Release 07/2010 Ver. 2.3

Installation Instructions: PRSU/4

PRSU/4 Safety Interface Controller
Installation Instructions
START INTERLOCK - When power is applied to the system,
the output relays cannot be energized until a reset signal has
been applied.

1. INTRODUCTION
Tapeswitch PRSU/4 control units are designed to be used withTapeswitch pressure sensitive sensors to form a complete safetysystem. Sensors may take the form of safety mats, sensing
edges, ribbon switches or bumpers. Full system installation
instructions are supplied with the sensors.

RESTART INTERLOCK - Once the sensor has been actuatedand the output relays have de-energized, they cannot beenergized again until a reset signal has been applied.
In auto reset mode the output relays will be energized whenever
power is applied to the system and the sensor is clear.

2. PRODUCT DESCRIPTION
The unit operates from a 24VAC/DC supply. From this isderived a current-limited 24VDCsupply. The sensor and control
circuit operate from this current-limited supply. The unit ishoused in a DIN rail mounting enclosure with 12 integral
terminals. This unit is intended to be mounted in an existing
electrical enclosure on the machine. This existing enclosuremust be sealed to a minimum rating of IP54.

In manual or auto reset mode, reset will be prevented if thesensor is actuated, if there is a fault in the reset input circuit, orif the two output relays are in disparity.
The safety output contacts of the control unit are connected tothe machine primary control element(s) in such a way that ifeither of the safety output relays is de-energized then themachine will be brought to rest regardless of the state of theother relay.

3. SAFETY INTEGRITY
Tapeswitch PRSU/4 control units exceed the requirements ofsafety integrity level 3 as defined by EN 954-1. The control
units are self-monitoring, which means that any faults in safety
critical components will be detected and will render the machine
inoperative until the fault is rectified.

NOTE: A machine primary control element or MPCE is definedas „an electrically controlled element which directly controls thenormal operating motion of a machine such that it is the last (intime) to operate when motion is initiated or arrested‟.

However, the safety integrity of the system as a whole depends
on the safety integrity of the sensor used. See information
supplied with sensor for further details.

In addition, where the machine control system has two MPCEs,
these devices can be monitored by connecting normally-closed
auxiliary contacts from each MPCE in series with the reset
input. Disparity between the two MPCEs will prevent a reset.

4. PRINCIPLE OF OPERATION

5. MONITOR OUTPUT

The control unit contains the power supply for the system, thesafety output relays and the reset circuit. Figure 1 shows theprinciple of operation. A 24VDC power supply is taken fromthe control unit to the switching elements in the sensor(s), +ve
to one conductor, -ve to the other conductor, and back to thecontrol unit where it supplies power to the output relays. The
output contacts of the safety relays are only closed when theoutput relays are energized. When the sensor is actuated, the 24
VDC power supply to the output relays is shorted out causing
them to de-energize. Furthermore, if the power supply to theoutput relays is interrupted or shorted out by a fault in thesensor wiring or in the switch elements, power to the output
relays will be lost, the relays will de-energize and the output
contacts will open.

The monitor output is a changeover volt-free relay output. The
monitor relay is energized when the safety output relays areenergized. The monitor output can be used as an input to amachine control device such as a programmable logic controller(PLC) to signal that the sensor has been actuated.
NOTE: The monitor output is not a safety output andmust not be used in the machine stop circuit.

The unit provides a manual or auto reset function.
In manual reset mode the reset function provides start andrestart interlock functions as follows:
Figure 1- Principle of Operation
TAPESWITCH CORPORATION
100 Schmitt Boulevard
Farmingdale, New York 11735

1

Phone: 631-630-0442
Fax: 631-630-0454
www.tapeswitch.com

Release 07/2010 Ver. 2.3

Installation Instructions: PRSU/4

6.2 ELECTRICAL

6. INSTALLATION

6.2.1 GENERALWARNING

The connections for the PRSU/4 control unit are shown inFigure 3. Crimped ferrules should be fitted on all strandedwires. It is recommended that the electrical installation beperformed in the order described below.

TAPESWITCH SAFETY SYSTEMS ARE DESIGNED TO
PROTECT OPERATORS WORKING AT OR NEARDANGEROUS MACHINES. THEY CAN ONLY PERFORM
THAT FUNCTION IF THEY ARE CORRECTLY FITTEDAND INTERFACED TO A SUITABLE MACHINE. EVERYEFFORT HAS BEEN MADE TO PROVIDE ACCURATE
AND COMPREHENSIVE INFORMATION, BUT IT IS THERESPONSIBILITY OF THE USER TO ENSURE THAT ALLPERSONS INVOLVED IN THE INSTALLATION OF THE
PRODUCT HAVE THE KNOWLEDGE, TRAINING AND
EXPERIENCE NECESSARY, AND THAT THEY AREFULLY CONVERSANT WITH ALL LAWS, RULES,REGULATIONS AND CODES OF PRACTICE PERTAINING
TO THEIR TASK.

6.2.2 SENSOR CONNECTION
Connect the sensor cables to the control unit according to Table
1 and the diagrams in Appendix A, taking particular care that
there are no stray strands which could cause a short between
adjacent terminals.
When a number of sensors are used in combination, they should
be connected in series such that the control unit “sees” a single
normally-open switch, as shown in Figure 4.

6.1 MECHANICAL

6.2.3 POWER CONNECTION

6.1.1 GENERALConnect +24V to terminal A1 and +0V to terminal A2 as shownin Figure 3. The maximum power consumption is 5VA.

The PRSU/4 control units should be mounted in the machine
control unit on standard „top hat‟ terminal rail type DIN EN 50
022-35. The machine control unit must provide sealing to IP54
according to IEC 529. The dimensions of the unit are shown inFigure 2.

6.2.4 RESET INPUT CONNECTION
For auto reset mode connect a link across terminals S33 & S34as shown in Figure 5.
For manual reset mode connect a normally open switch acrossterminals S33 & S34 as shown in Figure 6.

The exact cabling requirements are at the discretion of theinstaller and depend to a large extent on the siting of the various
control system elements. Generally it is recommended that highvoltage cables are routed away from low voltage cables.

If the machine has two MPCEs, a pair of normally closed
auxiliary contacts from each MPCE can be connected in series
with the reset input as shown in Figure 7. This provides crossmonitoring of the MPCEs such that, if they are in disparity due
to a fault, reset will be prevented until the fault is rectified.

6.1.2. RESET INPUT DEVICE
A momentary action, normally open switch, preferably a 22mm
industrial pushbutton, should be used to provide the reset input.
The switch should be housed in a suitable enclosure and should
be mounted in such a position that it is safe from damage by
passing traffic and such that the person operating the switch cansee all of the dangerous area.

6.2.5 SAFETY OUTPUT CONNECTION
Two normally-open safety outputs are provided. In low-tomedium risk applications, the machine may be provided with asingle MPCE. In such a case, both safety outputs should beconnected in series with the MPCE coil as shown in Figure 8.
If the machine is fitted with two MPCEs, one safety output
should be connected in series with each MPCE coil as shown inFigure 9.
To protect the contacts of the safety output relays from theeffects of switching inductive loads, it is recommended that arc
suppressors be installed in parallel with the MPCE coils asshown Figures 8 and 9. Arc suppressors must not be installed
across the safety relay contacts.

Figure 2

To protect against the possibility the safety output contacts
welding together due to an overcurrent fault in the machine
circuit, 2A fuses should be installed in series with the MPCE
coils as shown in Figures 8 and 9. This limits the current
through the safety output contacts to well below that which
could cause them to weld.

TAPESWITCH CORPORATION
100 Schmitt Boulevard
Farmingdale, New York 11735

2

Phone: 631-630-0442
Fax: 631-630-0454
www.tapeswitch.com

Release 07/2010 Ver. 2.3

Installation Instructions: PRSU/4

Figure 3 – Pinouts

Figure 5 – Auto Reset

Table 1Figure 6 – Manual Reset

Figure 7– Cross-Monitoring of MPCEs
Figure 4 – Sensors in Series

TAPESWITCH CORPORATION
100 Schmitt Boulevard
Farmingdale, New York 11735

3Phone: 631-630-0442
Fax: 631-630-0454
www.tapeswitch.com

Release 07/2010 Ver. 2.3

Installation Instructions: PRSU/4

7. TECHNICAL SPECIFICATION
Safety GradeType 3 (EN 954-1)

Power Consumption

5 VA

Response Time< 30 ms

Temperature Range:
Operating-25 ºC to +55 ºC

Reset Function

Manual or Auto (Link Selectable)

Supply Voltage

24 Vac/dc

Safety Outputs:
Device Type

Figure 8 – Safety output connection (single MPCE)

Contact Rating

Safety Relay,
Force-guided Contacts
3 x Normally Open
1 x Normally Closed (Monitor)
5 A @ 230 Vac

Enclosure:Protection rating
Terminal Capacity
Material

IP 20
2 x 1.5 mm²
Polycarbonate

Contact Type/Quantity

Table 3Figure 9 – Safety output connections (two MPCEs)

6.3 INITIAL CHECKING
The system can be checked at this point as follows:(a) Check that the sensor is clear.
(b) Apply power to the control unit. DO NOT APPLY POWER
TO THE MPCEs. The POWER ON indicator should be lit, theCHANNEL 1 and CHANNEL 2 indicators should be off.
(c) Activate the reset button. The CHANNEL 1 and CHANNEL
2 indicators should illuminate.
(d ) Actuate the sensor. The CHANNEL 1 and CHANNEL 2indicators should go off.
If the system operates as described above the installation can becompleted. Before putting the machine into use the complete
system should be commissioned as described in the sensor
manual. If the safety system does not operate as described aboverefer to the sensor manual for fault finding procedure.

TAPESWITCH CORPORATION
100 Schmitt Boulevard
Farmingdale, New York 11735

4Phone: 631-630-0442
Fax: 631-630-0454
www.tapeswitch.com

Release 07/2010 Ver. 2.3

Installation Instructions: PRSU/4

APPENDIX A
INTERCONNECT DIAGRAMS, DAISY CHAINED/SERIES CONNECTION
Multiple Mats with 4 Conductor Standard Color Coded Lead Wire

MAT 1

S11A
S21B
S12C
S22D

MAT 2

MAT 3

MAT N

BLACK

YELLOWBLACK

YELLOWBLACKYELLOW

BLACKRED

WHITERED

WHITERED

WHITEREDYELLOW
WHITE

Multiple Mats with Optional 2 Conductor Standard Color Coded Lead Wire

MAT 1

S11A
S21B
S12C
S22DMAT 2

MAT 3

MAT N

BLACK

BLACK

BLACK

BLACK

BLACK

BLACK

BLACK

WHITE

WHITE

WHITE

WHITE

WHITE

WHITE

WHITE

BLACK
WHITE

Multiple Sensing Edges, Bumpers and Ribbon Switches with Color Coded Wire

A
S11B
S21
S12C
S22
D

BLACK

BLK

BLK

Edge/sensor 1
WHITE
BLACK

BLK

BLK

Edge/sensor 2
WHT

WHT

WHITE
Edge/sensor N

WHT

WHT

BLACK

WHITE
Multiple Sensing Edges, Bumpers and Ribbon Switches with Non-Color Coded Zip Cord Wire

A
S11B
S21
S12C
S22DRIBBED

RIB

RIB

SMO

SMO

Edge/sensor 1
SMOOTHRIBBED

RIB

RIB

SMO

SMO

Edge/sensor 2

SMOOTH
Edge/sensor N
RIBBEDSMOOTHTAPESWITCH CORPORATION
100 Schmitt Boulevard
Farmingdale, New York 11735

5

Phone: 631-630-0442
Fax: 631-630-0454
www.tapeswitch.com