper selectivity and tuning are especially important because of the often changing load;
- Fuses connected correctly: Visible and accessible group boxes, no overrides or unsafe adjustments anywhere.
4. Visual inspection of equipment and cabling.
- No damaged cables or plugs: Check for cut or melt damage, visible wire breaks or loose connections;
- Proper use of cables and extension cords: Cables correctly protected from mechanical stress and moisture;
- Approved junction boxes and connection materials: Use only materials with CE marking and valid inspection.
5. Tests and measurements
- Earth diffusion resistance ≤ 166 Ω (depending on installation type);
- Insulation resistance (≥ 1 MΩ at 500V);
- Passage of protection line (continuity ground);
- Circuit breaker operation tested;
Inspectors perform measurements with calibrated measuring equipment and compare the results with standard values.
Roadmap for smooth preparation
Preparing your facility for an inspection does not have to be complicated if you follow these steps:
Step 1. Gather all documentation
Start by updating installation and connection drawings, the logbook and any previous inspection reports. Poor or missing documentation is one of the most common reasons for rejection.
Step 2. Perform a visual inspection
Physically check all cables, plugs, junction boxes and junction boxes:
- Check for damage, loose connections and incorrect protection rating (IP rating).
- Test that all moving parts (valves, caps) are functioning properly and not missing.
Step 3. Measure important values after
Perform basic measurements yourself with appropriate measuring equipment:
- Measure the operation of ground fault circuit breakers (test button).
- Check ground spreading resistance and insulation resistance.
- Check the continuity of the ground line.
Step 4. Check inspection status of equipment
- Only materials, distribution boxes, cables and switches that are still within valid inspection periods may be used.
- Visibly label the inspection date on distribution boxes, cables and frequent connection points.
Step 5. Clean up the installation in a structured way
- Keep cables out of walkways, avoid tripping hazards.
- Limit the number of distribution boxes to the necessary minimum; eliminate cables as much as possible.
Step 6. Schedule a trial inspection
Have an experienced installer or expert check your setup for the most important rejection points before the official inspection. This prevents surprises and unnecessary delays.
Common rejects and how to avoid them
Even the most experienced installer encounters them. These are the top 5 rejects in temporary installations:
Insufficient or missing grounding
- Always use an approved ground pin or check the existinge facilities for operation before installation.
Damaged or inappropriate cables
- Use only rubber or PUR cable with steel reinforcement for harsh conditions; replace damaged cables immediately.
Wrongly connected RCD
- Always test with the test button, verify that each terminal group is properly protected.
Incorrect or missing documentation
- Ensure that installation diagrams, inspection reports and manuals are always present and up to date
Loose or incorrect connections in distribution boards
- Check for loose screws, wire breaks or unused openings.
Additional tips for inspection and testing
- Prepare materials for the inspector (measuring points, distribution boxes).
- Communicate in advance about unusual situations (e.g., exceptions due to site layout).
- Schedule the inspection well in advance of commissioning to avoid reinspections due to minor defects.
- Always have changes recorded immediately in the log after adjusting the installation.
This is how you effortlessly pass a positive inspection
Thorough preparation is important to get your temporary electrical installation approved quickly and without problems. By ensuring accurate documentation, a thorough visual inspection, preventive measurements and the use of approved equipment, you significantly reduce the risk of rejection.
Are you active on a construction site, event site or are you looking for support with a solution such as temporary heating of a large space? Van Lieshout Elektra will gladly think with you about a safe and efficient temporary installation. As an experienced electrical installation company in Helmond, in addition to full inspection support, we also provide customized solutions, such as a customized switch box, tailored to the load and operating environment.
Would you like to know more about the inspection of temporary installations or are you looking for guidance in preparation and handling? Then feel free to contact us. We will help you quickly and professionally.
