Datasheet
SI-LS31 Series Safety Limit (Position) Switches for Interlocking and Position Monitoring
• Limit-switch style (EN 50047 and Type 1 per ISO 14119) where actuating elements are integrated with the
enclosure
• Positive opening safety contacts (IEC 60947-5-1) (not dependent on springs)
• Can be used for safety or non-safety interlocking and position monitoring
• Choice of actuating systems: plunger, roller, spindle-mount lever, and two lever styles
• Actuator head rotatable in 90° increments
• IP65 glass-reinforced thermoplastic switch housing; addition of screw to wiring chamber door to minimize defeat
• Insulated device (IEC 60947-5-1) on all models with plastic housings
• When properly interfaced or used with an appropriate controller, two switches monitoring an individual guard can
achieve safety category 4, per ISO 13849-1 (EN 954-1)
• Typical applications include monitoring sliding (laterally) gates and guards on machines and in safety fencing
systems
Models
Model Actuating System (See Figure) Contact Configuration Switching Diagram
SI-LS31PBD
Plunger
One N.C. and one N.O.
See Figure 1 on page 5SI-LS31PBE Two N.C.
SI-LS31PBF Two N.C. and one N.O.
SI-LS31RC10D
Roller
One N.C. and one N.O.
See Figure 2 on page 6SI-LS31RC10E Two N.C.
SI-LS31RC10F Two N.C. and one N.O.
SI-LS31LA18D
Spindle-mount lever (18 mm roller)
One N.C. and one N.O.
See Figure 3 on page 7
SI-LS31LA18E Two N.C.
SI-LS31LA18F Two N.C. and one N.O.
SI-LS31LE11D
Lever (11 mm roller)
One N.C. and one N.O.
See Figure 4 on page 8SI-LS31LE11E Two N.C.
SI-LS31LE11F Two N.C. and one N.O.
SI-LS31L22D
Lever (22 mm roller)
One N.C. and one N.O.
See Figure 5 on page 9SI-LS31L22E Two N.C.
SI-LS31L22F Two N.C. and one N.O.
Safety Limit Switches
Original Document
182190 Rev. A 6 March 2015
182190
Important... Read this before proceeding!
The user is responsible for satisfying all local, state, and national laws, rules, codes, and regulations relating to
the use of this product and its application. Banner Engineering Corp. has made every effort to provide complete
application, installation, operation, and maintenance instructions. Please contact a Banner Applications Engineer with any
questions regarding this product.
The user is responsible for making sure that all machine operators, maintenance personnel, electricians, and
supervisors are thoroughly familiar with and understand all instructions regarding the installation, maintenance, and use of
this product, and with the machinery it controls. The user and any personnel involved with the installation and use of this
product must be thoroughly familiar with all applicable standards, some of which are listed within the specifications.
Banner Engineering Corp. makes no claim regarding a specific recommendation of any organization, the accuracy or
effectiveness of any information provided, or the appropriateness of the provided information for a specific application.
Overview
Use the SI-LS31xxx series safety limit switches to monitor the position of a guard to detect the movement, opening, or
removal. A "guard" can be a gate, door, cover, panel, barrier or other physical means that separates an individual from a
hazard. Safety switches will issue a signal to the machine control system to prevent or stop (halt) hazardous situations
when the guard is not in the proper position. These Safety switches are designed for non-locking guarding applications,
unless another means of locking is provided.
The SI-LS31xxx series safety limit switches are considered a Type 1 interlocking device per ISO 14119 that are
mechanically actuated by an uncoded rotary or linear actuator (cam or "dog") typically mounted on or part of the guard. A
variety of actuating systems are available: plunger (dome), roller plunger, spindle-mount lever roller, and lever.
Installation Requirements
The following general requirements and considerations apply to the installation of interlocked gates and guards for the
purpose of safeguarding. In addition, the user must refer to the relevant regulations and comply with all necessary
requirements. See ANSI B11.19, or ISO 14119 and ISO 14120, or the appropriate standard.
Hazards guarded by the interlocked guard must be prevented from operating until the guard is closed; a stop command
must be issued to the guarded machine if the guard opens while the hazard is present. Closing the guard must not, by
itself, initiate hazardous motion; a separate procedure must be required to initiate the motion.
Locate the guard an adequate distance from the danger zone (so the hazard has time to stop before the guard is opened
sufficiently to provide access to the hazard). Guard locking or supplemental safeguarding must be used if the overall
stopping time of the machine or the time to remove the hazard is greater than the time to access the guarded area. The
guard must open either laterally or away from the hazard, not into the safeguarded area. The guard also should not be
able to close by itself and activate the interlocking circuitry. The installation must prevent personnel from reaching over,
under, around or through the guard to access the hazard. Any openings due to positioning, movement, or misalignment in
the guard must not allow access to the hazard—see ANSI B11.19, ISO 13855, ISO 13857, or the appropriate standard.
The guard must be strong enough and designed to protect personnel and contain hazards within the guarded area that can
be ejected, dropped, or emitted by the machine. Mount them securely so that their physical position cannot shift, using
reliable fasteners that require a tool to remove. Mounting slots in the housing, if provided, are for initial adjustment only;
final mounting holes (round) must be used for permanent location. The switches, actuating systems, and actuators must
not be used as a mechanical or end-of-travel stop.
The normally closed safety contacts are of a "positive-opening" design. Positive-opening operation causes the contacts to
be forced open, without the use of springs, when the actuator is disengaged or moved from its home position. In addition,
the switch(es) must be mounted in a "positive mode", to move/disengage the actuating system and actuator from its
home position and open the normally closed contact, when the guard opens.
See Mechanical Installation on page 3 Electrical Installation on page 10, Switching Diagrams on page 5, and
Specifications on page 13 for additional information.
Design and install the safety switches and actuators so that they cannot be easily defeated. Measures to minimize defeat
(bypassing) of interlocking safety switches include:
• Minimizing motivation for defeating interlocking by providing training, supervision, and efficient means for machine
setup/adjustment, operation and maintenance
• Limiting accessibility to the interlocking device, such as mounting out of reach, mounting behind a physical
obstruction, mounting in a concealed position
• Preventing actuation by readily available objects or tools
• Preventing the switch or the actuator from being disassembled or repositioned that compromises the safety
function. (for example, welding, one-way screws, riveting)
• Control system monitoring of cyclic switch functioning and redundant means of interlocking
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• Using hardware that requires a tool to remove that is not readily available.
WARNING: Interlocked Guards
The user must refer to the relevant regulations and comply with all necessary requirements. See ANSI
B11.19, or ISO 14119 and ISO 14120, or the appropriate standard. At a minimum, the interlocked
guard must prevent hazards when not fully closed and must also prevent access to the hazards through
any opening in the guard. The safety switches and actuators must be designed and installed so that
they cannot be easily defeated, and are not used as a mechanical or end-of-travel stop. At least one
switch must be mounted in a positive mode and open the normally closed contact when the guard
opens. Failure to follow these guidelines may result in serious bodily injury or death.
CAUTION: End-of-Travel Stop
Do not use the safety switch as a mechanical or end-of-travel stop.
The movement or rotation of the guard must be limited such that damage to the safety switch or the
actuator cannot occur. Catastrophic damage can cause the safety switch to fail in an unsafe
manner (that is, loss of the switching action).
WARNING: Safety Distances and Safe Openings
It must not be possible for personnel to reach any hazard through an opened guard or by reaching
over, under, around, or through any opening in the guard before the hazardous situation has ceased.
See ANSI B11.19 or ISO 14119, ISO 14120 and ISO 13857 for information on determining safety
distances and safe opening sizes for your guarding device.
Pass-through hazards and Perimeter Guarding
A pass-through hazard is associated with applications where personnel may pass through a safeguard (which issues a stop
command to remove the hazard), and then continues into the guarded area, such as in perimeter guarding. Subsequently,
their presence is no longer detected, and the related danger becomes the unexpected start or restart of the machine while
personnel are within the guarded area.
Eliminate or reduce pass-through hazards whenever possible—see ANSI B11.19 and ANSI B11.20 or ISO 11161. One
method to mitigate the risk is to ensure that once tripped, either the safeguarding device, the safety related part of the
control system, or the guarded machine's MSCs/MPCEs will latch in an OFF condition. The latch must require a deliberate
manual action to reset that is separate from the normal means of machine cycle initiation.
This method relies upon the location of the reset switch as well as safe work practices and procedures to prevent an
unexpected start or restart of the guarded machine. All reset switches must be:
• Outside the guarded area
• Located to allow the switch operator a full, unobstructed view of the entire guarded area while the reset is
performed
• Out of reach from within the guarded area
• Protected against unauthorized or inadvertent operation (such as through the use of rings or guards)
If any areas within the guarded area are not visible from the reset switch, additional safeguarding must be provided.
WARNING: Pass-Through Hazards and Perimeter Guarding
Lockout/Tagout procedures per ANSI Z244.1 may be required, or additional safeguarding, as described
by ANSI B11.19 safety requirements or other appropriate standards, must be used if a passthrough
hazard cannot be eliminated or reduced to an acceptable level of risk. Failure to observe this warning
may result in serious bodily injury or death.
Mechanical Installation
Important: Install a safety switch in a manner which discourages tampering or defeat. Mount switches
to prevent bypassing of the switching function at the terminal chamber or Quick Disconnect (QD). A
switch and its actuator must never be used as a mechanical stop. Overtravel may cause damage to
switch.
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All mounting hardware is supplied by the user. Fasteners must be of sufficient strength to guard against breakage. Use of
permanent fasteners or locking hardware is recommended to prevent the loosening or displacement of the actuator and
the switch body. The mounting holes in the switch body accept M5 screws.
Safety limit switches and their actuators (cams, dogs, etc.) must be mounted such that the position cannot be changed
after installation/adjustment. Mount the switch securely on a solid, stationary surface that can accommodate the forces of
actuator movement. The loosening of mounting hardware must be prevented (for example, lock washers, thread-locking
compound). The use of slots should only be used for initial positioning. Pins, dowels, and splines can be used to prevent
movement of the switch and the actuator (cam).
The safety limit switch must be installed to prevent false or unintended actuation and intentional defeat.
Safety limit switches should be located in such a manner that allows access for functional checks, maintenance, and
service or replacement. The installation should provide suitable clearances, be readily accessible, and allow access to the
actuator system (for example, roller lever) and switch body covers.
Safety limit switches should not be used in environments that subject the switch, the actuating system, or the actuator
(cam) to extreme temperatures and vibration/shock or where excessive moisture (water, oils, coolants, etc.) or machining
chips/swarf and dust can be reasonably expected.
Actuating System and Actuator (Cam) Considerations
Actuating systems and actuators must be installed per the dimensioning diagram and the movement of the actuating
system must remain within the specified operating range. The slope of the actuator (cam) must not be greater than
specified and the construction material must be of sufficient hardness to ensure proper operation of the life time of the
machine.
The actuating system must travel the required distance to operate the positive opening normally closed contacts, but not
exceed the maximum travel listed on the switching diagrams. The installation must account for any mechanical
inaccuracies, tolerance issues, wear, misalignment, etc. in the actuator (cam) and the actuating system of the switch by
allowing sufficient post-travel after the positive opening point.
When used in a safety application, the actuating system must be operated by direct mechanical action (positive mode) of
the actuator (cam) and the guard that engage the direct positive opening of the normally closed safety contacts. Non-
direct mechanical action (negative mode) that relies on spring force should only be used in conjunction with a Type 1 or
Type 2 (key/tongue actuated) interlocking switch mounted in the direct action positive mode as a redundant,
complementary monitoring channel (see Figure 7 on page 11).
Actuators (cams) must be designed and installed to:
• Ensure that the limit switch contacts are operated long enough to ensure that a proper signal is transmitted to
operate connected devices or safety modules and controllers
• Ensure the actuator is not operated beyond its overtravel limits
• Ensure that the actuator does not receive severe impact from fast moving cams
• Ensure the actuator does not snap back into to position by an abrupt release
• Not use additional or modified actuators
Do not use the switch, actuating system, or the actuator (cam) as a mechanical end of travel stop. If you change the
position of the actuator, ensure the correct reassembly for proper operation.
Safety Limit Switches
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Switching Diagrams
Safety
Safety
Safety
Safety
Safety
Non-Safety
Non-Safety
Contacts: Open Closed Transition
Switching Diagram tolerances:
Operating point ± 0,25mm;
Operating force ± 10%
Contact Configuration (Guard Closed State)
SI-LS31PBD SI-LS31PBE SI-LS31PBF
CAM
Preferred direction
of actuation
α α
β β
Guard closed (home position) is at 0
mm when mounted in a positive mode.
Not to scale.
Maximum allowable travel varies by
model and is listed at bottom of
switching diagram (minus operating
tolerance).
Installation must ensure sufficient travel
for positive opening of safety contacts
and account for any mechanical
tolerances.
0.1 m/s
0.5 m/s
1 m/s
2 m/s
α
30°
5°
-
-
β
20°
20°
10°
5°
Max. Approach speed vs. Max. Approach angle
Preferable direction of actuation is parallel to the plunger axis (α°).
Exceeding specified approach angle or speed can reduce life
expectancy.
Figure 1. SI-LS31Px Switching Diagrams
NOTE: This symbol for a positive-opening safety contact (IEC 60947-5-1) is used in the switching
diagram to identify the point in actuator travel where the normally-closed safety contact is fully open.
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β
Direction of
Actuation
CAM
Guard closed (home position) is at 0 mm when mounted in a positive
mode. Not to scale.
Maximum allowable travel varies by model and is listed at bottom of
switching diagram (minus operating tolerance).
Installation must ensure sufficient travel for positive opening of safety
contacts and account for any mechanical tolerances.
Actuating system can be removed and reposition/rotated by 90°.
Ensure all screws are properly re-installed.
0.1 m/s
0.5 m/s
1 m/s
2 m/s
5 m/s
β
30°
30°
20°
10°
5°
Max. Approach speed vs. Max. Approach angle
Direction of actuation is perpendicular to the actuating system axis.
Exceeding specified approach angle or speed can reduce life
expectancy.
Contact Configuration (Guard Closed State)
SI-LS31RC10D SI-LS31RC10E SI-LS31RC10F
Contacts: Open Closed Transition
Switching Diagram tolerances:
Operating point ± 0.25 mm
Operating force ± 10%
Safety
Safety
Safety
Safety
Safety
Non-Safety
Non-Safety
Ø10
23.5
7.5
21.5
M5(X2)
β
β
Figure 2. SI-LS31RC10x Switching Diagrams
NOTE: This symbol for a positive-opening safety contact (IEC 60947-5-1) is used in the switching
diagram to identify the point in actuator travel where the normally-closed safety contact is fully open.
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8Ncm
11 – 12
0°
35°
80°
20°
21 – 22
Contact Configuration (Guard Closed State)
SI-LS31LA18D SI-LS31LA18E SI-LS31LA18F
Contacts: Open Closed Transition
Switching Diagram tolerances:
Operating point ± 3.5 °
Operating torque ± 10%
Safety
Safety
Safety
Safety
Safety
Non-Safety
Non-Safety
Guard closed (home position) is at 0° when mounted in a positive
mode. Not to scale.
Maximum allowable travel varies by model and is listed at bottom of
switching diagram (minus operating tolerance). Switching Angles (θ)
are measured with actuating system in vertical position (as drawn) and
are applicable both left and right movement.
Installation must ensure sufficient travel for positive opening of safety
contacts and account for any mechanical tolerances.
Actuating system can be removed and reposition/rotated by 90°
increments. Ensure all screws are properly re-installed.
β
Direction of
Actuation
CAM
0.1 m/s
0.5 m/s
1 m/s
2 m/s
β
45°
45°
45°
40°
Direction of actuation is perpendicular to the actuating system axis.
Exceeding specified approach angle or speed can reduce life
expectancy.
Max. Approach speed vs. Max. Approach angle
21.5
Ø18
53.5
7.5
θ
M5(X2)
β
β
Figure 3. SI-LS31LA18x Switching Diagrams
NOTE: This symbol for a positive-opening safety contact (IEC 60947-5-1) is used in the switching
diagram to identify the point in actuator travel where the normally-closed safety contact is fully open.
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Contacts: Open Closed Transition
Switching Diagram tolerances:
Operating point ± 0.25 mm
Operating force ± 10%
Guard closed (home position) is at 0 mm when mounted
in a positive mode. Note to scale.
Maximum allowable travel varies by model and is listed at
bottom of switching diagram (minus operating tolerance).
Installation must ensure sufficient travel for positive
opening of safety contacts and account for any mechani-
cal tolerances.
The actuator can only approach from the hinge side.
Actuator can be removed and reposition/rotated by 90°
increments. Ensure all screws are properly re-installed.
Max. Approach speed vs. Max. Approach angle
Direction of actuation is perpendicular to the actuating system axis
and only from the hinge side of the actuator. Exceeding specified
approach angle or speed can reduce life expectancy.
0.1 m/s
0.5 m/s
1 m/s
2 m/s
5 m/s
β
40°
40°
30°
20°
10°
β
CAM
Direction of
Actuation
Ø11
35.5
7.5
21.5
M5(X2)
0mm
1.5
3
4
8
11 - 12
23 - 24
10N
0mm
0.8
2.1
5
11 - 12
21 - 22
3N
7N
0mm
0.8
2
2.3
5
11 - 12
21 - 22
33 - 34
2N
6N
β
Contact Configuration (Guard Closed State)
SI-LS31LE11D SI-LS31LE11E SI-LS31LE11F
Safety
Safety
Safety
Safety
Safety
Non-Safety
Non-Safety
Figure 4. SI-LS31LE11x Switching Diagrams
NOTE: This symbol for a positive-opening safety contact (IEC 60947-5-1) is used in the switching
diagram to identify the point in actuator travel where the normally-closed safety contact is fully open.
Safety Limit Switches
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Contact Configuration (Guard Closed State)
SI-LS31L22D SI-LS31L22E SI-LS31L22F
Contacts: Open Closed Transition
Switching Diagram tolerances:
Operating point ± 0.25 mm
Operating force ± 10%
Guard closed (home position) is at 0 mm when mounted
in a positive mode. Not to scale.
Maximum allowable travel varies by model and is listed at
bottom of switching diagram (minus operating tolerance).
Installation must ensure sufficient travel for positive
opening of safety contacts and account for any mechani-
cal tolerances.
The actuator can only approach from the hinge side.
Actuator can be removed and reposition/rotated by 90°
increments. Ensure all screws are properly re-installed.
Max. Approach speed vs. Max. Approach angle
Direction of actuation is perpendicular to the actuating system axis
and only from the hinge side of the actuator. Exceeding specified
approach angle or speed can reduce life expectancy.
0.1 m/s
0.5 m/s
1 m/s
2 m/s
β
40°
40°
30°
20°
β
CAM
Direction of
Actuation
0mm
1.3
3.5
8
11 - 12
21 - 22
1.5N
6.5N
0mm
2
2.8
6.5
12
11 - 12
23 - 24
1N
6.5N
0mm
0.8
2
2.3
5
11 - 12
21 - 22
33 - 34
2N
6N
Ø22
51
7.5
21.5
M5(X2)
Actuating system positioned at
9 mm (default) from centerline.
Safety
Non-Safety
Safety
Safety
Safety
Safety
Non-Safety
β
Figure 5. SI-LS31L22x Switching Diagrams
NOTE: This symbol for a positive-opening safety contact (IEC 60947-5-1) is used in the switching
diagram to identify the point in actuator travel where the normally-closed safety contact is fully open.
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Electrical Installation
WARNING: Shock Hazard and Hazardous Energy
Always disconnect power from the safety system (for example, device, module, interfacing,
etc.) and the machine being controlled before making any connections or replacing any
component.
Electrical installation and wiring must be made by Qualified Personnel1 and must comply with the
relevant electrical standards and wiring codes, such as the NEC (National Electrical Code), ANSI
NFPA79, or IEC 60204-1, and all applicable local standards and codes.
Lockout/tagout procedures may be required. Refer to OSHA 29CFR1910.147, ANSI Z244-1, ISO
14118, or the appropriate standard for controlling hazardous energy.
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. A single
M20 × 1.5 threaded port allows wiring to be routed via conduit or a cable gland. A conduit adapter is supplied to convert
the M20 × 1.5 thread to ½" × 14 NPT. An accessory cable gland (SI-QS-CGM20) which fits the M20 × 1.5 thread is
available, see Accessories on page 15).
Figure 6. Accessing the Wiring Chamber
Connection to a Machine
Perform a risk assessment to determine the appropriate level of safety circuit performance (integrity) and the means of
interfacing the switch(es) with the machine control circuit. While Banner Engineering always recommends the highest level
of safety in any application, the user is responsible to safely install, operate, and maintain each safety system and comply
with all relevant laws and regulations.
To ensure the highest level of reliability (Control Reliable or Category 4, for example), wire the contacts from each of two
individual safety switches per interlock guard in a dual channel hookup. At a minimum, one of these two contacts must be
the positively-driven normally closed safety contact (S1 in Figure 7 on page 11).
Depending on the application, the redundant switch contact will be a positively-driven normally closed safety contact (if
mounted in a positive mode), or a normally open monitoring (non-safety) contact held closed by the cam on the guard (if
mounted in a negative mode). In either scenario, the dual channel hookup is monitored by a safety module (for example,
ES-FA-9AA), safety controller (for example, SC22-3 or SC/XS26-2), or the safety related part of the machine control that
complies with the required level of safety performance.
1A person who, by possession of a recognized degree or certificate of professional training, or who, by extensive knowledge, training and experience, has
successfully demonstrated the ability to solve problems relating to the subject matter and work.
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Normally closed safety contacts (11/12 or 21/22) are monitored by the safety module when both switches are mounted in
the positive mode (that is, opening the guard actuates S1 and S2; circuit on left).
One normally closed safety contact (11/12 or 21/22) from the switch mounted in the positive mode (S1) and one normally
open contact (23/24 or 33/34) from the switch mounted in the negative mode (S2) are monitored by the safety module
(that is, opening the guard actuates S1 and releases S2; circuit on right).
Refer to the installation instructions provided with the safety module or safety controller for information regarding the
interface to the machine stop control elements.
Figure 7. Connect two redundant safety switches per interlock guard to an appropriate 2-channel input safety module
Two functions of the safety module or safety controller 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.
2. To provide a reset routine after closing the guard and returning the safety contacts to their closed position. This
prevents the controlled machinery from restarting by simply closing the guard (reinserting the key/actuator, for
example). This necessary reset function is required by ANSI B11.0, ANSI/NFPA 79, and IEC 60204-1 machine
safety standards.
WARNING: Safety Circuit Integrity
A risk assessment must be performed to determine the appropriate safety circuit integrity
level or category to ensure the expected risk reduction is achieved and all relevant regulations and
standards are met (see ANSI B11.0 and ANSI B11.19, ISO 12100 and ISO13849-1 or the appropriate
standards).
Important:
The design, installation, and the means of interfacing of the safety switches greatly impact the level of
safety circuit integrity. It is recommended that two individual safety switches be used to monitor each
guard and that at least one normally-closed safety contact and an additional contact, depending on the
application, must be connected in a dual channel method to a safety module or safety controller to
achieve control reliability (ANSI B11.19) or Category 3 or 4 (ISO 13849-1, EN 954-1). This is required
to provide monitoring for safety switch failure, and to provide the necessary reset routine, as required
by NFPA 79 and IEC 60204-1. Use of only one safety switch per interlock guard is not
recommended in situations that can result in serious injury or death.
Monitoring Series-Connected Safety Switches
When monitoring the position of several guards with a single safety module or controller, the contacts of the corresponding
pole of each switch must be connected together in series. Never connect the contacts of multiple switches in parallel. Such
a parallel connection can defeat the switch contact monitoring ability of the module and could create an unsafe condition.
When multiple safety switches are series connected, the failure of one switch in the system may be masked or not be
detected at all. The following two scenarios assume two positive-opening safety switches on each guard, both connected in
series to switches of a second guard (dual channel hookup) and monitored by a safety module or safety controller:
•Masking of a failure—If a guard is opened but one switch fails to open, the redundant safety switch on that guard
opens and a protective (safety) stop occurs. If the faulty guard is then closed, the module/controller will not reset
because one channel did not open, thus complying with the required fault detection. However, if a second "good"
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guard is cycled (opening and then closing both of the channels), the failure appears to be corrected (input
requirements satisfied) and the module/controller allows a reset. This system is no longer redundant and, if the
second switch fails, may result in an unsafe condition (the accumulation of faults resulting in loss of the safety
function).
•Non-detection of a failure—If a functional guard is opened, both channels open and the module/controller
initiates a protective (safety) stop. If a guard with a faulty safety switch is then opened and closed before the good
guard is re-closed, the faulty switch is not detected. The system is no longer redundant and may result in a loss of
safety if the redundant switch fails to open when needed.
The system in either scenario does not inherently comply with the safety standard requirements of detecting a single fault
and preventing the next cycle (not a Category 4 application per ISO 13849-1). In multiple-guard systems using series-
connected safety switches, it is important to periodically check the functional integrity of each interlocked guard
individually. Open and close each guard separately while verifying that the machine properly responds. Operators,
maintenance personnel, and others associated with the operation of the machine must be trained to recognize
failures and be instructed to correct them immediately.
WARNING: Series Connection of Safety Switches
Monitoring multiple guards with a series connection of safety interlock switches may result in a failure
being masked or not detected at all. When such a configuration is used, periodic checks must be
performed regularly to verify proper operation. All failures must be immediately corrected (for example,
immediately replacing a failed switch), or the loss of the safety stop signal or an inappropriate reset
may lead to serious injury or death.
Maintenance
Checkout
At switch installation or replacement and at machine set up, a Designated Person2 must test each switch for proper
machine shutdown response and check the switch(es) and installation for proper operation, physical damage, mounting
(looseness), and excessive environmental contamination. This must also take place on a periodic schedule determined by
the user, based on the severity of the operating environment and the frequency of switch actuations. Adjust, repair, or
replace components as needed. If inspection reveals contamination on the switch, thoroughly clean the switch and
eliminate the cause of the contamination. Replace the switch and/or appropriate components when any parts or
assemblies are damaged, broken, deformed, or badly worn; or if the electrical/mechanical specifications (for the
environment and operating conditions) have been exceeded. Always test the control system for proper functioning
under machine control conditions after performing maintenance, replacing the switch, or replacing any component of the
switch.
Additional items that should be included in the checkout and/or regularly scheduled maintenance of a safety limit switch,
actuating system, and actuator (cam) are:
• Verify proper positioning of switch, actuating system (for example, roller lever), and cam or dog
• Verify correct switching function (actuator system has free movement and within switching distance specifications)
• Correct any misalignment or overrun between the actuator and the actuator system
Repairs
Do not attempt any repairs to the safety interlocking switch. It contains no field-replaceable components.
Return it to Banner Engineering for warranty repair or replacement.
Contact Banner Factory Application Engineering. They will attempt to troubleshoot the system from your description of the
problem. If they conclude that a component is defective, they will issue a return merchandise authorization (RMA) number
for your paperwork, and give you the proper shipping address.
Important: Pack the safety switches carefully. Damage that occurs in return shipping is not
covered by warranty.
2A Designated Person is identified in writing by the employer as being appropriately trained to perform a specified checkout procedure.
Safety Limit Switches
12 www.bannerengineering.com - Tel: +1-763-544-3164 P/N 182190 Rev. A
Specifications
UL/CSA Contact Rating
SI-LS31xxD: A300 (same polarity): 3 A at 240 V ac, 6 A at 120 V ac
SI-LS31xxE: B300 (same polarity): 1.5 A at 240 V ac, 3 A at 120 V
ac; Q300: 0.27 A at 240 V dc, 0.55 A at 120 V dc
SI-LS31xxF: B300 (same polarity): 1.5 A at 240 V ac, 3 A at 120 V ac
European Rating, Utilization categories (IEC/EN 90497-5-1):
SI-LS31xxD: Ui = 250 V ac, Ith = 10 A, Uimp = 4 KV, AC15 Ue/Ie 240
V/3 A, 120 V/6 A
SI-LS31xxE: Ui = 250 V ac, Ith = 5 A, Uimp = 2.5 KV, AC15 Ue/Ie 240
V/1.5 A, 120 V/3 A
SI-LS31xxF: Ui = 250 V ac, Ith = 5 A, Uimp = 2.5 KV, AC15 Ue/Ie 240
V/1.5 A, 120 V/3 A
Electrical Protection Class
II, totally insulation
Contact Function
Slow-action make and break contacts. See Switching Diagrams.
Switching Frequency
≤ 100 per minute
Contact Material
Silver-nickel alloy
Mechanical Life
SI-LS31xxD: 10 × 106 operations
SI-LS31xxE: 1 × 106 operations
SI-LS31xxF: 1 × 106 operations
B10d
SI-LS31xxD: 20 × 106 cycles (N.C. contact)
SI-LS31xxE: 2 × 106 cycles (N.C. contact)
SI-LS31xxF: 2 × 106 cycles (N.C. contact)
Short Circuit Protection
Recommended external fusing or overload protection.
SI-LS31xxD: 10 amp Slow Blow
SI-LS31xxE: 6 amp Slow Blow
SI-LS31xxF: 6 amp Slow Blow
Wire Connections
Screw terminals with pressure plates accept the following wire sizes.
Ferrules are recommended for stranded wire.
Stranded and solid: 0.5 mm² (20 AWG) to 1.5 mm² (16 AWG) for
one wire
Stranded: 0.5 mm² (20 AWG) to 1.0 mm² (18 AWG) for two wires
Maximum Tightening Torque
SI-LS31xxD: 1.3 N·m
SI-LS31xxE: 0.6 N·m
SI-LS31xxF: 0.6 N·m
Cable Entry
One M20 × 1.5 threaded entrance. Adapter supplied to convert M20 x
1.5 to 1/2" - 14 NPT threaded
Construction
Enclosure: Thermoplastic, glass fiber reinforced (UL 94-V0)
Actuator:
SI-LS31PBx (Plunger): Thermoplastic
SI-LS31RC10x (10 mm Roller): Thermoplastic
SI-LS31LA18x (Spindle-mount Lever with 18 mm roller): Steel,
Thermoplastic
SI-LS31LE11x (Lever with 11 mm roller): Thermoplastic
SI-LS31L22x (Lever 22 mm roller): Thermoplastic
Environmental Rating
IEC IP65 according to IEC/EN 60529
The degree of protection (IP code) specified applies solely to a properly
closed cover and the use of an equivalent cable gland with adequate
cable. A M2.2×12x5 mm screw can be installed in the cover to provide
additional security.
Operating Conditions
–30 °C to +80 °C (–34 °F to +176 °F)
Mounting
2 × M5 screws DIN 912 (on a flat and stiff surface)
Tightening torque: Mdmax. = 1.5 N·m
Weight (approximate)
SI-LS31PBx: 0.06 kg
SI-LS31RC10x: 0.07 kg
SI-LS31LA18x: 0.1 kg
SI-LS31LE11x:0.07 kg
SI-LS31L22x: 0.07 kg
Applicable Standards
VDE 0660 T100, DIN EN 60947-1, IEC 60947-1
VDE 0660 T200, DIN EN 60947-5-1, IEC 60947-5-1
DIN EN ISO 13849-1
Approvals
SI-LS31xxD: CCSAUS A300 (same polarity)
SI-LS31xxE: CCSAUS B300 (same polarity), Q300
SI-LS31xxF: CCSAUS B300 (same polarity)
Certifications
Safety Limit Switches
P/N 182190 Rev. A www.bannerengineering.com - Tel: +1-763-544-3164 13
Dimensions
All measurements are listed in millimeters (inches), unless noted otherwise.
Adjustable in ≈ 1 mm
increments ± 3 mm
SI-LS31L22x
SI-LS31LE11xSI-LS31RC10x
SI-LS31PBx SI-LS31LA18x
Safety Limit Switches
14 www.bannerengineering.com - Tel: +1-763-544-3164 P/N 182190 Rev. A
Accessories
Cable Glands
Model Size For Cable
Diameter Dimensions Used With
SI-QS-CGM20 M20 × 1.5 Plastic 5.0 to 12.0 mm
(0.20 to 0.47 inches)
M20 x 1.5
25.0 mm
(0.98")
37.0 mm
(1.46")
SI-QS90 Safety Interlock
Switches
SI-LS100 Safety Interlock
Switches
SI-LS31 Safety Interlock
Switches
SI-LS42 Safety Interlock
Switches
RP-LS42 Rope Pull Switches
Conduit Adaptor
(One supplied with each switch)
Model Size Thread Conversion Dimensions Used With
SI-QS-M20 ½ in-14 NPT
Plastic M20 × 1.5 to ½
in-14 NPT
25.0 mm
(0.98")
M20 x 1.5
24.0 mm
(0.94")
1/2"-14 NPT
Internal Thread
SI-QS90 Safety Interlock
Switches
SI-LS100 Safety Interlock
Switches
SI-LS31 Safety Interlock
Switches
SI-LS42 Safety Interlock
Switches
RP-LS42 Rope Pull Switches
Standards and Regulations
The list of standards below is included as a convenience for users of this Banner device. Inclusion of the standards below
does not imply that the device complies specifically with any standard, other than those specified in the Specifications
section of this manual.
U.S. Application Standards
ANSI B11.0 Safety of Machinery; General Requirements and Risk Assessment
ANSI B11.19 Performance Criteria for Safeguarding
ANSI NFPA 79 Electrical Standard for Industrial Machinery
International/European Standards
ISO 12100 Safety of Machinery – General Principles for Design — Risk Assessment and Risk Reduction
ISO 14119 (EN 1088) Interlocking Devices Associated with Guards – Principles for Design and Selection
ISO 14120 Safety of machinery – Guards – General requirements for the design and construction of fixed and movable
guards
ISO 13857 Safety Distances . . . Upper and Lower Limbs
IEC 62061 Functional Safety of Safety-Related Electrical, Electronic and Programmable Control Systems
ISO 13849-1 (EN 954-1) Safety-Related Parts of Control Systems
IEC 60204-1 Electrical Equipment of Machines Part 1: General Requirements
IEC 60947-1 Low Voltage Switchgear – General Rules
IEC 60947-5-1 Low Voltage Switchgear – Electromechanical Control Circuit Devices
IEC 60529 Degrees of Protection Provided by Enclosures
IEC 61508 Functional Safety of Electrical/Electronic/Programmable Electronic Safety-Related Systems
Safety Limit Switches
P/N 182190 Rev. A www.bannerengineering.com - Tel: +1-763-544-3164 15
EC Declaration of Conformity (DoC)
Banner Engineering Corp. herewith declares that the SI-LS31xxx series safety limit switches are in conformity with
the provisions of the Machinery Directive 2006/95/EC and all essential health and safety requirements have been met.
Representative in EU: Peter Mertens, Managing Director Banner Engineering Europe. Address: Park Lane, Culliganlaan 2F,
1831 Diegem, Belgium.
Banner Engineering Corp Limited Warranty
Banner Engineering Corp. warrants its products to be free from defects in material and workmanship for one year following
the date of shipment. Banner Engineering Corp. will repair or replace, free of charge, any product of its manufacture
which, at the time it is returned to the factory, is found to have been defective during the warranty period. This warranty
does not cover damage or liability for misuse, abuse, or the improper application or installation of the Banner product.
THIS LIMITED WARRANTY IS EXCLUSIVE AND IN LIEU OF ALL OTHER WARRANTIES WHETHER EXPRESS OR
IMPLIED (INCLUDING, WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE), AND WHETHER ARISING UNDER COURSE OF PERFORMANCE, COURSE OF DEALING OR
TRADE USAGE.
This Warranty is exclusive and limited to repair or, at the discretion of Banner Engineering Corp., replacement. IN NO
EVENT SHALL BANNER ENGINEERING CORP. BE LIABLE TO BUYER OR ANY OTHER PERSON OR ENTITY FOR
ANY EXTRA COSTS, EXPENSES, LOSSES, LOSS OF PROFITS, OR ANY INCIDENTAL, CONSEQUENTIAL OR
SPECIAL DAMAGES RESULTING FROM ANY PRODUCT DEFECT OR FROM THE USE OR INABILITY TO USE THE
PRODUCT, WHETHER ARISING IN CONTRACT OR WARRANTY, STATUTE, TORT, STRICT LIABILITY,
NEGLIGENCE, OR OTHERWISE.
Banner Engineering Corp. reserves the right to change, modify or improve the design of the product without assuming any
obligations or liabilities relating to any product previously manufactured by Banner Engineering Corp.
Safety Limit Switches
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