S
51 Posts in this encyclopedia categorySafe Direction (SDI)
The SDI function prevents a motor from moving in an invalid direction. [DIN EN 61800-5-2]
Safe Limited Speed (SLS)
The SLS function prevents the motor from exceeding the specified speed limit. [DIN EN 61800-5-2]The
function allows monitoring of an axis or spindle for a given speed.
During set-up, for example, the speed limits according to the applicable
C standard are to be applied, e.g. 2 m/min for axes. In many machines,
however, a safely monitored speed is also applied during automatic
machining. In order to avoid damage to the machine or the production
goods, exceeding certain maximum speeds and velocities can be safely
prevented.The drive manufacturer must provide protective measures
that only allow the machine manufacturer to change the speed limit
values. After each new setting or change of speed limit values, an
acceptance test must also be carried out. During the acceptance test,
the commissioning engineer must approach the speed limit value and
document the correct safety-related reaction on a form provided by the
drive manufacturer.
Safe Operating Stop (SOS)
The SOS function prevents the motor from deviating from the stop
position by more than a set amount. The PDS(SR) provides the motor with
the energy to enable it to withstand the application of external forces.
[DIN EN 61800-5-2]The
drive is kept at a standstill by its control system. The higher-level
SAG initiates the safety-related reaction in the event of deviations
from standstill. The safe operating stop is always required where there
is frequent manual intervention in the process and a hardware separation
from the power supply is not practicable. Examples of applications are
set-up operation and the running-in of CNC programmes.
Safe separation
Safe isolation of circuits exists when a single fault does not lead
to the voltage crossing over into that of another circuit. Safe
isolation is defined according to IEC/EN 61140, IEC/EN 60947-1 in
conjunction with IEC 60664-1 and is specified as rated impulse with
respect to the degree of pollution. The rated impulse withstand voltage
is the voltage value according to which the clearances and creepage
distances are rated. It is determined depending on the overvoltage
category to which the electrical equipment is assigned.
Safe shutdown
A stop of the drive corresponding to the hazardous situation (stop
function). The electrical, electronic, electromechanical devices
necessary for decelerating the drive must be included in the safety
considerations.Measures are e.g.Controlled stop with safely monitored deceleration timeControlled stopping with safe monitoring of the braking rampUncontrolled stopping with mechanical brakes
Safe Speed Monitor (SSM)
The SSM function provides a safe output signal to indicate if the motor speed is below a specified limit. [DIN EN 61800-5-2]
Safe Speed Range (SSR)
The SSR function keeps the motor speed within specified limits. [DIN EN 61800-5-2]
Safe Torque Off (STO)
No energy is supplied to the motor that can cause rotation (or motion
in the case of a linear motor). The PDS(SR) does not supply energy to
the motor that can cause torque (or force in the case of a linear
motor).
Safely reduced speed
Safe monitoring of the speed of a drive.The function allows
the monitoring of an axis or spindle for a given speed. During set-up,
for example, the speed limits according to the applicable CNorm are to
be applied, e.g. 2 m/min for axes. In many machines, however, a safely
monitored speed is also used during automatic machining. In order to
avoid damage to the machine or the production goods, exceeding certain
maximum speeds and velocities can thus be safely prevented.
SAFEMASTER S
The speed monitors of the SAFEMASTER S series detect and signal the
standstill and speed of machines and systems in automatic as well as in
set-up mode.
Safety device
Technical means to prevent hazards to people, production goods and the environment.
Safety gate guard
Safety gate monitors monitor the position of movable safety guards.
They are used wherever access in a room with hazardous movement requires
protection.
Safety gate monitoring
The ready-to-connect, DIN-rail mountable safety gate monitors monitor
the position of movable safety guards. They are used wherever access or
entry in a room with hazardous movement requires safeguarding, e.g. for
machine operation, set-up or troubleshooting. For this purpose, the
safety gate monitoring modules monitor the position of movable safety
switches that are actuated by the opening or closing of the safety
guard.See also safety switch, solenoid interlock
Safety Integrity Level (SIL)
Target measure of the probability of failure for the execution of the risk-reducing functions [IEC / DIN EN 61508].
Safety light grid / safety light curtain
Safety light grid or safety light curtain changes its switching state when one or more light beams are interrupted.
Safety Mats, Safety Panels Safety Edges, Safety Edges
Safety mats, safety edges change their switching state when stepped on
(safety mat) or when deformed (safety edges) [EN 1760-1/-2].
Safety relay
The so-called safety relays, i.e. relays with mechanically forcibly
guided contacts according to DIN EN 61810-3, are used wherever people,
machines and valuable goods have to be protected against damage and
injury. Such a relay consists of at least one NC contact and one NO
contact and is constructed in such a way that the NC contact and the NO
contact are never closed at the same time.In safety-relevant
applications where relays with forcibly guided contacts (according to
DIN EN 61810-3) are used, special attention is paid not only to the high
switching reliability but also to the compact design. In addition,
these relays are characterised by high vibration and shock resistance.
Safety switch
Safety switches protect accesses and safety doors or flaps on machines
and systems and are suitable for safety applications up to Cat. 4 PL e
in accordance with EN ISO 13849-1 without false rejection. Safety
switches are suitable for safeguarding protective devices such as safety
doors or protective grids that only provide the necessary safety when
closed.
Safety switch with separate actuator
Safety switches with separate actuator are used to safeguard safety
guards that can be rotated, removed or moved sideways and only provide
the required safety when closed. Dangerous movements are immediately
switched off and secured against restarting when the safety guard is
opened.
Safety switchgear
Safety switchgear such as emergency stop modules, standstill
monitoring and speed monitoring, multifunctional safety switchgear as
well as safety systems ensure fast and reliable drive monitoring of
machines and plant and thus serve to protect and ensure the safety of
electrical consumers.
Secure hold
Safe interruption of the power supply to the drive, which is why no
torque is generated and thus no dangerous movement occurs. Monitoring of
the standstill does not have to take place. A contact-based separation
to the energy supply can, but does not have to be present.
Security module
The safety module is used to protect persons and machines by
safety-related enabling and interrupting of safety circuits. Up to two
independent safety functions can be realised in just one device. In
addition to the safety functions emergency stop, safety door, antivalent
safety sensor, two-hand or light barrier, your safety-related safety
mats and safety edges can also be connected.In addition to the manual and automatic start, the common manual start can also be selected for both safety functions.
Separating protective device
Mechanical separation between the hazardous area and the operational environment.The
separation can be in the form of a safety guard, safety door,
enclosure, cover, covering, fence, screen, etc. It can be independent or
part of the machine. It can be independent or part of the machine.
Shutdown in an emergency
An action in an emergency designed to stop a process or movement that has become hazardous.
Simultaneity monitoring
The simultaneity monitoring of signal transmitters by the
safety-relevant evaluation unit is used to increase the functional
safety of the safety guard. The monitoring is carried out by checking
the signal change of the sensors within the specified time, the
synchronous monitoring time. If this time is exceeded, no enable signal
is given. Simultaneity monitoring is prescribed for some safety devices
Soft start / soft stop
The drive can start/stop without jerks and the drive elements are not
damaged, i.e. maximum protection for the mains, motor and machine.
Starting time and coasting torque are adjustable via potentiometer.
Soft starter
The soft starter is a robust electronic control unit for soft starting
of motors with integrated monitoring functions. To operate the motor
reliably, it provides soft start, motor protection, voltage and phase
sequence monitoring in just one device.
Soldering
Soldering of the relays by hand as well as in common wave soldering
machines is possible. The maximum temperature and soldering time
specified in the corresponding data sheet must not be exceeded. In wave
soldering systems, we recommend preheating at a maximum of 130 °C. The
time should be selected so that the relay just reaches this temperature.
The time should be chosen so that the relay just reaches this
temperature. A possible soldering profile is listed in the standard DIN
EN 61810-1, Annex N. If a flux is used, it must not be aggressive or
acidic. Also, only the underside of the PCB should be wetted.
Solenoid interlock
Solenoid interlocks (guard locking) combine the proven functional
principle and the advantages of electromechanical safety switches with
2-channel guard locking function. Thanks to guard locking monitoring,
they can be used for both process and reliable personal protection.
Different coding levels, very high guard locking forces and extensive
diagnostic options enable use in almost any safety-relevant application.
Solid state relay
The solid-state relay is used for current monitoring, load control or
analogue control, and can also be reliably adjusted to meet individual
requirements. It is characterised by wear-free and noiseless switching
and is able to safely and reliably withstand repeated loads as well as
high temperatures. The unit offers quick and easy installation due to
its ready-to-use design and can thus be plugged in and connected
directly.In addition, the unit can be mounted directly on
existing cooling surfaces. It is also available as a solid-state
contactor with a correspondingly pre-dimensioned heat sink and can be
easily snapped onto a top-hat rail.
Solid-state contactor
The solid-state contactor has been specially developed for switching
resistive and inductive three-phase loads and therefore serves as an
electronic contactor replacement. The DCB technology (Direct Copper
Bonding) ensures optimum heat transfer, which allows switching of large
load currents and at the same time guarantees high reliability and
robustness.
Speed monitor
Speed monitors offer a convenient solution for safety-related speed
monitoring, as used in wind turbines, centrifuges or stage technology.
Standstill / overspeed and underspeed are reliably monitored in both
automatic and set-up mode.The speed monitor is used in machines
and systems where machine movements or moving parts can pose a risk to
people and machines. For example, the safe monitoring of the reduced
working speed in set-up mode increases the safety of the operating
personnel. It also increases productivity by preventing unnecessary
shutdowns.
Speed monitoring
Safety-related monitoring of a defined speed. If this speed is exceeded
or undershot, the drive is switched off or a message is sent.
Standstill monitor
The sensorless safety-related standstill monitor detects the
standstill of 3-phase and 1-phase motors independent of the direction of
rotation without having to resort to additional external sensors such
as encoders or proximity switches. Standstill is detected directly by
evaluating the voltages at the motor terminals.
Star-delta time relay
When the operating voltage is applied, the star contact is closed.
After the set wiping time has elapsed, the star contact opens and after a
short pause (contact turnover time 35 to 100 ms) the delta contact
closes.
Start-up interlock
Device that prevents automatic machine start-up when the power supply to
the SAG is switched on or interrupted and switched on again.
Start-up test
Manual or automatic test of the SAG after the supply voltage has been
applied to the SAG. An example is the manual opening and closing of an
isolating protective device after the supply voltage has been switched
on.
Static coupling relays
With the static coupling relays imod and omod, safe (electrical)
isolation is achieved by an optocoupler. The signal entering the
coupling relay is conditioned in several stages to obtain a suitable
low-voltage signal for controlling the actual switching element at the
output of the module.In the process, interference due to stray
capacitance, as occurs with cables running in parallel, as well as HF
and transient interference (short-term voltage peaks) are largely
filtered out. The processed signal is fed to an optocoupler. This
consists of a luminescent diode (LED) and a phototransistor. They are
used to galvanically isolate the input and output signal. Instead of the
switching contact in electromechanical relays, a semiconductor output
is used in static relays. In DC output modules this is a transistor, in
AC output modules triacs are used.Their advantages include:long service lifeshort switching timesbounce-free, noiseless switchinglow drive power
Stop category 0
Uncontrolled shutdown by immediately switching off the power to the machine drive elements.
Stop category 1
Controlled shutdown in which the energy supply is only interrupted when standstill is reached.
Stop category 2
Controlled shutdown in which the energy supply is maintained at standstill.
Switch off in an emergency
Emergency action intended to cut off the supply of electrical energy
to all or part of an installation if there is a risk of electric shock
or any other risk of electrical origin [IEC / DIN EN 60204-1/121.98
Annex D].It is intended to avert or reduce emerging or existing
hazards to persons and damage to the machine, the work material or the
environment.
Switchgear
Switching devices are all electrical components and devices that serve
to switch on and off as well as to protect and ensure the safety of
electrical consumers, such as emergency stop modules, standstill
monitors and speed monitors as well as multifunctional safety
switchgear.
Synchronous monitoring time
Time during which simultaneous actuation must occur to generate an output signal.Discrepancy time monitoringTwo-hand control