Banner EZ-SCREEN­ Safety Light Curtain Systems - Manual (Page 24)

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P/N 133487
Banner Engineering Corp. • Minneapolis, U.S.A.
www.bannerengineering.com • Tel: 763.544.3164
Overview
22
Banner Engineering Corp. • Minneapolis, U.S.A.
www.bannerengineering.com • Tel: 763.544.3164
EZ-SCREEN
Instruction Manual
Installation and Alignment
The formula used for U.S. applications (other standards may
apply) to calculate separation distance is:
Ds = K x (Ts + Tr) + Dpf
where:
Ds – the separation distance, in mm (inches);
K – 1600 mm per second (or 63" per second), the
OSHA1910.217, ANSI B11, ANSI/RIA R15.06
recommended hand-speed constant (See Note 1);
Ts – the overall stop time of the machine (in seconds) from
the initial “stop” signal to the final ceasing of all motion,
including stop times of all relevant control elements
(e.g., IM-T-.. Interface Modules) and measured at
maximum machine velocity (See Note 2 and Warning at
right).
Tr – the maximum response time, in seconds, of the
EZ-SCREEN emitter/receiver pair (see Section 2.1 for
SLS.. models and Section 7.5 for SLSC.. models); and
Dpf – the added distance due to depth penetration factor as
prescribed in OSHA1910.217, ANSI B11, ANSI/RIA
R15.06 for U.S. applications (See Caution below):
NOTES:
1. The OSHA-recommended hand speed constant K has
been determined by various studies, and although these
studies indicate speeds of 63"/second to more than 100"/
second, they are not conclusive determinations. Consider all
factors, including the physical ability of the operator, when
determining the value of K to be used.
2. Ts is usually measured by a stop-time measuring device.
If the machine manufacturer’s specified stop time is used,
at least 20% should be added to allow for possible clutch/
brake system deterioration. This measurement must take
into account the slower of the two MPCE channels, and the
response time of all devices or controls that react to stop the
machine. See Notice Regarding MPCEs. If all devices are
not included, the calculated separation distance (Ds) will
be too short and serious injury could result.
This example shows how to use the formula at left to
calculate separation (safety) distance (Ds). These numbers
will be used for the variables in the formula:
K = 63" per second (the hand speed constant set
by OSHA)
Ts = 0.32 (0.250 second is specified by the machine
manufacturer; plus 20% safety factor; plus
20 ms for interface module IM-T-9A response)
Tr = 0.023 second (the spec i fied response time of
an SLSP14-600 EZ-SCREEN System)
Our example uses a 600 mm system with 14 mm resolution
and Reduced Resolution ON, so Dpf is 3". Response time
for this example is 0.023 second.
Sub sti tute the numbers into the for mu la as fol lows:
Ds = K x ( Ts + Tr ) + Dpf
Ds = 63 x (0.32 + 0.023) + 3 = 24.6"
In this example, the EZ-SCREEN emit ter and re ceiv er
must be mount ed so that no part of the defined area will be
closer than 24.6" to the closest reachable hazard point on
the guarded ma chine.
Figure 3-2. Separation Distance (Ds) calculation example
Notice Regarding MPCEs
Each of the two Machine Primary Control Elements
(MPCE1 and MPCE2) must be capable of immediately
stopping the dangerous machine motion, irrespective
of the state of the other. These two channels of
machine control need not be identical, but the stop time
performance of the machine (Ts, used to calculate the
separation distance) must take into account the slower
of the two channels (see Section 3.5.3).
Reduced
Resolution
Depth Penetration Factor (Dpf)
14 mm Systems 30 mm Systems
OFF 24 mm (1") 78 mm (3")
ON 78 mm (3") 180 mm (7")
WARNING . . .
Determine Correct Stop Time
Stop time (Ts) must include the response time of all devices
or controls that react to stop the machine. If all devices are
not included, the calculated safety distance (Ds) will be too short.
This can lead to serious bodily injury or death. Be sure to include
the stop time of all relevant devices and controls in your
calculations.
WARNING . . .
Proper Installation When
Using Reduced Resolution
Reduced Resolution increases Dpf (see values in table). Increase
the depth penetration factor to calculate the proper separation
distance whenever Reduced Resolution is used. Always turn
Reduced Resolution OFF when the larger minimum object detection
size is not required.