Pilz PST 4 User manual

PST 4
Operating Manual-18436-EN-09
-Safety relays

Preface
This document is the original document.
Where unavoidable, for reasons of readability, the masculine form has been selected when
formulating this document. We do assure you that all persons are regarded without discrim-
ination and on an equal basis.
All rights to this documentation are reserved by Pilz GmbH & Co. KG. Copies may be made
for the user's internal purposes. Suggestions and comments for improving this documenta-
tion will be gratefully received.
Pilz®, PIT®, PMI®, PNOZ®, Primo®, PSEN®, PSS®, PVIS®, SafetyBUS p®,
SafetyEYE®, SafetyNET p®, the spirit of safety® are registered and protected trademarks
of Pilz GmbH & Co. KG in some countries.
SD means Secure Digital

Contents
Operating Manual PST 4
18436-EN-09 | 3
Introduction ............................................................................................................................4
Validity of documentation ..........................................................................................................4
Using the documentation ..........................................................................................................4
Definition of symbols .................................................................................................................4
Safety ......................................................................................................................................5
Intended use .............................................................................................................................5
Safety regulations .....................................................................................................................5
Safety assessment....................................................................................................................5
Use of qualified personnel.........................................................................................................6
Warranty and liability.................................................................................................................6
Disposal ....................................................................................................................................6
For your safety ..........................................................................................................................6
Unit features ...........................................................................................................................7
Safety features .......................................................................................................................7
Block diagram/terminal configuration .................................................................................7
Function Description .............................................................................................................8
Operating modes.......................................................................................................................8
Timing diagram .........................................................................................................................9
Installation ..............................................................................................................................9
Wiring ......................................................................................................................................10
Preparing for operation .........................................................................................................11
Operation ................................................................................................................................13
Status indicators........................................................................................................................13
Faults – Interference ..............................................................................................................13
Dimensions in mm .................................................................................................................14
Technical details ....................................................................................................................15
Safety characteristic data..........................................................................................................19
Supplementary data ...............................................................................................................20
Service life graph ......................................................................................................................20
Order reference ......................................................................................................................21
EC declaration of conformity ................................................................................................21
UKCA-Declaration of Conformity .........................................................................................21

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18436-EN-09 | 4
Introduction
Validity of documentation
This documentation is valid for the product PST 4. It is valid until new documentation is
published.
This operating manual explains the function and operation, describes the installation and
provides guidelines on how to connect the product.
Using the documentation
This document is intended for instruction. Only install and commission the product if you
have read and understood this document. The document should be retained for future ref-
erence.
Definition of symbols
Information that is particularly important is identified as follows:
DANGER!
This warning must be heeded! It warns of a hazardous situation that poses
an immediate threat of serious injury and death and indicates preventive
measures that can be taken.
WARNING!
This warning must be heeded! It warns of a hazardous situation that could
lead to serious injury and death and indicates preventive measures that can
be taken.
CAUTION!
This refers to a hazard that can lead to a less serious or minor injury plus
material damage, and also provides information on preventive measures
that can be taken.
NOTICE
This describes a situation in which the product or devices could be dam-
aged and also provides information on preventive measures that can be
taken. It also highlights areas within the text that are of particular import-
ance.

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Operating Manual PST 4
18436-EN-09 | 5
INFORMATION
This gives advice on applications and provides information on special fea-
tures.
Safety
Intended use
The safety relay PST 4 provides a safety-related interruption of a safety circuit.
The safety relay meets the requirements of EN 60947-5-1 and EN 60204-1 and may be
used in applications with:
}Safety gates
Improper use
The following is deemed improper use in particular:
}Any component, technical or electrical modification to the product,
}Use of the product outside the areas described in this operating manual,
}Use of the product outside the technical details (see chapter entitled Technical
Details [ 15]).
NOTICE
EMC-compliant electrical installation
The product is designed for use in an industrial environment. The product
may cause interference if installed in other environments. If installed in other
environments, measures should be taken to comply with the applicable
standards and directives for the respective installation site with regard to in-
terference.
Safety regulations
Safety assessment
Before using a device, a safety assessment in accordance with the Machinery Directive is
required.
The product as an individual component fulfils the functional safety requirements in accord-
ance with EN ISO 13849 and ENIEC62061. However, this does not guarantee the func-
tional safety of the overall plant/machine. To achieve the relevant safety level of the overall
plant/machine’s required safety functions, each safety function needs to be considered sep-
arately.

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Operating Manual PST 4
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Use of qualified personnel
The products may only be assembled, installed, programmed, commissioned, operated,
maintained and decommissioned by persons who are competent to do so.
A competent person is a qualified and knowledgeable person who, because of their train-
ing, experience and current professional activity, has the specialist knowledge required. To
be able to inspect, assess and operate devices, systems and machines, the person has to
be informed of the state of the art and the applicable national, European and international
laws, directives and standards.
It is the company’s responsibility only to employ personnel who
}Are familiar with the basic regulations concerning health and safety / accident prevention,
}Have read and understood the information provided in the section entitled Safety
}Have a good knowledge of the generic and specialist standards applicable to the specific
application.
Warranty and liability
All claims to warranty and liability will be rendered invalid if
}The product was used contrary to the purpose for which it is intended,
}Damage can be attributed to not having followed the guidelines in the manual,
}Operating personnel are not suitably qualified,
}Any type of modification has been made (e.g. exchanging components on the PCB
boards, soldering work etc.).
Disposal
}In safety-related applications, please comply with the mission time TM in the safety-related
characteristic data.
}When decommissioning, please comply with local regulations regarding the disposal of
electronic devices (e.g. Electrical and Electronic Equipment Act).
For your safety
The unit meets all the necessary conditions for safe operation. However, please note the
following:
}Note for overvoltage category III: If voltages higher than low voltage (>50 VAC or >120
VDC) are present on the unit, connected control elements and sensors must have a rated
insulation voltage of at least 250 V.

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Unit features
}Positive-guided relay outputs:
– 6 safety contacts (N/O), instantaneous
– 4 auxiliary contacts (N/C), instantaneous
}Connection options for:
– Safety gate limit switches
– Start button
}LED indicator for:
– Supply voltage
– Input state channel 1/2
– Output state channel 1/2
}See order reference for unit types
Safety features
The safety relay meets the following safety requirements:
}The circuit is redundant with built-in self-monitoring.
}The safety function remains effective in the case of a component failure.
}The correct opening and closing of the safety function relays is tested automatically in
each on-off cycle.
Block diagram/terminal configuration
S23 S24S12S11
S33 S34Y2Y1
13 23 33 43
14 24 34 44
53 63
54 64
71
72
81
82
91
92
01
02
PST 4
S11 S12 S13 S24 S33 S34 Y1 Y2
A1 13 23 33 43 53 63 71 81 91 01
CH.1 IN
POWER
CH.2 IN
CH.1 OUT
CH.2 OUT
14 24 34 44 54 64 72 82 92 02 A2
*Insulation between the non-marked area and the relay contacts: Basic insulation (over-
voltage category III), Protective separation (overvoltage category II)

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Operating Manual PST 4
18436-EN-09 | 8
Function Description
The safety gate monitor PST 4 provides a safety-oriented interruption of a safety circuit.
When operating voltage is supplied the "POWER" LED will light. The unit is ready for oper-
ation when the feedback loop Y1-Y2 and the start circuit S33-S34 are closed.
}Input circuit closed within the simultaneity period (safety gate closed)
– The LEDs "CH.1 IN", "CH.2 IN" and "CH.1 OUT" and "CH.2 OUT" are lit
– Safety contacts 13-14, 23-24, 33-34, 43-44, 53-54 and 63-64 are closed, auxiliary
contacts 71-72, 81-82, 91-92 and 01-02 are opened. The unit is active.
}Input circuit is opened (safety gate opened)
– The LEDs "CH.1IN" and "CH.2 IN" go out.
– Safety contacts 13-14, 23-24, 33-34, 43-44, 53-54 and 63-64 are opened redund-
antly, auxiliary contacts 71-72, 81-82, 91-92 and 01-02 are closed.
– The LEDs "CH.1 OUT" and "CH.2 OUT" go out.
If the input circuits have already switched before supply voltage is applied, the PST 4 stops
the plant being enabled, to prevent an automatic start-up in accordance with
EN60204Pt7.5.
Reset function
The safety contacts and auxiliary contacts remain in rest condition (safety contacts are
open and auxiliary contacts are closed) if the supply voltage is applied when the safety gate
is closed. The safety and auxiliary contacts are not activated until the safety gate has been
opened and then closed again. N/C contacts in series with the safety gate limit switches S1
and S2 can simulate the opening of the safety gate.
Operating modes
}Dual-channel operation with detection of shorts across contacts: Redundant input circuit,
PST 4 detects
– earth faults in the start and input circuit,
– short circuits in the input circuit,
– shorts across contacts in the input circuit.
}Automatic start: Unit is active once the input circuit has been closed.
}Manual start: Unit is active once the input circuit and the start circuit are closed.
}Increase in the number of available contacts by connecting contact expandsion modules
or external contactors/relays.

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Timing diagram
[1] [2]
Legend
}Power: Supply voltage
}Start: Start circuit
}Input: Input circuits
}Output safe: Safety contacts
}[1]: Automatic start
}[2]: Manual start
}a: Input circuit closes before start circuit
}b: Start circuit closes before input circuit
}t1: Switch-on delay
}t2: Delay-on de-energisation
}t3: Recovery time
Installation
}The unit should be installed in a control cabinet with a protection type of at least IP54.
}Use the notch on the rear of the unit to attach it to a DIN rail (35 mm).
}When installed vertically: Secure the unit by using a fixing element (e.g. retaining bracket
or end angle).

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Wiring
Please note:
}Information given in the "Technical details [ 15]" must be followed.
}Outputs 13-14, 23-24, 33-34, 43-44, 53-54, 63-64 are safety contacts; outputs 71-72,
81-82, 91-92, 01-02 are auxiliary contacts (e.g. for display).
}Do not use auxiliary contacts 71-72, 81-82, 91-92, 01-02 for safety circuits!
}Do not connect undesignated terminals.
}To prevent contact welding, a fuse should be connected before the output contacts (see
Technical details [ 15]).
}Calculation of the max. cable length lmax in the input circuit:
Rlmax
Rl / km
Imax =
Rlmax = max. overall cable resistance (see Technical details [ 15])
Rl/km = cable resistance/km
}Use copper wiring with a temperature stability of 60/75 °C.
}To prevent EMC interferences (particularly common-mode interferences) the measures
described in EN60204-1 must be executed. This includes the separate routing of cables
of the control circuits (input, start and feedback loop) from other cables for energy trans-
mission or the shielding of cables, for example.
}Adequate protection must be provided on all output contacts with capacitive and inductive
loads.
}Do not switch low currents using contacts that have been used previously with high cur-
rents.
}On 24 VDC devices:
The power supply must comply with the regulations for extra low voltages with protective
electrical separation (SELV, PELV) in accordance with VDE 0100, Part 410.

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Preparing for operation
Supply voltage AC DC
A1
A2
L1
N
FE
A1
A2
L+
L-
Input circuit Dual-channel Dual-channel with reset function
Safety gate
with detection of shorts across
contacts
S11 S1 S2
S12
S23
S24
S11 S1
S3
S2
S12
S23
S24
Start circuit Automatic start Manual start
S33
S34
S3
NOTICE
In the event of an automatic start or manual start with bridged start
contact (fault):
The unit starts up automatically when the safeguard is reset, e.g. when the
E-STOP pushbutton is released. Use external circuit measures to prevent
an unexpected restart.

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Feedback loop Without feedback loop monitor-
ing
With feedback loop monitoring
Link or contacts from external con-
tactors
Y1
13 (23 ... 63)
14 (24 ... 64)
K3 K4
K3
K4
N
L1
Y2
Start-up testing
Y1
Y2
INFORMATION
The feedback circuit must be closed at least 500 ms before limit switch S1
is operated and may only be opened once limit switch S1 has been oper-
ated.
Legend
}S1/S2: Safety gate switch
}S3: Start button
}: Switch operated
}: Gate open
}: Gate closed

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Operation
When the relay outputs are switched on, the mechanical contact on the relay cannot be
tested automatically. Depending on the operational environment, measures to detect the
non-opening of switching elements may be required under some circumstances.
When the product is used in accordance with the European Machinery Directive, a check
must be carried out to ensure that the safety contacts on the relay outputs open correctly.
Open the safety contacts (switch off output) and start the device again, so that the internal
diagnostics can check that the safety contacts open correctly
}for SIL 3/PL e at least 1x per month
}for SIL 2/PL d at least 1x per year
NOTICE
The safety functions should be checked after initial commissioning and each
time the plant/machine is changed. The safety functions may only be
checked by qualified personnel.
Status indicators
LEDs indicate the status and errors during operation:
LED on
POWER
Supply voltage is present.
CH.1 IN
Channel 1 input circuit is closed.
CH.2 IN
Channel 2 input circuit is closed.
CH.1 OUT
Channel 1 safety contacts are closed.
CH.2 OUT
Channel 2 safety contacts are closed.
Faults – Interference
}Earth fault: The supply voltage fails and the safety contacts open. Once the cause of the
respective fault has been rectified and the supply voltage is switched off for approx.
1minute, the unit is ready for operation again.
}Contact malfunctions: If the contacts have welded, reactivation will not be possible after
the input circuit has opened.
}LED "POWER" does not light: Short circuit or no supply voltage.
}CH.1 OUT and CH.2 OUT do not light:
Only one limit switch is closed. Simultaneity was not maintained.

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Dimensions in mm

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Technical details
General
Certifications CCC, CE, EAC, TÜV, UKCA, cULus Listed
Electrical data
Supply voltage
Voltage 24 V
Kind DC
Voltage tolerance -15 %/+10 %
Output of external power supply (DC) 5,5 W
Residual ripple DC 20 %
Duty cycle 100 %
Max. inrush current impulse
Current pulse, A1 10 A
Pulse duration, A1 0,5 ms
Inputs
Quantity 2
Voltage at
Input circuit DC 24 V
Start circuit DC 24 V
Feedback loop DC 24 V
Current at
Input circuit DC 30 mA
Start circuit DC 30 mA
Feedback loop DC 30 mA
Max. overall cable resistance Rlmax
Dual-channel with detection of shorts across con-
tacts at UB DC 100 Ohm
Relay outputs
Number of output contacts
Safety contacts (N/O), instantaneous 6
Auxiliary contacts (N/C) 4
Max. short circuit current IK 1 kA
Utilisation category
in accordance with the standard EN 60947-4-1

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Relay outputs
Utilisation category of safety contacts
AC1 at 400 V
Min. current 0,01 A
Max. current 5 A
Max. power 2000 VA
AC1 at 240 V
Min. current 0,01 A
Max. current 8 A
Max. power 2000 VA
DC1 at 24 V
Min. current 0,01 A
Max. current 8 A
Max. power 200 W
Utilisation category of auxiliary contacts
AC1 at 240 V
Min. current 0,01 A
Max. current 8 A
Max. power 2000 VA
DC1 at 24 V
Min. current 0,01 A
Max. current 8 A
Max. power 200 W
Utilisation category
in accordance with the standard EN 60947-5-1
Utilisation category of safety contacts
AC15 at 230 V
Max. current 5 A
DC13 (6 cycles/min) at 24 V
Max. current 7 A
Utilisation category of auxiliary contacts
AC15 at 230 V
Max. current 5 A
DC13 (6 cycles/min) at 24 V
Max. current 7 A
Utilisation category in accordance with UL
Voltage 240 V AC G. P.
with current 8 A
Voltage 24 V DC Resistive
with current 5 A
Pilot Duty B300, R300

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Relay outputs
External contact fuse protection, safety contacts
in accordance with the standard EN 60947-5-1
Max. melting integral 240 A²s
Blow-out fuse, quick 10 A
Blow-out fuse, slow 6 A
Blow-out fuse, gG 10 A
Circuit breaker 24V AC/DC, characteristic B/C 6 A
External contact fuse protection, auxiliary contacts
Max. melting integral 240 A²s
Blow-out fuse, quick 10 A
Blow-out fuse, slow 6 A
Blow-out fuse, gG 10 A
Circuit breaker, 24 VAC/DC, characteristic B/C 6 A
Contact material AgSnO2 + 0,2 µm Au
Conventional thermal current while loading sev-
eral contacts
Ith per contact at UB AC; AC1:240V,DC1:24V
Conv. therm. current with 1 contact 8 A
Conv. therm. current with 2 contacts 7 A
Conv. therm. current with 3 contacts 5,7 A
Conv. therm. current with 4 contacts 5 A
Conv. therm. current with 5 contacts 4,4 A
Conv. therm. current with 6 contacts 4 A
Ith per contact at UB DC; AC1:240V,DC1:24V
Conv. therm. current with 1 contact 8 A
Conv. therm. current with 2 contacts 7 A
Conv. therm. current with 3 contacts 5,7 A
Conv. therm. current with 4 contacts 5 A
Conv. therm. current with 5 contacts 4,4 A
Conv. therm. current with 6 contacts 4 A
Times
Switch-on delay
Typ. switch-on delay 100 ms
Delay-on de-energisation
with E-STOP typ. 30 ms
with E-STOP max. 50 ms
Supply interruption before de-energisation 10 ms
Simultaneity, channel 1 and 2 max. 4 s
Environmental data
Climatic suitability EN 60068-2-78
Ambient temperature
Temperature range -10 - 55 °C
Storage temperature
Temperature range -40 - 85 °C

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Environmental data
Climatic suitability
Humidity 93 % r. h. at 40 °C
Condensation during operation Not permitted
EMC EN 60947-5-1, EN 61000-6-2, EN 61326-3-1
Vibration
in accordance with the standard EN 60068-2-6
Frequency 10 - 55 Hz
Amplitude 0,35 mm
Airgap creepage
in accordance with the standard EN 60947-1
Overvoltage category III / II
Pollution degree 2
Rated insulation voltage 400 V
Rated impulse withstand voltage 4 kV
Protection type
Housing IP40
Terminals IP20
Mounting area (e.g. control cabinet) IP54
Mechanical data
Mounting position Any
Mechanical life 10,000,000 cycles
Material
Bottom PPO UL 94 V1
Front PMMA
Top PPO UL 94 V1
Connection type Screw terminal
Mounting type Fixed
Conductor cross section with screw terminals
1 core flexible 0,2 - 4 mm², 24 - 10 AWG
2 core with the same cross section, flexible with
crimp connectors, no plastic sleeve 0,2 - 2,5 mm², 24 - 14 AWG
2 core with the same cross section, flexible without
crimp connectors or with TWIN crimp connectors 0,2 - 2,5 mm², 24 - 14 AWG
Torque setting with screw terminals 0,5 Nm
Stripping length with screw terminals 6 mm
Dimensions
Height 87 mm
Width 90 mm
Depth 121 mm
Weight 530 g
Where standards are undated, the 2022-09 latest editions shall apply.

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Safety characteristic data
NOTICE
You must comply with the safety characteristic data in order to achieve the
required safety level for your plant/machine.
Operating
mode
EN ISO
13849-1:
2015
PL
EN ISO
13849-1:
2015
Category
EN IEC
62061
SIL CL/
maximum
SIL
EN IEC
62061
PFHD [1/h]
EN/IEC
61511
SIL
EN/IEC
61511
PFD
EN ISO
13849-1:
2015
TM [year]
–PL e Cat. 4 SIL 3 5,14E-09 SIL 3 4,98E-06 20
Explanatory notes for the safety-related characteristic data:
}Safety characteristic data in accordance with EN IEC 62061 and EN/IEC 61511 was cal-
culated based on EN/IEC 61508.
}TM is the maximum mission time in accordance with EN ISO 13849-1. The value also ap-
plies as the retest interval in accordance with EN/IEC 61508-6 and EN/IEC 61511 and as
the proof test interval and mission time in accordance with EN IEC 62061.
All the units used within a safety function must be considered when calculating the safety
characteristic data.
INFORMATION
A safety function's SIL/PL values are not identical to the SIL/PL values of
the units that are used and may be different. We recommend that you use
the PAScal software tool to calculate the safety function's SIL/PL values.

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Supplementary data
CAUTION!
It is essential to consider the relay's service life graphs. The relay outputs'
safety-related characteristic data is only valid if the values in the service life
graphs are met.
The PFH value depends on the switch frequency and the load of the relay output.
If the service life graphs are not accessible, the stated PFH value can be used irrespective
of the switch frequency and the load, as the PFH value already considers the relay's B10d
value as well as the failure rates of the other components.
Service life graph
The service life graphs indicate the number of cycles from which failures due to wear must
be expected. The wear is mainly caused by the electrical load; the mechanical load is negli-
gible.
Cycles x 1000
Switching current (A)
Example
}Inductive load: 0.2 A
}Utilisation category: AC15
}Contact service life: 4 000 000 cycles
Provided the application to be implemented requires fewer than 4 000 000 cycles, the PFH
value (see Technical details) can be used in the calculation.
To increase the service life, sufficient spark suppression must be provided on all output
contacts. With capacitive loads, any power surges that occur must be noted. With DC con-
tactors, use flywheel diodes for spark suppression.