SiteIt's 4am. The case erector has stopped and the HMI says drive fault. Your night fitter is a mechanical fitter, and a good one. They've got the panel door open and a meter in their hand. The shift manager wants to know if it's "just a fuse".
You get the call at home. The question on the phone is how long. The question you should be asking is different. Should that person be in that panel at all?
Most managers file the Electricity at Work Regulations under the electrician's job. The duties land on you as well. Most of them are about people and maintenance, and very few are about paperwork.
Who the duties land on
Regulation 3 puts the duty to comply on every employer and self-employed person, so far as the duties relate to matters within their control (regulation 3). It puts the same kind of duty on employees for the things they control. HSE's guidance on the Regulations, HSR25, says this "recognises the level of responsibility" that many people in the electrical trades take on (HSR25, paragraph 55).
So the duties are shared. The site carries them. So does the sparky with the screwdriver, and so does a contract electrician you bring in for the night. How much each person holds depends on how much control they have over the job.
Some duties have no get-out
Many duties carry the words "so far as is reasonably practicable". That means weighing the risk against the money, time or trouble of controlling it. Some duties don't have those words. HSR25 calls them absolute. They "must be met regardless of cost or any other consideration" (HSR25, paragraph 58).
Even the qualified duties are close to absolute in practice. The risk is often death. The precautions are often simple and cheap, like insulation. So HSE's view is that the duty "approaches that of an absolute duty" (HSR25, paragraph 60).
For a set list of regulations there's one defence*. You have to prove you "took all reasonable steps and exercised all due diligence" to avoid the offence (regulation 29, HSR25). The list includes the rules on isolation, live work and competence.
In practice, due diligence means records. If you can't show the training, the isolation procedure and the maintenance, you can't show the steps.
Maintained, and working safely
Regulation 4 is the broad one. Systems must be built to prevent danger. They must be maintained "as may be necessary to prevent danger". Work on or near them must be done in a way that doesn't create danger. Any kit provided to protect people, such as insulating mats or gloves, must be suitable, maintained and properly used (regulation 4).
HSR25 fills in the maintenance side. Inspection and, where needed, testing are part of any preventive maintenance programme. How often is your call, using the maker's guidance and your own experience (HSR25, paragraph 68). Records aren't a legal requirement. But HSR25 is blunt about life without them: "dutyholders cannot be certain that the requirement for maintenance has been complied with" (HSR25, paragraph 69).
For the wiring, that means periodic inspection and testing, which we cover in inspecting and testing fixed wiring. For plug-in kit it means a sensible regime, and that isn't always a sticker on everything. See what PAT testing actually requires.
Dead is the default
Regulations 12 to 14 deal with isolation and live work. You need a way to cut off the supply and isolate the kit. Kit made dead must be kept dead while the work goes on. Live work is only allowed when it's unreasonable for the kit to be dead, reasonable to work on it live, and suitable precautions are in place (regulation 14).
HSR25 says it's preferable to make conductors dead before work starts, and to prove them dead at the point of work. The tester itself should be proved "immediately before and immediately after testing the conductors" (HSR25, paragraph 72). We've set out the steps in lock off, tag out, prove dead.
Back to 4am. Fault-finding on a drive often needs some live testing. That can be allowed if it's planned and the three tests are met. "Production needs it back" is none of them.
Competence is the one that bites at night
Regulation 16 says nobody should do work where "technical knowledge or experience is necessary to prevent danger" unless they have that knowledge, or are properly supervised (regulation 16).
HSR25 lists what that knowledge should cover (HSR25, paragraph 239):
- adequate knowledge of electricity
- adequate experience of the work being done
- an understanding of the system, and practical experience of that class of system
- an understanding of the hazards and the precautions
- "the ability to recognise at all times whether it is safe for work to continue"
That last one matters most at 4am. A mechanical fitter can be very good and still not know the drive. Even isolation counts. HSR25 says the person isolating needs "sufficient technical knowledge or experience to prevent danger during the isolation" (HSR25, paragraph 237).
HSE's FAQs say a finished electrical apprenticeship, plus some experience after it, is a good way to show competence for general electrical work. They add that work such as control system modification is "almost certainly likely to require additional training and experience" (HSE electrical FAQs).
So ask two questions about every shift. Have we got an electrician on? And have we got one who knows this kit?
What getting it wrong costs
Here's our view. Most sites are covered on days and thin on nights. The night fitter gets the electrical faults because there's nobody else. We think that's unfair on the fitter, and it puts you in a bad spot too.
At 4am you have three honest options. Let the fitter do what they're competent to do, and stop there. Wait for the day electrician. Or get someone in. Waiting has a price, and you can work it out in advance with the true cost of an hour of downtime. Getting it wrong has a price nobody wants to work out.
If your team is short on electrical skills, look at the mix. Fitters, electricians and controls engineers do different jobs, and nights show up the gaps.
What to do on Monday
- List who on each shift is competent for which electrical work: isolation, fault-finding, live testing, drives and PLCs. Be honest about the gaps.
- Find the maintenance and test records for your main boards and control panels. If you can't find them, you can't show due diligence.
- Check every electrician has a proper voltage tester and a proving unit.
- Decide now who the night shift calls for an electrical fault they can't safely handle.
* The list of regulations covered by the regulation 29 defence correct as of 8 October 2026. Check the Electricity at Work Regulations on legislation.gov.uk and HSR25 for the latest. HSR25 paragraph numbers refer to the third edition (2015).