Rockwell Automation 445L GuardShield Safe 4 and Safe 4 PAC Safety Light Curtains User Manual - Manual (Page 8)

R
GuardShield™ Safe 4 Safety Light Curtain User Manual
6
Original instructions
Examples of Range of Use
The GuardShield Safe 4 safety light curtain operates as a proper
protective device only if the following conditions are met:
• The control of the machine must be electrical.
• The controlled machine must be able to be stopped any
where in the machines stroke or cycle.
• The transmitter and receiver must be mounted such that
access to the hazard is only through the light curtain’s
protective field.
• The restart button must be located outside the hazardous
area such that it cannot be operated by a person working
inside the hazardous area.
• The statutory and local rules and regulations must be
observed when installing and using the device.
GuardShield Safe 4 Laser Alignment
The laser light source in the Integrated Laser Alignment system of
the GuardShield Safe 4 light curtains is a Class 2, eye safe laser
diode with a wavelength of 630 nm.
This Class 2, eye safe laser is switched from a low output power
state to a high output power state (and back again) by means of
control circuitry which detects reflected laser light from a
temporary blockage of the emitted laser light. This is most
commonly accomplished by a person’s finger placed over the
laser overlay window. There is also an automatic shutdown
feature that switches the laser diode from the high power state to
the low power state if there is no finger or other interruption
detected for a period of five minutes.
During the high output mode of operation, the laser is pulsed at a
rate of approximately 2 Hz in order to facilitate finger detection in
high ambient light conditions.
Safety Functions
All GuardShield Safe 4 safety light curtains operated as on/off
devices, meaning the OSSD outputs switch off/on according to an
obstruction or clearing of the detection field.
System Testing
The GuardShield Safe 4 performs a complete system self-test at
power up and switches to the ON state if the system is properly
aligned and the protective field is unobstructed.
External Test (Machine Test Signal)
Normally the test input at the transmitter is installed with a short-
circuit jumper to activate the transmitter. A test cycle of the
system can be triggered by an external test signal to the
GuardShield Safe 4 transmitter. Supplying or removing a signal
(+24V DC) via a N.C. or N.O. switch at the test input deactivates
the transmitter for the duration of the test signal, simulating an
interruption of the protective sensing field (see also page 11).
Response Time
The response time of the GuardShield Safe 4 safety light curtain
depends on the height of the protective field, the resolution, and
the number of light beams (see table on page 20).
Determining the Safety Distance
The light curtain must be mounted with proper safety distance
• From the point of danger
• From reflecting surfaces
US Safety Distance Formula
This distance, referred to as the safety distance, must be properly
calculated prior to determining the safety light curtain protective
height and mounting the light curtains on the machine. Failure to
properly calculate this safety distance may result in operator
injury.
In the United States there are two formulas that are used to
properly calculate the safety distance. The first, the OSHA formula,
is the minimum requirement for the calculation of the safety
distance. The second formula, the one recommended by Rockwell
IMPORTANT
Additional measures may be necessary to
ensure that the ESPE does not fail to danger
when other forms of light radiation are
present in a particular application (i.e., use of
cableless control devices on cranes, radiation
from weld spatter or effects from strobe
lights).
Class 2 Laser
To prevent exposure to laser radiation, do
not expose your eyes to the laser. Turn ILAS
off if not in use.
IMPORTANT
The protective system must be tested for
proper operation after each and every
change to the configuration.
IMPORTANT
Determining Stop Time: The measurement of
stopping time (Ts) must include the stopping
times of all devices in the stop circuit. Not
including all device and control system
elements when calculating Ts will result in an
inaccurate safety distance calculation.
ATTENTION
The GuardShield Safe 4 safety light curtains
must be mounted at a sufficient distance
from the pinch point or point of operation
hazard to help ensure that the machine stops
before a person’s finger, hand, arm(s), or body
reaches the hazard.
IMPORTANT
Regardless of the calculated safety distance,
GuardShield Safe 4 safety light curtains
should never be mounted closer than six
inches from the point of operation or pinch
point hazard.