ICT MOTORS
EXTRUDER DUTY MOTORS
(972) 906-7445
440 Wrangler Dr Suite 100 Coppell TX 75019 US
No. While the HP of the drive remains the same, the torque necessary to turn the shaft is significantly different.
Yes. The XD motor is only available as a direct couple motor, roller bearings cannot be added.
No. You do not need to oversize the drive and motor when converting to AC, as long as you are using the right drive and motor and are not over-exciting the field of the DC motor to increase torque. AC Vector Motors have a wider (CTSR) constant torque speed range (1000:1) as compared to DC motors (10:1). This indicates that it can maintain torque at lower speeds without overheating. Also, AC Vector motors usually have a constant blower fan with filter similar to DC mounted opposite the shaft-end of the motor.
Do I need encoder feedback?
No. The speed regulation of a DC drive is 0.5% with a DC tach, while the speed regulation of an AC drive in Open Loop Vector is 0.2%. Although, an encoder is required on applications associated with web and tension control such as primary and secondary nips or application requiring high precision such as medical tubing. Using an encoder on an extruder will fight the pressure and slowly destroy your gearbox as it is not designed for this servo level response time. If someone recommends a servo performance on a large HP extruder motor, you are listening to the wrong person!
Do I need to oversize my AC drive or motor?
What are bearing currents and can they reduce the life of bearings?
Can I replace my 1150 RPM DC motor with a 1750 RPM AC motor?
Can I increase throughput?
Yes. This is especially true when using a NEMA frame motor, which is much larger. The XD motor is a laminated frame motor, which is typically shorter than the DC. While it is an IEC frame, any change from DC will result in a different footprint for the motor.
Is there a limit of how far away I can mount the AC drive from the motor?
ICT is a leading organization in the plastics industry that focuses on DC to AC conversions for extruders. With almost 1,000 extruder conversions across the US, we can give you guidence on the selection and motor of choice, and this motor is the one we had designed and highly recommend. Selection is simple, match the HP and RPM. Determine the conduit box location as this is fixed. These motors do not have Roller Bearing for belted loads, so you will want to give us a call if the motor you seek is not listed.
To make things easier, we added this list of commonly asked questions from customers like you asked when converting.
Yes. Bearing currents can reduce the life of bearings in an AC motor. They are caused by stray magnetic flux that induces a voltage on the shaft which discharges through the bearing causing pitting. These currents can be mitigated by specifying the Extruder Duty motor that was specified by ICT. This motor has a shaft grounding ring and insulated bearing, both of which increases bearing life.
Doubtful. Just because it fits, does not make it a good idea. AC drives have different heat ratings than DC and the drive may overheat in the same enclosure. This is especially true in applications that are greater than 100 horsepower. The watt loss of the drive can be obtained from the manufacturer to determine if there is appropriate cooling.
Yes. Distances greater than 150 feet require special provisions to ensure motor reliability which will increase the cost of installation. It is best to mount the drive close to the motor instead of in a control room that is too far away.
No. DC drives are all “Heavy Duty Rated” for applications such as extruders. AC Drives are both “Normal Duty” and “Heavy Duty” rated. Normal Duty is for pumps and fans and has a 110% overload capacity for one minute, while Heavy Duty is for applications such as extruders which has an overload capacity of 150% for one minute. The XD motor is rated at 160% OL for 1 minute, which is even better.
Are AC drives rated the same as DC drives?
Can I put the AC drive in the same enclosure as my DC drive?
Maybe, this is more dependent on your mechanics such as your gearbox and screw than the drive and motor. If the gearbox and screw can take the additional torque and speed, then it is possible to increase the horsepower proportional to the speed resulting in more throughput.