Banner MMD-TA-11B Muting Modules - Manual (Page 27)

P/N 116390 rev. C
25
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
WARNING . . . Multiple E-Stop
Switches
Whenever two or more Emergency Stop
switches are connected to the same Module:
• Contacts of the corresponding pole of each switch must
be connected together in series. Never connect the
contacts of multiple Emergency Stop switches in parallel
to one Module. Such a parallel connection connection
defeats the switch contact monitoring ability of the Module
and creates an unsafe condition which could result in serious
injury or death.
• Each switch must be individually actuated (engaged),
then re-armed and the Module reset. This allows the
controller to check each switch and its wiring to detect faults.
Failure to test each switch individually in this manner
could result in undetected faults and create an unsafe
condition which could result in serious injury or death.
This check must be performed during periodic checkouts
(see Section 6).
Category 3
A dual-channel hookup switching +24V dc is typically a category
3 application, because a single failure does not result in a loss
of safety. Loss of the switching action in one channel is detected
by the actuation of the E-stop button, the opening of the second
channel, and the monitoring function of the SSI inputs. However,
a short circuit between input channels or safety outputs may not
be detected. It should be noted that an accumulation of faults
may cause the loss of the safety function.
The principle of fault exclusion must be incorporated into the
design and installation to either eliminate, or reduce to an
acceptable (minimal) level of risk, the possibility of undetected
faults or catastrophic failures that could result in the loss of the
safety function.
Category 4
The self-monitoring SSI inputs can be interfaced to achieve a
category 4 application. The principle of fault exclusion must be
incorporated into the design and installation to either eliminate,
or reduce to an acceptable (minimal) level of risk, the possibility
of catastrophic failures or faults that could result in the loss of
the safety function.
Figure 3-17. SSI Category 3 interfacing: positive-opening
E-stop switch(es)
0V dc +24V dc
X6 (a)
X5 (b)
X8 (c)
X7 (d)
A2 A1
SSI
MMD-TA-..B
Figure 3-18. SSI Category 4 interfacing: positive-opening
E-stop switch(es)
0V dc +24V dc
X6 (a)
X5 (b)
X8 (c)
X7 (d)
A2 A1
SSI
MMD-TA-..B