Overview, Cascadeable ez-screen, 9 positive-opening safety interlock switches – Banner EZ-SCREEN Low-Profile Safety Light Curtain Systems User Manual

Page 66: Warning

Advertising
background image

64

P/N 133487

Banner Engineering Corp.

Minneapolis, U.S.A.

www.bannerengineering.com • Tel: 763.544.3164

Overview

64

P/N 140044 rev.

E

Banner Engineering Corp.

Minneapolis, U.S.A.

www.bannerengineering.com • Tel: 763.544.3164

EZ-SCREEN LP

Instruction Manual

Cascadeable EZ-SCREEN

7.9 Positive-Opening Safety Interlock Switches

The Cascade input may be used to monitor interlock safety

gates or guards. Requirements vary widely for the level of

control reliability or safety category (per ISO 13849-1) in the

application of interlocked guards. While Banner Engineering

recommends the highest level of safety in any application, it

is the responsibility of the user to safely install, operate, and

maintain each safety system and comply with all relevant laws

and regulations. Of the following applications, Figure 7-9 meets

or exceeds the requirements for OSHA/ANSI control reliability

and Safety Category 4, per ISO 13849-1.

The safety switches and actuators used with the Cascade must

be designed and installed so that they cannot be easily defeated.

They must be mounted securely, so that their physical position

can not shift, using reliable fasteners that require a tool to

remove. Mounting slots in the housings are for initial adjustment

only; final mounting holes must be used for permanent location.

Positive-Opening Interlocking Safety Switches

Two individually mounted safety interlock switches are

recommended for each guard to meet Category 4, per ISO

13849-1, and must satisfy several requirements. Each switch

must provide at minimum, one normally closed (N.C.) electrically

isolated contact to interface with the Cascade input (see

Figure 7-9).
The contacts must be of “positive-opening” design, with one or

more normally closed contacts rated for safety. Positive-opening

operation causes the switch to be forced open, without the use of

springs, when the switch actuator is disengaged or moved from

its home position (see the Banner Safety Catalog for examples).

In addition, the switches must be mounted in a “positive mode”

to move/disengage the actuator from its home position and open

the normally closed contact when the guard opens.

Figure 7-9. Monitoring two positive-opening safety switches

Interlock Guarding Requirements

The following general requirements and considerations apply to

the installation of interlocked gates and guards for the purpose

of safeguarding. In addition, the user must refer to the relevant

regulations to be sure to comply with all necessary requirements.
Hazards guarded by the interlocked guard must be prevented

from operating until the guard is closed; a Stop command must

be issued to the guarded machine if the guard opens while the

hazard is present. Closing the guard must not, by itself, initiate

hazardous motion; a separate procedure must be required to

initiate the motion. The safety switches must not be used as a

mechanical or end-of-travel stop.
The guard must be located an adequate distance from the

danger zone (so the hazard has time to stop before the guard

is opened sufficiently to provide access to the hazard), and it

must open either laterally or away from the hazard, not into the

safeguarded area. Depending on the application, an interlocked

gate or door should not be able to close by itself and activate

the interlocking circuitry (ANSI/RIA R15.06). In addition, the

installation must prevent personnel from reaching over, under,

around, or through the guard to the hazard. Any openings in the

guard must not allow access to the hazard (see ANSI B11.19 or

the appropriate standard). The guard must be strong enough and

designed to protect personnel and contain hazards within the

guarded area, which may be ejected, dropped, or emitted by the

machine.

WARNING . . .

Unguarded Moving Parts

It must not be possible for personnel to reach any hazard point
through an opened guard (or any opening) before hazardous
machine motion has completely stopped.
Please reference OSHA CFR1910.217, ANSI B11 standards, or
other appropriate standards for information on determining safety
distances and safe opening sizes for your application (see Inside
back cover).

Wh

Open

Bk

Bn

Bu

NOTE: This application is considered

to meet or exceed requirements
for OSHA/ANSI control reliability
and Category 4 per ISO 13849-1.

RDLP6G-4..D

RDLP6G-4..D Cordset Pinout*

Brown Ch 1a

White Ch 2a

Blue Ch 2b

Black Ch 1b

* Other cordset options may also be used; see Figure 7-8 for more

information.

Advertising