Risk class · Competent personnel only

This is not a repair procedure. Follow the exact manufacturer manual, site risk assessment and isolation process. If any energy source or safe state is uncertain, stop and escalate.

Before work starts

Remove the machine from service, identify every energy source and define who controls the isolation. HSE guidance says plant and equipment must be made safe before maintenance starts and that most maintenance should be performed with power off.

Isolation is more than the mains switch

Electrical power is only one hazard. Pneumatic pressure, hydraulics, gravity, springs, batteries, capacitors and suspended tooling can retain energy after a normal stop. HSE advises releasing stored energy and supporting components that could fall.

Prevent reconnection

Where accidental reconnection is possible, HSE advises locking off machinery and isolated valves. Use the site’s approved lockout process; never rely on software state, a warning light or an emergency stop as the only isolation.

Define the safe boundary

Keep unauthorised people outside the work area. Account for connected cells, conveyors, mobile bases, remote commands and automatic restart behaviour. Do not bypass guards, interlocks or safety controls to make diagnosis easier.

Return to service

Only a competent person should remove the isolation. Refit guards, clear tools and people, restore energy under the approved procedure, then complete the manufacturer-specified functional and safety checks.

When to stop

Stop around damaged lithium batteries, high voltage, unknown stored energy, unsupported axes, missing documentation, unexpected motion or any task outside your competence and authority.

Primary safety source

HSE — Maintenance of work equipment

Accessed 19 September 2026. This general briefing does not replace a robot manufacturer’s service manual, workplace risk assessment or competent professional advice.