Frequently Asked Questions
- Can the speed of the Power Moller be changed?
The speed of the Power Moller is determined by the reduction ratio of the gearbox to be mounted to the motor, so once the gearbox is mounted, the resulted speed isfixed. In case of AC Power Moller, that employs induction motor, the only way tochange or vary the speed is the use of frequency inverter to vary the frequency;higher the frequency, higher the speed and vice versa. The speed of Power Moller with 4P motor can be varied within the frequency range between 30 and 90Hz, and the speed of the one with 2P motor can be varied within the frequency range of 30 and 70Hz.
Note: Frequency inverter is NOT applicable for the Power Moller rating 300V or higher.
In case of DC Power Moller with magnetic motor (DS series), the speed can be varied byvarying the input voltage within the range of +/-10% of the nominal voltage. In case of DC Power Moller with brushless motor (FS, FE, FP series), the speed can be varied by the integral potentiometer on the motor driver card supplied with the unit.
- What Power Moller units are UL recognized?
Following Power Moller units (with some modefications depending on the motor type) are UL recognized:
- I need to precisely stop my product on a conveyor line.
Are brakes available on the Power Moller?
Yes. Brakes are one of the popular options available on many Itoh Denki Power Mollers. They can eliminate load inertia and enable precise stopping. The electromagnetic brake is engaged by spring force when power to the motor is interrupted.
Examples of applications include:
a) In automated conveyor lines, it is sometimes necessary to precisely stop or position the article being transferred. In these, the optional built-in electro-magnetic brake should be used.
- when no powered, the built-in electro magnetic uses spring force to lock the motor and prevent the tube rotation. The motor is released when the brake is powered (energized). Ordinarily, the power to the brake and motor is controlled simultaneously.
- In most cases, an external mechanical stop can be eliminated by using Power Moller with the built-in brake. However, the stopping distance may vary slightly depending on the load, speed, etc.
b) In gravity lines, it is often necessary to control the descent of the load to prevent damage to the articles accumulated at the end of the line. In this case, the standard Power Moller can act as a brake roller.
- when the rotation speed of the power Moller is increased by 10-20% from its nominal speed, it functions as an induction generator and braking torque is applied to the load.
- By incorporating Power Moller at several points in a self-traveling gravity line, speeding or congestion of the load will be prevented.
Since the Power Moller 24 DC models come standard with dynamic braking, the mechanical brake is made to operate in conjunction with the dynamic brake. In operation, the dynamic brake is used to slow the Power Moller 24, at which point the mechanical brake engages for a more positive hold. The mechanical brake will stay engaged even in the event of a power failure. Using this two-process brake feature will extend brake life.
Maximum continuous energized time is 30 minutes with a 70% duty cycle. Braking characteristics can vary by Power Moller model and weight transferred. Contact ITOH DENKI for additional information.
- How do I specify the length of a Power Moller?
In determining a correct length of the Power Moller required, you should first obtain the between frame width of the conveyor you will be mounting the Power Moller on. If this dimension is in inches, convert the dimensions to millimeters as all Power Moller tube lengths are in metric units. From this dimension, subtract 12 to 15mm for bearing endcaps (5mm each) and clearance (2 to 5mm) to achieve the correct tube length. For PM763BS, the deduction will be 30mm and 35mm for IPGC units.
- How does the bottom surface of my product and the level of the rollers affect roller performance?
The bottom surface can greatly affect a Power Moller performance.
Some concerns are:
a) If the bottom surface of the load is not flat or conveyor rollers are not level, then the Power Moller may rotate freely and the load may not be transferred or may tend to drit.
b) Transferring light load (less than 5kg) may be impeded by the resistance of idler rollers. Check to be sure that the idlers spin freely and investigate the use of slave driving non powered idler rollers.
c) Due to the packing (binding) bands, bulging of the bottom of the load, etc., the load my lean to one side during transfer. The use of each end sectional rubber laggings on the Power Moller would facilitate a straight transfer of the load.
- How do I calculate the tangential force of Power Moller with rubber lagging?
Tangential force is obtained by the formula torque (kg) divided by roller radius (cm). For instance, if you put 3mm rubber lagging on PM570AS-15 (57mm diameter roller), the resulted tangential force will be smaller because the radius becomes larger:
Torque of PM570AS-15 is 12.6kgcm
Radius of the roller with 3mm lagging is 3.15cm
12.6kgcm÷3.15cm = 4.0kg (tangential force of PM570AS-15 without lagging is 4.4kg)
- Is Power Moller available with explosion proof option?
No, Itoh Denki is not manufacturing nor offering any Power Moller with explosion proof option.
- What is the material used for Power Moller’s roller tube and end housings?
Power Moller’s roller tube is drawn carbon steel tube (seamless) with zinc plated finish as standard. Stainless steel tube or hard chrome plated finish options are also available. End housings of the power Moller are made of die-casted zinc as standard,but end housings for waterproof option are made of stainless steel.