EUCHNER ESM-2H2 User Manual

2-Hand Safety Relay, Series ESM-2H2..

User Information

Correct Use

Features

Function

The ESM-2H2.. 2-hand safety relay is an extremely
compact, universal safety two-hand control unit. It
complies with EN574, Typ III C, and is intended for use
in safety circuits that are designed in accordance with
EN 60204-1, e.g. on presses, punches and bending
tools. Due to the internal error monitoring, the 2-hand
safety relay can be used, despite very compact dimen­sions, for all applications up to the highest safety cate­gory 4 and PL e according to EN ISO 13849-1, SILCL 3
according to EN 62061 or Typ III C according to EN 574.

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2 safe, redundant relay outputs

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Cyclical monitoring of the output contacts

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Feedback loop for monitoring downstream contactors or
expansion modules

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Short circuit and earth fault monitoring

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Extrem compact housing

The EUCHNER 2-hand safety relay ESM-2H2.. is suitable
for setting up and monitoring two-hand circuits and is used
to protect the operators. Dangerous work steps can only be
triggered when both two-hand buttons connected are ope­rated simultaneously, i.e. within 0.5s.

It is to be ensured a single fault or a malfunction does not
result in the loss of the safety function and every fault is
detected by the cyclic self-monitoring at the latest prior to
the next actuation.

When the operating voltage is applied to A1-A2 and the
feedback loop X1-X2 is closed, the ESM-2H2.. is ready for
use. To be able to initiate a switching operation, the output
relays must be de-energized. The output relays only switch
to the energized position when the two-hand buttons T1
and T2 are operated simultaneously, i.e. within 0.5s.

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Up to PL e, SILCL 3, category 4

Fig. 1 Block diagram ESM-2H2..

(not dor plug-in terminals)

Installation

Safety Precauti­ons

Electrical Connec­tion

The output relays are not switched if:

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only one two-hand button is actuated or the time between the actuation of the 2 two-hand buttons is greater than 0.5s,

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the feedback loop is open (fault in the external contactor),

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another error (short circuit, cable break, error in the switching device) has occurred.

When T1 and/or T2 are/is released, the output relays opens immediately. In order to trigger a new operation, both two-hand
buttons must first be released and the feedback loop must be closed.

As per DIN EN 60204-1, the device is intended for installa­tion in control cabinets with a minimum degree of protection
of IP54. It is mounted on a 35-mm DIN rail according to
DIN EN 60715 TH35.

Fig. 2 Installation/removal

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Installation an setup are only allowed to be undertaken
by trained personell.

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The electrical connection is only allowed to be made with
the device and wiring isolated.

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The wiring must comply with the instructions in this user
information, otherwise there is a risk that the safety
function will be lost.

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As per EN 60204-1 the device is intended for installation
in control cabinets with a minimum degree of protection
of IP54.

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When the 24V version is used, a safety transformer
according to EN 61558-2-6 or a power supply unit with
electrical isolation from the mains must be connected.

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External fusing of the safety contacts (4A slow-blow or
6A quick-action or 10A gG) must be provided.

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A maximum length of the control lines of 1000 meters
with a line cross section of 0.75 mm2 must not be excee­ded.

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The line cross section must not exceed 2.5 mm2.

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If the device does not function after commissioning, it
must be returned to the manufacturer unopened. Ope­ning the device will void the warranty.

It is not allowed to open the device, tamper with the devi­ce or bypass the safety devices.

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All relevant sefety regulations and standards are to be
observed.

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The overall concept for the control system in which the
device is integrated is to be validated.

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Failure to observe the safety regulations can result in
death, serious injury and serious damage.

A1: Power supply
A2. Power supply
S11: Control line T1
S12: Control line T1
S13: Control line T1
S21: Control line T2
S22: Control line T2
S23: Control line T2
X1; X2: Feedback loop
13-14: Safety contact 1
23-24: Safety contact 2

Fig. 3 Connections

EUCHNER GmbH + Co. KG Kohlhammerstraße 16 D-70771 Leinfelden-Echterdingen Tel. [phone] Fax [phone] www.euchner.de [e-mail]

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2-Hand Safety Relay, Series ESM-2H2..

User Information

Applications

Feedback loop

Installation

The arrangement of the two-hand buttons must be designed in accordance with the standard EN 574 such that accidental
actuation or simple bypassing of the safety function is excluded.

The ESM-2H2.. unit is provided for the connection of 2-hand push-buttons, with one normally open or one normally colsed
contact.

Figur 1 shows the wiring of the ESM-2H2.. with a 2-hand push-buttons:

Jumper X1-X2:
See description

ESM-2H2..

Fig. 1:

Wiring of the ESM-2H2.. with a 2-hand push

-buttons

Fig. 2: Feedback loop

Contactors connected to the ESM-2H2.. or the basic devices
are monitored via the feedback loop of the basic device. KA
and KB are the positively driven contacts of the connected
contactor or expansion module.

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Avoiding unintentional actuation or bypassing of the safety device

The arrangement of the two-hand buttons must be designed in accordance with the standard EN 574 such that accidental
actuation or simple bypassing of the safety function is excluded.

The operation of both buttons using one hand must be prevented by an adequate distance (at least 260mm) or by a separa­ting wall. Actuation using forearm, elbow, knee, hip or other parts of the body can be effectively prevented by a further inc­rease in the distance between the two buttons, adequate distance from the floor and/or covers and/or separating walls.

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Example

Commissioning
Procedure

Distance from the two-hand buttons to the danger area

It is necessary to maintain a minimum distance between the buttons for the two-hand circuit and the danger area on the
machine or plant so that, after the release of one or both buttons, the machine or plant can only be reached once the dange-

rous movement has been interrupted or completed. According to the standard EN 999, the distance is calculated with the
following equation:

S = (K · T) + C
S: Minimum distance from the nearest pushbutton (two-hand button) to the danger area.
K: Parameter in mm/s, derived from data on the approach speeds of the body or parts of the body, for two-hand circuits

1600mm/s.
T: The overtravel of the overall system in seconds, that is the time from releasing the two-hand button to the end of the dan
gerous movement.
C: Additional distance in mm that based on entry into the danger area prior to the triggering of the safety device. For twohand
circuits this is 250mm, this distance can also be set to 0mm given an adequate cover on the buttons, however then S
must be at least 100mm.

The overtravel time for the entire system is 90ms. Then the above equation gives for the minimum distance:

S = (1600 mm/s · 0.09 s) + 250 mm
S = 144 mm + 250 mm = 394 mm

If a suitable cover is used, S can be reduced to 144mm (see above).

Note: The items listed under “Electrical connection” must be observed during commissioning.

1. Wiring ESM-2H2..:

Wire the ESM-2H2.. with the EUCHNER basic device
according to your application (see Fig. 1).

2. Wiring feedback loop:
Wire the feedback loop as shown in Fig. 2.

3. Wiring power supply:
Connect the power supply to terminals A1 and A2.

Warning: Wiring only in de-energized state.

4. Starting the device:

Switch the operating voltage on.

5. Switch to working condition:

Press the two buttons T1 and T2 simultaneously, or within

0.5 seconds.

The positive-guided relay switches.

6. Switch into hibernation:

Release the two buttons T1 and T2.

The positive-guided relay swiches off.

EUCHNER GmbH + Co. KG Kohlhammerstraße 16 D-70771 Leinfelden-Echterdingen Tel. [phone] Fax [phone] www.euchner.de [e-mail]

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