LINK Systems Max Presence Sensing Device - Manual (Page 40)

Link Lite Black Max Section 4 - Operating Instructions
4-7
4.2.4 Requirements for Safe Use of
Blanking
Since blanking leaves "windows" in the
Link Lite Black Max sensing field that
could allow a person to penetrate closer or
completely to the hazard before being
detected, the following blanking
requirements must be followed.
1. Always try to design and set up the
production system to avoid blanking any
Black Max sensors.
2. When a necessary obstruction blocks
part of the Black Max sensing field, all
Black Max sensor channels that can be left
active. NEVER blank any Black Max
sensor that can be left on!
3. If the obstruction that requires blanking
does not prevent entry through the blanked
area(s) of the sensing field by extending all
the way across the blanked area,
supplemental barriers must be used to
prevent a person from reaching through the
blanked area. Alternatively, if only FIXED
BLANKING is used in such a way that no
two side by side sensors are blanked, or if
VARIBLANK only is used, the safety
distance, Ds, can be increased by 2.55
inches to account for an increased M.O.S.
of .75 inches and no supplementary
barriers used. If no more than any two (2)
side by side sensor channels use FIXED
BLANKING, or if a combination of
VARIBLANK and FIXED BLANKING is
used so that no side by side channels use
FIXED BLANKING, the safety distance,
Ds, can be increased 5.1 inches to account
for an increased M.O.S. of 1.5 inches and
no supplementary barriers used. For any
pattern of FIXED BLANKING that blanks
more than two (2) side by side sensor
channels, the blanked area must be
obstructed to prevent a person from
reaching through the blanked area.
Otherwise item 4 of this list applies. For
any combination of VARIBLANK and
FIXED BLANKING that uses two or more
side by side sensor channels in FIXED
BLANKING, the fixed blanked area must
be obstructed to prevent a person from
reaching through the fixed blanked area
and the safety distance, Ds, must be
increased by 2.55 inches. Otherwise, item
4 of this list applies.
4. If any production job requires a set up,
including blanking, such that a person can
reach the hazard without being sensed by
the Link Lite Black Max at the required
safety distance, alternative OSHA or ANSI
accepted safeguarding devices or guards
must be used to protect personnel.
5. Close supervision of blanking must be
maintained. Only those persons trained
and authorized by the employer in the safe
use of blanking and required supplemental
or alternative safeguarding should be
allowed access to the blanking selection
key. The blanking selection key must never
be left in the blanking mode selector
switch.
WARNING! Failure to follow the
requirements for safe use of blanking
will leave personnel unprotected or
only partly protected from the hazard
for which protection is intended.
Serious injury or death may result
because a person may be able to reach
into the hazardous area while machine
action is in progress.