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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
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