User Manual

Banner Engineering Corp. • Minneapolis, MN U.S.A
www.bannerengineering.com • Tel: [phone]
4 P/N 50163 rev. E
Machine Safety Switches - SI-LS31R Series Limit Switch Style
Electrical Installation
Access to the Wiring Chamber
The wiring chamber is accessed via a hinged cover door which may be pried open using
a flat-blade screwdriver (see the dimension drawings on page 7). A conduit adapter is
supplied to convert the German M20 x 1.5 thread to ½" x 14 NPT. An accessory cable
gland which fits the M20 x 1.5 thread is available (see page 7).
Connection to a Machine
Two types of contacts are offered. The contacts between terminals 11–12 and 21–22
are the safety contacts, which are closed (i.e., they conduct) when the actuator is in
the home (0°) position. The contacts located between terminals 23–24 are considered
monitoring contacts, which should not be used for safety switching.
As illustrated in Figure 3, a normally-closed safety contact (i.e., a safety contact that is
closed when the actuator is in the home [0°] position) from each of two safety switches
per interlock guard must connect to a 2-channel safety module or safety interface in
order to achieve a control reliable interface to the master stop control elements of a
machine. Examples of appropriate safety modules include 2-channel emergency stop
(E-stop) safety modules and gate monitor safety modules.
Two functions of the safety module or safety interface are:
1. to provide a means of monitoring the contacts of both safety switches for
contact failure, and to prevent the machine from restarting if either switch fails;
and
2. to provide a reset routine after closing the guard and returning the safety switch
contacts to their closed position. This prevents the controlled machinery from
restarting by simply moving the safety switch actuators. This necessary reset
function is required by ANSI B11 and NFPA 79 machine safety standards.
Use only a positively driven, normally closed safety contact from each switch for
connection to the safety module. The normally open contact may be used for control
functions that are not safety-related. A typical use is to communicate with a process
controller. Refer to the installation instructions provided with the safety modules for more
information regarding the interface of the safety module to the machine stop control
elements.
Safety
Switch
#1
Safety
Switch
#2
Input
Channel
#1
Input
Channel
#2
2-channel Safety Module
(2-channel E-stop Module
2-channel Gate Monitor Module, etc.)
Single gate or guard
11 12 11 12
NOTE: Refer to the installation instructions provided with
the safety module for information regarding the
interface of the safety module to the machine stop
control elements.
Figure 3. Connect two redundant safety switches per interlock guard to an appropriate
2-channel input safety module.
CAUTION . . .
Electrical Installation
Two safety switches must be used
for each interlock guard to achieve
control reliability or Safety Category 4 (per ISO
13849-1, EN 954-1) of a machine stop circuit. Use
of only one safety switch per interlock guard is not
recommended.
In addition, normally-closed safety contacts
from each of the two safety switches should be
connected to the two separate inputs of a 2-channel
safety module or safety interface, as illustrated in
Figure 3. This is required to provide monitoring for
safety switch contact failure, and to provide the
necessary reset routine, as required by IEC 60204-
1 and NFPA 79 machine safety standards.
WARNING . . . Series Connection
of Safety Interlock Switches
Monitoring multiple guards with
a series connection of multiple
safety interlock switches is not a
Safety Category 4 Application (per ISO 13849-1,
EN 954-1).
A single failure may be masked or not detected at
all. When such a configuration is used, procedures
must be performed regularly to verify proper
operation of each switch.