TAPESWITCH CONTROL UNIT TYPEPSSR/2 INSTALLATION INSTRUCTIONS	  1. INTRODUCTIONTapeswitch PSSR/2 control units are designed tobe used with Tapeswitch pressure sensitivesensors to form a complete safety system. Thecontrol unit can be configured to monitor one or twosensors. Sensors may take the form of safety mats,sensing edges, ribbon switches or bumpers. Fullsystem installation instructions are supplied withthe sensors.
2. PRODUCT DESCRIPTIONThe unit operates from a 24 VAC/DC supply. Fromthis is derived a current limited 24 VDC supply. Thesensor and control circuit operate from this currentlimited supply. The unit is housed in a DIN railmounting enclosure with 14 integral terminals. Thisunit is intended to be mounted in an existingelectrical enclosure on the machine. This existingenclosure must be sealed to minimum rating ofIP54.

energized and the output contacts will open. Theunit provides a manual or auto reset functionselectable using internal switch SW2. In manualreset mode the reset function provides start andrestart functions as follows:START FUNCTION - When power is applied to thesystem, the output relays cannot be energizeduntil a reset signal has been applied.
RESTART FUNCTION - Once the sensor has beenactuated and the output relays have de-energized,they cannot be energized again until a reset signalhas been applied.
In auto reset mode the output relays will beenergized whenever power is applied to the systemand the sensor is clear.

3. SAFETY INTEGRITYTapeswitch PSSR/2 control units meet therequirements of Performance Level PLd as definedin EN13849-1:2008. The control units are selfmonitoring which means that any faults in safetycritical components will be detected and will renderthe machine inoperative until the fault is rectified.
However, the safety integrity of the system as awhole depends on the safety integrity of the sensorused. See information supplied with sensor forfurther details.
4. PRINCIPLE OF OPERATIONThe control unit contains the power supply for thesystem, the safety output relays and the resetcircuit. Figure 1 shows the principle of operation.
The sensor(s) incorporates an end-of-line resistorand the output relays are only energized when thisresistance is detected the output contacts of thesafety relays are only closed when the outputrelays are energized. When the sensor is actuated,the end-of-line resistor is short-circuited thischanged in resistance is detected by the controlunit causing the output relays to de-energized.
Furthermore, if the power supply to the control unitis interrupted or there is a fault in the sensor wiringor in the switch elements, the relays will de-	  1	   	  	  Figure 1 - Principle of Operation6. INSTALLATIONWARNINGTAPESWITCHSAFETYSYSTEMSAREDESIGNEDTOPROTECTOPERATORSWORKINGATORNEARDANGEROUSMACHINES. THEY CAN ONLY PERFORM THATFUNCTION IF THEY ARE CORRECTLY FITTEDAND INTERFACED TO A SUITABLE MACHINE.
EVERY EFFORT HAS BEEN MADE TOPROVIDE COMPREHENSIVE AND ACCURATEINFORMATION. IT IS THE RESPONSIBILITY OFTHE USER TO ENSURE THAT ALL PERSONSINVOLVED IN THE INSTALLATION OF THEPRODUCT HAVE THE KNOWLEDGE, TRAININGAND EXPERIENCE NECESSARY AND THATTHEY ARE FULLY CONVERSANT WITH ALLLAWS, RULES, REGULATIONS AND CODES OFPRACTICE PERTAINING TO THEIR TASK.

www.tapeswitch.com	  	  	  6.1 MECHANICAL6.1.1 GENERALThe PSSR/2 control units should be mounted in themachine control unit on standard ‘top hat’ terminalrail type DIN EN 50 022-35. The machine controlunit must provide sealing to IP54 according to IEC529. The dimensions of the unit are shown inFigure 2. The exact cabling requirements are at thediscretion of the installer and depend to a largeextent on the siting of the various control systemelements. Generally, it is recommended that highvoltage cables are routed away from low voltagecables.
6.1.2. RESET SWITCHA momentary action, normally-open switch,preferably a 22 mm industrial pushbutton, shouldbe used to provide the reset input. The switchshould be housed in a suitable enclosure andshould be mounted in such a position that it is safefrom damage by passing traffic and such that theperson operating the switch can see all of thedangerous area.

gently pry upwards the central lid Connect thesensor cables to the control unit according to Table1, taking particular care that there are no straystrands, which could cause a short betweenadjacent terminals.
6.2.3 RESET INPUT CONNECTIONFor auto reset mode set internal switch SW2, asshown in Figure 5, and connect a link acrossterminals X1 and X2, as shown in Figure 6. Formanual reset mode set internal switch SW2, asshown in Figure 5, and connect a normally-openswitch across terminals X1 and X2 as shown inFigure 7.
If the machine has two MPCEs, a pair of normallyclosed auxiliary contacts from each MPCE can beconnected in series with the reset input as shown inFigure 8. This provides cross monitoring of theMPCEs such that if they are in disparity due to afault, reset will be prevented until the fault isrectified.
6.2.4 POWER CONNECTIONConnect +24 V to terminal A1 and 0V to terminalA2 as shown in Figure 3. The maximum powerconsumption is 5 VA.
6.2.5 SAFETY OUTPUT CONNECTIONTwo normally-open safety outputs are provided. Inlower risk applications (Category 2 or lower) themachine is commonly provided with a singleMPCE. In such cases both safety outputs should beconnected in series with the MPCE coil as shown inFigure 9. If the machine is fitted with two MPCEs(Categories 3 and 4), one safety output should beconnected in series with each MPCE coil as shownin Figure 10.

Figure 2 - PSSR/2 Dimensions6.2 ELECTRICAL6.2.1 GENERALThe connections for the PSSR/2 control unit areshown in Figure 3. Crimped ferrules should be fittedon all stranded wires. It is recommended thatelectrical installation is performed in the orderdescribed below.
6.2.2 SENSOR CONNECTIONSelect one or two sensor operation using internalswitch SW1 as shown in Figure 4. Access to theinternal switch is gained by using a screwdriver to	  2	   	  	  To protect the contacts of the safety output relaysfrom the effects of switching inductive loads, it isrecommended that arc suppressors should be fittedin parallel with the MPCE coils as shown Figures 9and 10. Arc suppressors must not be fitted acrossthe safety relay contacts.
To protect against the possibility of both safetyoutputs welding in, due to an overcurrent fault inthe machine circuit, 2 A fuses should be fitted inseries with the MPCE coils as shown in Figure 8and 9. This limits the current through the safetyoutput contacts to well below that which couldcause the contacts to weld.

www.tapeswitch.com	  	  	  	  3	   	  	  www.tapeswitch.com	  	  	  action normally-open switch between X1 and X2),press and release the reset button. On release theoutput relays will be energized and the O/Pindicator (green) will be lit.
(e) Actuate the sensor(s). When a sensor isactuated its indicator be off the output relays shouldde-energized and the O/P should be off.

Figure 9 - Safety Output Connection (Single MPCE)If the system operates as described above theinstallation can be completed. Before putting themachine into use the complete system should becommissioned as described in the sensor manual.
If the safety system does not operate as describedabove refer to the sensor manual for fault-findingprocedure.
7. TECHNICAL SPECIFICATIONSafety Performance LevelPLd (EN13849-1:2008)

Probability of dangerousfailures per hour (PFHd)1.03x10Power consumption

3 VAResponse Time13 msTemperature Range-10C to +55CReset FunctionAuto or ManualSupply Voltage24 VAC/DCSafety Outputs:Device TypeFigure 10 - Safety Output Connection (2 x MPCE’s)6.3 INITIAL CHECKINGRatingThe system can be checked at this point as follows:(a) Check that the sensor(s) is (are) connected andclear.
(b) Apply power to the control unit. DO NOTAPPLY POWER TO THE MPCE’S. The POWERindicator (red) should be lit, the SENS1 and SENS2indicators (yellow) should both be lit.
(c) For Auto Reset (where there is a link from X1 toX2), the output relays will be energized and the O/Pindicator (green) will be lit.
(d) For Manual Reset (where there is a momentary	  4	   	  	  ContactsMaximum Sensor Length-7Safety relayForce guided relays2 x normally open1 x normally closed (monitor)5 A @ 240 VAC100 MEOL resistor range5k4 min., 9k5 max.

Enclosure Protection RatingEOL resistor range

IP20For Customer Service Call1-800-234-8273www.tapeswitch.com