MRK-12 BERNSTEIN WERKZEUGFABRIK, MRK-12 Datasheet

MRK-12

Manufacturer Part Number

MRK-12

Description

SAFETY SWITCH, MAGNETIC, 2NO/1NC

Manufacturer

BERNSTEIN WERKZEUGFABRIK

Datasheet

1.MRK-11.pdf (2 pages)

Specifications of MRK-12

Contact Voltage Dc Max

100V

Contact Current Dc Max

Switch Terminals

Lead

Svhc

No SVHC (15-Dec-2010)

Contact Configuration

3PST-1NC/2NO

Contact Rating

External Depth

20.5mm

Current page: 1 of 2
Download datasheet (115Kb)

MRK Safety Interlock Switches are designed to conform with the

European standards for the "Safety of Machinery" which have

been derived from the European Directives 89/392/EEC,

91/368/EEC and 93/44/EEC. BSI Testing have type tested the

Safety Interlock Switches to show conformity with the Supply of

Machinery (Safety) Regulation 1994 (SI 2063). The standards

used for these tests were: BS 3955 1986, BS 5304 1988 and BS

EN 1088.

MRK Safety Interlock Switches provide safe interlocking of fixed

and moveable guards, access panels and doors etc. These

devices are very tolerant to misalignment and are particularly

suited to environments that are contaminated by solids, dust or

liquid and where non contact interlocking is required.

MRK Safety Interlock Switch consists of two parts, the switch

housing with a connection cable and the magnetic actuator. The

Interlock contact operates (closes) when the actuator is in close

proximity to the switch housing, see figure 1. An auxiliary contact

that works in the oppesite mode is provided to enable automatic

monitoring. The auxiliary contact is not fused. The operating

distances shown in table 1 apply to situations where the switch

and actuator are not mounted on, or near to ferrous surfaces.

When mounted on or near ferrous surfaces the operating

distance will be reduced. Avoid close proximity to strong

magnetic fields i.e. electric motors and solenoids.

The switch can be operated through a non ferrous skin such as

non magnetic stainless steel, plastic, aluminium and non ferrous

castings etc. possibly enabling the switch and its connections to

be inside part of the machine.

It should be noted that the Interlock Switch function is to provide

safe interlocking as detailed above, the device should not be

used or relied on as an emergency stop control.

To aid selection, listed in table 1 are the various Safety Interlock

Switch types. The suitability for any safety related device must

be confirmed by a risk assessment for each application.

If inductive loads are to be switched the Interlock switch contacts

must be protected either with a reverse polarity diode across the

inductive load, a suitable CR network or a varistor. If the load is

of a capacitive nature i.e. more than a 25 metre cable run, then a

suitable CR network should be used.

contact life and reliability, ensure that the maximum load ratings

are not exceeded.

contact our technical department.

When considering a fixing position refer to "Principles of

operation and use", also consider the placement of the

Interlock Switch with a view to making it difficult to defeat the

switch, see BS EN 1088.

Ensure that the vibration limits will not be exceeded both in

normal and in any foreseen abnormal operation. If vibration is a

problem the switch unit may be mounted on a rubber block (at

least 87 L x 23 W x 8 D mm) to reduce the affects of vibration.

The switch and actuator should not be fixed so that they slide

longitudinally against each other, as multiple operation may

occur.

Installation Instructions For MRK Safety Interlock Switches

Overview

Principles of operation and use

Loads

Fitting and adjustment

For technical advice on specific loads,

To ensure maximum

Bernstein Ltd Westgate Aldridge West Midlands

Tele 01922 744999 Fax 01922 457555

WS9 8EX

The Safety Interlock Switches must be fitted with appropriate

security screws (M4 x 20 mm minimum) to avoid unauthorised

personnel adjusting or removing them. The security screw driver

should be kept by a person authorised to maintain the switches.

Suitable security screws and drivers are available from RS

Components Ltd, RS Part number 279-414.

When adjusting the MRK Interlock Switch for maximum

operation distance it is recommended that the switch is

magnetically overdriven by at least 25% i.e. With an application

that gives a maximum operating distance of 16 mm it should be

considered that the maximum distance is actually 16 mm less

25% = 12 mm, therefore to operate the switch correctly the

actuator magnet should be within 12 mm of the switch.

Consideration should be given to the safe routing of the

connecting cable, avoid cable runs where mechanical damage to

the cable may occur, if this is likely a Copex gland may be fitted

so that the cable may be routed in conduit - only on cable

versions. BH versions use Brad Harrison connectors. Ensure

that the electrical connections are made as in the table 2, check

that the contact ratings are not exceeded, table 1.

Interlock switch contacts are protected by a non reset fuse it is

recommended that these contacts are externally fused at 75% of

the internal fuse value. Use HBC quick blow fuses.

Ensure that any spare actuators are removed from the

installation site and are held only by authorised personnel and

not the machine operators, also remove any magnetic material

that might insight an operator to try and defeat the Interlock

Switch.

Ensure that the machine is in a safe condition before any

maintenance is carried out, refer to the machine's instructions on

how to achieve this.

The Interlock Switch should be routinely checked to verify its

continued operation, the frequency of these checks must be

decided by the manufacturer of the machine, although it is

recommended that these checks are carried out at least

monthly.

The switch and actuator may be cleaned if required using warm

water and detergent, if removal of the Interlock Switch is

required follow "4. Fitting and adjustment" for re fitting.

Examine the connecting cable for wear and tear and replace the

switch if the cable is damaged.

Order Codes

Type

MRK-11

MRK-12

MRK-11BH

MRK-12BH

MRK-AM

Maintenance

Description

1 n/o + 1 n/c contact c/w MRK-AM

2 n/o + 1 n/c contact c/w MRK-AM

1 n/o + 1 n/c contact c/w MRK-AM – Brad Harrison

connector

2 n/o + 1 n/c contact c/w MRK-AM – Brad Harrison

connector

Spare actuator for above

INT/INS/2000/1

As the

Page 1

Related parts for MRK-12

MRK-12 Summary of contents

Page 1

... Examine the connecting cable for wear and tear and replace the switch if the cable is damaged. To ensure maximum Order Codes Type MRK-11 MRK-12 MRK-11BH MRK-12BH MRK-AM Bernstein Ltd Westgate Aldridge West Midlands WS9 8EX Tele 01922 744999 Fax 01922 457555 Description 1 n n/c contact c/w MRK- n/c contact c/w MRK- n/c contact c/w MRK-AM – ...

Page 2

... Release time, 1 metre per second removal Operating Positions Operating relationship between the switch and actuator Figure 1 Actuator Actuator Switch * Actuator MRK- normally open 0.1A inductive 12.5 F/C 1. ½ inch UNF 6 Pole Table 2 3 metre 6 core Device/Contact 9mm ...

Related keywords

MRK-12 datasheet
MRK-12 data sheet
MRK-12 pdf datasheet
MRK-12 component
MRK-12 part
MRK-12 distributor
MRK-12 RoHS
MRK-12 datasheet download