After the summer break, a long bank holiday or a stoppage due to low demand, many plants make the same mistake: hit "start" and expect the robot to pick production back up as if nothing had happened. But a robot that has sat idle for weeks does not start the way one that runs every day does. A rushed restart after a long shutdown is one of the most common causes of avoidable breakdowns in the first hours back. This guide sums up, at plant level, how to bring the cell back safely and without surprises.
Why a long shutdown is not just any stop
When a robot runs every day, its own operation keeps several problems in check: heat drives off moisture, lubricant spreads through the gearboxes and wear is monitored continuously. During a long shutdown, by contrast, the equipment goes "cold" and risks appear that are worth knowing about:
- Moisture and condensation inside cabinets and motors, especially if the plant cools down and the climate control is off.
- Settled lubricant in gearboxes and gears, leaving poorly lubricated areas on the first start.
- Backup batteries discharging with the robot off, which can run out during the shutdown and cause the position counters to be lost.
- Depressurised pneumatics and possible leaks that previously went unnoticed.
- Dust, rodents or nearby building work that may have left their mark on cables and connectors.
None of these points is serious if you check it before powering up. The problem appears when they are ignored and the robot is asked to run at full output from minute one.
Before powering up: the cold inspection
With the robot still unpowered, spend a few minutes on an orderly visual check:
- Cabling and hoses: no chafing, bites, crushing or moisture at the connectors.
- Surroundings: no water, condensation or built-up dirt on the robot and the cabinet.
- Leaks: look for oil or grease stains under the axes and gearboxes; a new leak is a warning sign.
- Electrical cabinet: clean, dry and with the ventilation filters in good condition.
- Documentation to hand: the program backup and calibration data, in case you need them.
This job is far quicker when the shutdown was planned and the robot was left clean and documented before it was switched off. If that wasn't the case, take your time.
On power-up: check the alarms before moving anything
Power up the cabinet and let the system boot without commanding any movement. Before you touch anything:
- Check the warnings and alarms on the teach pendant. Dead batteries or lost position counters show up here.
- Check the state of the backup batteries. If the robot has lost its reference, don't force the start: you'll need to update the counters or recalibrate according to the manufacturer.
- Confirm the system date and time, and that there are no communication errors with peripherals.
The classic case of the batteries that hold the position is covered in more detail in SMB batteries in ABB robots: a cheap component that, ignored, ends up costing a full intervention.
First move: manual and at reduced speed
Never launch an automatic cycle as the first move after a long shutdown. In manual mode and at reduced speed:
- Jog each axis separately through its usual range.
- Listen: abnormal noises, vibration or "knocking" in a gearbox are a clear sign to inspect.
- Check that the robot holds the correct position and reference (mastering and calibration).
- Verify brakes, tooling and gripper before demanding loads.
If something doesn't sound or move the way it did before the shutdown, it's better to stop and check than to push on: forcing an axis with a damaged gearbox turns a minor repair into a major breakdown.
Before going back into production
- Run the program empty or at reduced speed for a couple of full cycles before loading a part.
- Check safety: emergency stops, fencing, scanners and limit switches.
- Review the process tooling (gripper, welding, dispensing) and its consumables.
- Watch temperatures and current draw in the first hours: a motor or gearbox running too hot needs attention.
When a professional check is worth it
A long shutdown is, in fact, the best time for a preventive check: you take advantage of the line being already stopped to lubricate, check for play, measure battery condition and bring the backup up to date without losing any extra production. If your fleet includes older or production-critical robots, building this restart into a preventive maintenance plan keeps the "back from holidays" moment from becoming a breakdown. At PAS Robotics we inspect and recommission robots from all the main brands —including ABB robot maintenance, KUKA and FANUC— so the first week after the shutdown is as productive as the last one before closing.
Frequently asked questions
Can I start the robot straight away after weeks idle?
It is not advisable to launch an automatic cycle as the first move. Do a cold inspection, power up while checking the alarms and jog the axes in manual at reduced speed before demanding production.
What if the robot has lost calibration during the shutdown?
If the backup batteries have run out, it may lose its position counters and error out on start-up. Don't force movement: update the counters or recalibrate following the manufacturer's procedure.
Is it a good time for preventive maintenance?
Yes. With the line already stopped, lubricating, checking for play, reviewing batteries and updating the backup costs no extra production and reduces the risk of breakdown on the way back.