Banner MMD-TA-11B Muting Modules - Manual (Page 15)

P/N 116390 rev. C
13
Banner Engineering Corp. • Minneapolis, U.S.A.
www.bannerengineering.com • Tel: 763.544.3164
MMD-TA-11B / MMD-TA-12B Muting Module
Instruction Manual
System Installation
3.1.1 Muting Application Design
Following are typical applications where muting is used. See
Appendix B for more detailed information.
• Entry/Exit Applications. The muting devices are placed to
allow the entry or exit of a pallet or cart of work materials to
enter or exit a workstation without tripping the safety light
screen, and without allowing the entrance of personnel into the
hazardous area.
• Home or Station Applications. The muting devices must be
placed to mute the safety light screen only when a hazard does
not exist or is in another area — so that personnel are not
exposed to any hazard.
• Robot Load/Unload Station Application. The “Station” muting
application uses independent safety light screen circuits,
each with its own muting circuit and sensors to protect work
locations. When a robot is active in Station A, for example,
Station B safety light screen is muted.
• Turret Table Application. A “Turret Table” application is
similar to the Robot Load/Unload Station muting application,
except that any movement of the table ends the mute.
• Power Press Applications. The muting devices are placed
so that the mute is initiated only during the non-hazardous,
opening portion of the cycle (typically the machine upstroke).
WARNING . . . Muting Limitations
Muting is allowed only during the non-
hazardous portion of the machine cycle (OSHA
1910.217(c)(3)(iii)(d), and ANSI B11.19.
WARNING . . . Guarding Multiple
Areas
DO NOT safeguard multiple areas, with mirrors
or multiple sensing fields, if personnel can enter the
hazardous area while the System is muted, and not be
detected by supplemental safeguarding that will issue a
stop command to the machine (see Section 3.1.4, Pass-
Through Hazards).
3.1.2 Use of Corner Mirrors with Optical Safety Systems
Mirrors are typically used with safety light screens and single-/
multiple-beam safety systems to guard multiple sides of
a hazardous area. If the safety light screen is muted, the
safeguarding function is suspended on all sides. It must not
be possible for an individual to enter the guarded area without
being detected and a stop command issued to the machine
control. This supplemental safeguarding is normally provided
by an additional device(s) that remains active while the Primary
Safeguard is muted and could be interfaced with the SSI
input. Therefore, mirrors are typically not allowed for muting
applications.
3.1.3 Multiple Presence-Sensing Safety Devices (PSSDs)
Muting multiple PSSDs or a PSSD with multiple sensing fields
is not recommended unless it is not possible for an individual
to enter the guarded area without being detected and a stop
command issued to the machine control. As with the use of
corner mirrors (see above), if multiple sensing fields are muted
the possibility exists that personnel could move through a muted
area or access point to enter the safeguarded area without being
detected.
For example, in an entry/exit application where a pallet initiates
the mute cycle by entering a cell, if both the entry and the exit
PSSDs are muted, it may be possible for an individual to access
the guarded area through the “exit” of the cell. An appropriate
solution would be to mute the entry and the exit with separate
safeguarding devices.