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WHAT IS A PPI SMART ROLL?
The PPI Smart Roll is a PPI idler roll with a sensor built inside the roll . All the components inside the roll are aligned, ready to use, and
maintenance free . As the roll rotates the sensor opens and closes a circuit to produce on/off pulses . Additional electronics such as the
Smart Monitor or PLC are needed to convert these pulses into a usable function .
WHY IS THE CLEAN SIDE RETURN (CSR) PREFERRED?
More versatile:
Because the CSR is independent of the belt width it can reduce your spares inventory . Putting Smart Rolls into troughing
or return positions can cause increased inventory expenses because each belt width requires a different Smart Roll spare .
Lasts longer:
The CSR Smart Roll practically eliminates load on the roll because it does not support the weight of the belt or material .
The CSR is more forgiving in dirty environments.
The CSR can be mounted in a protected location . The CSR Mounting bracket is designed
to rotate so that if material gets between the roll and belt it is free to roll over the debris . The use of CSR is not recommended for
reversing belts .
WHAT IS A PPI SMART MONITOR?
The PPI Smart Monitor is used to convert the pulses from the Smart Roll into a usable form . Using the Smart Monitor a critical speed
is set, when the speed falls below the set point the Smart Monitor will energize a relay . The relays can then be wired into the conveyor
controls . The Smart Monitor also has a ramp up timer that can be set from 0 seconds up to 30 seconds .
IS A PPI SMART MONITOR REQUIRED WHEN USING A PPI SMART ROLL?
A Smart Monitor, PLC, or other similar device is required to read the Smart Roll pulses and convert them into a usable form .
CAN A PLC BE USED WITH THE PPI SMART ROLL?
Yes, the Smart Roll uses an inductive proximity sensor capable of handling most situations . It is normally open and can be wired in a
20-250 VAC or 10-300 VDC circuit .
IS IT POSSIBLE TO TEST THE SMART ROLL SENSOR BEFORE IT IS INSTALLED?
Yes . The test equipment must be able to apply power and detect when the circuit is opened and closed . There are several sensor testers
on the market; Contrinex, HTM and others make sensor testers that can test the Smart Roll sensor .
IS IT POSSIBLE TO TEST THE ROLL AFTER IT IS INSTALLED ON THE CONVEYOR?
Yes . Using a sensor tester mentioned above, the Smart Roll must be disconnected from the Smart Monitor or PLC, whichever is being
used, before the sensor tester is connected .
WHY DOES PPI NOT RECOMMEND USING A CLEAN SIDE RETURN SMART ROLL WITH REVERSING BELTS?
When the belt and material reverse the Smart Roll could catch and flex the wrong direction, damaging the wiring and Smart Roll .
WHAT DOES PPI RECOMMEND USING WITH A REVERSING BELT?
PPI recommends using a Universal Mount Smart Roll . This mounting option allows the Smart Roll to stay in contact with belt when the
belt is moving in either direction .
CAN THE SMART ROLL / SMART MONITOR DETECT BELT DIRECTION?
No, the Smart Roll only produces pulses and the Smart Monitor reads the pulses . The Smart Roll / Smart Monitor can only indicate that
the roll is turning, i .e . the belt is moving, but cannot indicate the direction in which the belt is traveling . In addition the Smart Roll / Smart
Monitor cannot be running one direction, stop, and then start running the other direction and continue uninterrupted operation . In this
case, when the belt stops the Smart Roll / Smart Monitor will go below the trip point and energize the relay . If this is required, a Smart
Roll with a 4-20 mA Smart Monitor (see Appendix A5) in conjunction with a PLC, this functionality could be programmed .
DOES THE SENSOR INSIDE THE SMART ROLL HAVE OVERLOAD PROTECTION?
To minimize possible damage the sensor includes short circuit and overload protection .
HOW IS THE SMART ROLL SENSOR RESET IF THE OVERLOAD PROTECTION HAS BEEN TRIGGERED?
To reset the sensor, power to the sensor must be removed and the roll turned . Turning the roll will move the target away from the
sensor to allow it to be reset . Using the 90° elbow conduit access port, disconnect the wires that provide power to the Smart Roll .
Rotate the Smart Roll several revolutions and then reconnect . The sensor is now reset and power can be reconnected . PPI recommends
determining and correcting the cause of overload or short circuit prior to re-energizing the sensor . See the Troubleshooting section for
additional information .
IS THE SMART ROLL AND SMART MONITOR INTRINSICALLY SAFE?
No, Intrinsically Safe Smart Rolls and Smart Monitors are not presently available .
FREQUENTLY ASKED QUESTIONS
