Requirements for multiple-operator control – Banner DUO-TOUCH SG Two-Hand Control Safety Modules User Manual
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Each actuating device requires a normally open and a normally closed (e.g., Form C or SPDT) hard contact, each capable of reliably
conducting 25 mA at 24V dc (nominal). For complementary PNP operation, model STBVP.. touch buttons must be used to ensure proper
functionality.
Standards require that the actuating devices be mounted to protect them from accidental or unintentional operation. Use shields, covers,
rings, collars, dividers, or similar protection to prevent accidental switch actuation and to discourage use of forearms or elbows. European
standard ISO13851 includes a detailed discussion of approaches to protection of hand controls.
The installation of the hand controls must also consider:
• Failure modes that would result in a short circuit, a broken spring(s), mechanical seizure, etc. that would result in not detecting the
release of a hand control.
• Severe contamination or other environmental influences that may cause slow response when released or false ON condition of the
hand control(s), e.g., sticking of a mechanical linkage.
The hand controls must be arranged far enough apart so that the operator cannot operate both hand controls by the use of one arm.
Typically, this distance is not less than 550 mm/21.7” in a straight line, but using guards or alternate mounting arrangement can allow
shorter distances, per ISO13851 (EN574). This standard also recommends that the hand controls be arranged on a horizontal (or nearly
horizontal) surface that is 1,100 mm/43.3" above the floor for ergonomic purposes.
When installing the hand controls, consider ergonomic princi-
ples, in order to avoid unnecessary user fatigue. See
ISO13851 (EN574) Two-Hand Control, ANSI B11.TR1 – Er-
gonomic Guidelines, and EN894, Safety of Machinery – Er-
gonomic Requirements – Control Actuators for further infor-
mation.
The figure shows two examples for mounting Banner’s STB
Touch Buttons. When mounted on top of the control bar, the
protective field covers should be in place, as shown. For add-
ed protection, mount the devices sideways under and behind
a protective hood, rather than on top of the bar, leaving the
field covers off. This side mount reduces the possibility of the
operator easily positioning and leaving an object in the path
of the beam, intentionally bypassing the safeguard.
Field Covers
Top Mount
Side Mount
Top Plate Shield
Figure 3. Install activation devices so that they are protected to pre-
vent defeat or inadvertent actuation (Banner STB Touch Buttons
shown)
Requirements for Multiple-Operator Control
Standards have specified several conditions for situations where multiple operators work together to control one machine:
• Each operator must actuate his/her own pair of actuating devices, with all pairs of actuators active at one time, in order to initiate a
machine cycle; the machine may not be allowed to operate until this condition is true.
• The actuators all must be released between cycles.
• The actuation and de-actuation of all workstations requiring two-hand control must be supervisable and must provide indication.
• The clutch/brake control system must be designed so that the clutch cannot be actuated if all the operating workstations are by-
passed.
It is the user's responsibility to determine if this two-hand control system can be interfaced to the machine in a manner to
satisfy all existing requirements for multiple-operator control.
Two-Hand Control Safety Distance (Minimum Distance)
WARNING: Location of Touch Button Controls
Hand controls must be mounted a safe distance from moving machine parts, as determined by the
appropriate standard. It must not be possible for the operator or other non-qualified persons to relocate
them. Failure to establish and maintain the required safety distance could result in serious injury or
death.
AT-FM-10K Two-Hand Control Module
P/N 64137 Rev. G
www.bannerengineering.com - tel: 763-544-3164
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