BS ISO 21455:2020 Mobile elevating work platforms — Operator’s controls — Actuation, displacement, location and method of operation.
7.6.3 A function enable control that is integral with a control shall be protected against inadvertent activation by a single external force.
7.6.4 Controls requiring activation of a function enable control shall oniy allow activation if the control is in the neutral position prior to activating the function enable control.
7.6.5 Function enable controls shall deactivate after a period of no more than 10 s of inactivity
7.6.6 The requirements of 7.6.4 and 7.6.5 do not apply to controls that employ manually operated spool valves where the actuator is mechanically connected to the valve spool and provides visual or mechanical feedback of the spool position.
8 Layout of controls
8.1 General
Controls shall be laid out in accordance with this clause to reduce the possibility of error when an operator changes from one MEWP to another of similar type.
8.2 Control panel construction
8.2.1 The layout of controls is subject to the construction of the control panel. Alternative panel configurations, for example, multiple panels on different planes, can be used to provide an ergonomically acceptable layout.
8.2.2 The orientation of the controls relative to other controls shall remain consistent to this document.
8.3 Grouping of controls
8.3.1 Where controls are grouped together by function or feature, the controls shall be visually linked. No other controls shall be positioned in between the grouped controls.
8.3.2 Location on different planes is acceptable if, from the operator’s perspective, the controls are on the same visual axis (for example, a control button directly above the joystick).
8.3.3 Where a separate extending structure speed selector is provided, it shall be accessible by the alternate hand when using the applicable extending structure controls.
8.5.2 Where more than one control is used to move a single component of the extending structure, then the individual movement controls shall be grouped together and within this group ordered left to right or nearest to farthest: rotate, lift, telescope.
8.5.3 The platform level control shall be grouped separately from other extending structure controls.
8.5.4 The travel direction acknowledge control shall be grouped with the travel controls.
8.6 MEWPs with independent left-hand and right-hand travel controls
8.6.1 Where independent travel controls are provided, for example, tracked-type MEWPs, the travel controls shall be either grouped together or separated with the extending structure control positioned in the centre.
8.6.2 The left-hand control shall activate the left-hand drive and the right-hand control shall activate the right-hand drive.
9 Marking of controls
9.1 General
9.1.1 Markings of controls shall be clearly visible, durable and positioned sufficiently close to the control to avoid confusion over which marking applies to which control.
9.1.2 Markings shall not be placed on controls that allow the image or text to rotate to an upside-down position.BS ISO 21455 pdf download.