Machine down at 2am: the phone call that decides the next six hours

It's 2am. The shrink wrapper's stopped on a servo fault. Your shift fitter has been in the panel for 40 minutes. They've reset it twice, swapped a fuse and checked the cables they can reach. It's still down.

The shift manager rings you at home. You're half awake. You have to decide who to call, and you have about two minutes to do it.

That call decides the next six hours. Get the right person on the way with the right facts, and the wrapper could be running by 4. Get it wrong and you'll still be on the phone when the day shift walks in.

Most of the time lost on a night breakdown goes on getting the right person to the machine. The repair itself is often the quick bit.

The call goes to whoever answers

Here's how it usually goes wrong. You ring the first number that comes to mind. That's often the mechanical fitter who lives closest, or the agency that picks up at 2am. Whoever is free gets sent.

They arrive at 3:15. They're a good fitter. But it's a servo drive, and they've never been online to that make of PLC. They don't have the laptop or the software. So at 4am you're ringing round again, and the second engineer gets there at 5:30.

That's three and a half hours lost on a job that might have taken one. Add the trailers that went out light and the shift you paid to stand around. If you've worked out what an hour of downtime really costs you, you'll know that number runs into thousands.

So the first question on the call is the trade, not the name. Is this mechanical, electrical or controls? A fitter, a sparky and a controls engineer do different jobs, and knowing which one you need saves the second callout.

Say what it is, then what it's doing

"The wrapper's down" tells an engineer nothing. They need enough to decide if they're the right person and what to bring. Have the shift manager read this out, or send it as a text with photos:

1. Machine, make and model, and the drive or PLC make if anyone knows it
2. The exact fault code or alarm text, with a photo of the HMI
3. What it was doing when it stopped
4. What's been tried, and what changed after each try
5. Whether it's isolated now, and who holds the locks
6. Site address, which gate, who meets them, and any induction or PPE rules

Item 2 matters most. A fault code lets a good engineer start thinking in the car. If the manual's gone missing, that code is often all anyone has to go on. Our guide to reading drive fault codes when the manual's gone covers what to do next.

Item 4 matters more than people think. "We reset it twice and it tripped again after a minute" tells the engineer a lot. "We tried a few things" tells them nothing, and they'll waste the first half hour repeating them.

Ask three questions back

Before you put the phone down, ask the engineer three things.

Have you worked on this kind of kit before? Not this exact machine, but this make of drive or PLC. An honest "no" at 2am is worth more than a confident "yes".

What will you bring? For a controls fault that means a laptop, the right software and the right cable. For a mechanical fault it might be a puller, a bearing heater or a set of shims.

When will you be here? Get a time, not "on my way". If it's more than an hour, ask if there's anyone closer who can start.

We'd also ask what they want done before they arrive. Most good engineers will say leave it alone, don't reset it again, and get the history off the HMI.

Your site, your risks

The engineer who turns up at 3am doesn't know your site. You still have to tell them about its risks. The law requires you to give the contractor's employer, or the self-employed engineer, "comprehensible information" on the risks on your site and how you control them (Management Regulations 1999, regulation 12).

At 3am that's a short brief at the gate. Where the isolators are. Who holds the locks. What else is running nearby. Where the first aider is on nights.

Then think about who's with them. HSE's lone working guidance lists work that needs at least one other person*, and that includes work "near exposed live electricity conductors" (HSE, lone working). If the engineer is fault-finding in a live panel, your shift fitter stays with them. Don't send them both off to different jobs to save time.

Competence works the same way. HSE's code of practice for PUWER says maintenance work "should only be done by people who are competent to do the work" (L22, paragraph 79). That cuts both ways. Your fitter shouldn't be left alone on a drive they don't know. And the person you call in should be competent on that kit. Being free at 2am doesn't count.

Our view: write the call list before you need it

Here's what we think. The 2am decision is too big to make half asleep.

Make a call list on a quiet afternoon. One line per type of fault, with who to ring first and second for each:

• mechanical: gearboxes, bearings, chains, conveyors
• electrical: motors, contactors, supplies, panels
• controls: PLCs, drives, servos, safety circuits
• specialist kit: the machine maker, the chiller firm, the compressor firm

Put it in the shift manager's office and on the panel door of your worst machines. Agree a trigger too. If the fault isn't found in 30 minutes, the shift rings for help. Our post on the 30-minute rule goes into that.

Then check the list works. Ring the numbers. Find out who answers at 2am and who goes to voicemail. A list of numbers that don't answer is worse than no list, because it gives you false comfort.

When they arrive

The call is half the job. The other half is having things ready so the engineer can start the minute they walk in. That means the manuals, drawings, PLC backup, spares and someone who knows the machine. We've covered that in what to have ready before the callout engineer arrives.

What to do on Monday

1. Write a call list by fault type, with a first and second number for each, and test every number.
2. Put the six-point brief on a card in the shift manager's office.
3. Tell your shift managers to ask for the trade first, and to ask what the engineer will bring.
4. Agree that nobody works in a live panel alone on nights, and write it down.

* HSE's list of work that needs at least one other person correct as of 26 August 2026. Check HSE's lone working guidance for the latest. Paragraph numbers refer to L22, fourth edition (2014, amended 2018).