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Installation of Hand Controls
Each actuating device typically requires a normally open and a normally closed
(e.g., Form C or SPDT) hard contacts, each capable of reliably conducting 20 mA at
12V dc. 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 acci-
dental or unintentional operation. Use shields, covers, rings, collars, dividers, or sim-
ilar protection to prevent accidental switch actuation and to discourage use of fore-
arms or elbows. European standard ISO13851 includes a detailed discussion of ap-
proaches to protection of hand controls.
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 ar-
rangement can allow shorter distances, per ISO13851 (EN574). This standard also
recommends that the hand controls be arranged on a horizontal (or nearly horizon-
tal) surface that is 1,100 mm/43.3" above the floor.
Ergonomic principles should be considered to avoid unnecessary fatigue in the in-
stallation of the hand controls. See ISO13851 (EN574) Two-Hand Control, ANSI
B11.TR1–Ergonomic Guidelines, and EN894–Safety of Machinery–Ergonomic Re-
quirements–Control Actuators for further information.
The figure to the right shows two examples for mounting Banner’s STB Touch But-
tons. When mounted on top of the control bar (Figure 6), the protective field covers
should be in place, as shown. For added protection, mount the devices sideways
under and behind a protective hood, rather than on top of the bar, leaving the field
covers off (Figure 7). 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
Figure 6. Install activation devices so that
they are protected to prevent defeat or inad-
vertent actuation (STB Touch Buttons shown)
Side Mount
Top Plate Shield
Figure 7. Mount devices sideways under a
protective hood for added protection (STB
Touch Buttons shown)
CAUTION: Install Hand Controls to Prevent Accidental Actuation
Total protection for the two-hand control system from “defeat” is not possible. However, the user is re-
quired by OSHA regulations to arrange and protect hand controls to minimize possibility of defeat
or accidental actuation.
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 responsibility of the user 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.
DUO-TOUCH
®
SG Two-Hand Control Modules
8
www.bannerengineering.com - tel: 763-544-3164
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