Rockwell Automation Allen-Bradley Guardmaster GuardShield 440L-AGST Series Installation Instructions

Installation Instructions
Original Instructions
GuardShield Washdown Enclosure
Catalog Number 440L-AGSTxxx
Topic
Description
Optical Properties
Assembly Procedure
Cleaning
Replacing the Acrylic Tube
Dimensions [mm (in.)]
Description
The GuardShield™ washdown enclosure is designed to provide an
environmentally protective enclosure for the standard GuardShield
family of safety light curtains, which are applied in washdown
applications. These applications are typically found in the food and
beverage industry.
These acrylic tubes are sold in pairs and provide protection for
GuardShield Type 4 POC and the GuardShield PAC light curtains. The
enclosures come with acetal endcaps and stainless steel mounting
brackets. Enclosures are offered in protective heights from
320...960 mm (12.6...37.79 in.).
The GuardShield washdown enclosures meet the IP67 requirements per
IEC 60529 and 1200 psi washdown.
GuardShield safety light curtains must be properly assembled according
to the procedure that is described in this document and mounted in
accordance with the requirements that are detailed in publication
440L­IN012.
Optical Properties
The GuardShield safety light curtain is a Type 4 ESPE per IEC 61496
Parts 1 and 2. As such, the GuardShield Type 4 meets the IEC 61496
optical angular divergence emission and reception requirements of
± 2.5°. When the GuardShield Type 4 POC and PAC light curtains are
assembled into the acrylic tube, the optical emission and reception
(EAA) meet the requirements of a Type 2 device, for instance ± 5°. The
result is that the infrared light is emitted over a greater angle of
divergence, which can increase the possibility of optical reflection of the
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infrared light off a reflective surface.
1
1
ATTENTION: If the transmitted infrared light is reflected off of a
2
shiny surface and is, then seen by the receiver, it is possible that an
2
object can penetrate further into the protective field of the
GuardShield before being detected.
2
3
It is necessary to first properly calculate the required safety distance for
the particular application, determine the protective height of the
GuardShield, and then calculate the distance (a) from the formula in
Figure 2 - Minimum Distance from Reflecting
GuardShield can be required to be mounted at the greater calculated
distance from the point of operation hazard based on this reflective
distance.
Figure 1 - Distance to Reflective Surface
Figure 2 - Minimum Distance from Reflecting Surfaces
a (mm)
1600
1500
1400
1300
1200
1100
1000
900
800
700
600
500
400
300
200
100
Note: Formula: a = tan 5.0° x D (mm)
a = Minimum distance to reflective surfaces (mm)
D = Distance between transmitter and receiver (m)
Surfaces. The
a
Distance D (meters)
3 5 10 15
D (m)
20