Schmersal ZT 235, ZT 236, ZT 255, ZT 256 Operating instructions

Operating instructions
Position switches

Operating instructions. . . . . . . . . . . . .pages 1 to 6

EN

Original

Z/T 235/236
Z/T 255/256

1. About this document

1.1 Function

This operating instructions manual provides all the information you
need for the mounting, set-up and commissioning to ensure the safe
operation and disassembly of the safety switchgear. The operating
instructions must be available in a legible condition and a complete
version in the vicinity of the device.

1.2 Target group: authorised qualified personnel

All operations described in this operating instructions manual must
be carried out by trained specialist personnel, authorised by the plant
operator only.

Please make sure that you have read and understood these operating
instructions and that you know all applicable legislations regarding
occupational safety and accident prevention prior to installation and
putting the component into operation.

The machine builder must carefully select the harmonised standards to
be complied with as well as other technical specifications for the selec­tion, mounting and integration of the components.

1.3 Explanation of the symbols used

Content

1 About this document

1.1 Function ..............................................1

1.2 Target group: authorised qualied personnel..................1

1.3 Explanation of the symbols used ...........................1

1.4 Appropriate use ........................................1

1.5 General safety instructions ...............................1

1.6 Warning about misuse ...................................1

1.7 Exclusion of liability .....................................2

2 Product description

2.1 Ordering code .........................................2

2.2 Special versions........................................2

2.3 Destination and use .....................................2

2.4 Technical data .........................................2

2.5 Safety classication .....................................2

3 Mounting

3.1 Dimensions ...........................................3

3.2 Mounting of the position switches ..........................3

3.3 Mounting of the actuating heads ...........................3

3.4 Actuation of the position switches ..........................4

4 Electrical connection

4.1 General information for electrical connection..................4

4.2 Contact variants........................................4

Information, hint, note:

This symbol is used for identifying useful additional information.

Caution: Failure to comply with this warning notice could
lead to failures or malfunctions.
Warning: Failure to comply with this warning notice could
lead to physical injury and/or damage to the machine.

1.4 Appropriate use

The products described in these operating instructions are developed to
execute safety-related functions as part of an entire plant or machine. It
is the responsibility of the manufacturer of a machine or plant to ensure
the correct functionality of the entire machine or plant.

The safety switchgear must be exclusively used in accordance with the
versions listed below or for the applications authorised by the manufac­turer. Detailed information regarding the range of applications can be
found in the chapter "Product description".

1.5 General safety instructions

The user must observe the safety instructions in this operating instruc­tions manual, the country-specific installation standards as well as all
prevailing safety regulations and accident prevention rules.

Further technical information can be found in the Schmersal
catalogues or in the online catalogue on the Internet:
www.schmersal.net.

The information contained in this operating instructions manual is pro­vided without liability and is subject to technical modifications.

There are no residual risks, provided that the safety instructions as well
as the instructions regarding mounting, commissioning, operation and
maintenance are observed.

1.6 Warning about misuse

x.000 / 03.2016 / v.A. - 101103624-EN / R / 2016-03-01 / AE-Nr. 5787

5 Set-up and maintenance

5.1 Functional testing.......................................4

5.2 Maintenance ..........................................4

6 Disassembly and disposal

6.1 Disassembly...........................................4

6.2 Disposal ..............................................4

7 EU Declaration of conformity

EN

In case of improper use or manipulation of the safety switch­gear, personal hazards or damages to machinery or plant
components cannot be excluded when safety switchgear is
used. The relevant requirements of the standard ISO 14119
must be observed.

1

Operating instructions

MT

Bdxxhs/h3600

Position switches

Z/T 235/236
Z/T 255/256

1.7 Exclusion of liability

We shall accept no liability for damages and malfunctions resulting from
defective mounting or failure to comply with this operating instructions
manual. The manufacturer shall accept no liability for damages result­ing from the use of unauthorised spare parts or accessories.

For safety reasons, invasive work on the device as well as arbitrary re­pairs, conversions and modifications to the device are strictly forbidden;
the manufacturer shall accept no liability for damages resulting from
such invasive work, arbitrary repairs, conversions and/or modifications
to the device.

2. Product description

2.1 Ordering code

This operating instructions manual applies to the following types:

➀➁2➂➃-➄Z➅-➆-➇-➈-➉

No. Option Description

Z Snap action

➀

T Slow action
Actuator selection, refer to catalogue

➁

3 Slim design

➂

5 Large design
5 Metal enclosure

➃

6 Thermoplastic enclosure
02 2 NC

➄

11 1 NO / 1 NC
20 2 NO (not suitable for safety applications)
H Slow action with staggered contacts

➅

UE Slow action with overlapping contacts

➆

Cable entry M20
ID Cut clamp terminals
NPT Cable entry NPT 1/2"
ST M12 connector (A coding)
2310 M12 connector (B coding)
1297 Enclosure with transverse slotted holes

➇

2138 Roller lever 7H for safety applications

➈

1637 Gold-plated contacts

➉

In accordance with the Machinery Directive, the type plate on
safety components is labelled as "Safety component".

Only if the information described in this operating instructions
manual are realised correctly, the safety function and therefore
the compliance with the Machinery Directive is maintained.

2.2 Special versions

For special versions, which are not listed in the order code below 2.1,
these specifications apply accordingly, provided that they correspond to
the standard version.

2.3 Destination and use

The position switches with safety function are suitable for sliding and
hinged guards, which need to be closed in order to ensure the required
operational safety.

A

A

The user must evaluate and design the safety chain in
accordance with the relevant standards and the required
safety level.

If multiple safety components are wired in series, the
Performance Level to ISO 13849-1 will be reduced due to
the restricted error detection under certain circumstances.

The entire concept of the control system, in which the safety
component is integrated, must be validated to the relevant
standards.

2.4 Technical data

Standards: IEC 60947-5-1, ISO 13849-1, BG-GS-ET-15
Design: EN 50047
Enclosure: 236, 256: glass-fibre reinforced thermoplastic,

self-extinguishing,

235: zinc die-cast, enamel finish,

255: aluminium die-cast, enamel finish

Protection class: IP67
Contact material: Silver
Contact type: change-over contact with double break, type Zb

or 1 NC or 2 NC contacts, with

galvanically separated contact bridges

Switching system:

A

IEC 60947-5-1, slow or snap action,

NC contacts with positive break

Connection: screw terminals
Cable section: min. 0.75 mm²; max. 2.5 mm²;

solid and stranded wire with conductor ferrules

Cable entry: 235, 236: 1 x M20 x 1.5;

255: 3 x M20 x 1.5;

256: 2 x M20 x 1.5

Ambient temperature: –30 °C … +80 °C
Mechanical life: 20 million operations
Max. switching frequency: 5000/h
Max. Actuating speed: 1 m/s
Bounce duration: slow action: < 3 ms;

snap action: in accordance with actuating speed

Switchover time: slow action: in accordance with actuating speed

Electrical data

Utilisation category: AC-15, DC-13
Ie/Ue: 4 A / 230 VAC; 1 A / 24 VDC
U

: 6 kV; connector: 0.8 kV

imp

Ui: 500 V; connector: 50 V
I

: 10 A

the

Max. fuse rating: 6 A gG D-fuse
Required short-circuit current: 1000 A

For NPT threads, conduit hub is to be connected
to conduit before hub is connected to enclosure.
For 256 Models: Not for use with rigid conduit.

2.5 Safety classification

Standards: ISO 13849-1
B

(NC contact): 20.000.000

10d

B

(NO contact) at 10% ohmic contact load: 1.000.000

10d

Service life: 20 years

2

TF

d

10d op op

0,1 x n

n

op

op

t

cycle

(Specifications can vary depending on the application-specific
parameters hop, dop and t

as well as the load.)

cycle

EN