| Variable Speed Drives |
Variable speed drives allow the operation of any IBC system to be more user friendly and much more efficient when compared to systems using manual damper valves and fixed speed blowers. The precise control allows operators to make fine adjustments that are nearly impossible using damper valves. The fine adjustments can mean the difference between a stable bubble and an unstable one. However, there are several considerations that should be investigated before selecting the drive. Not all drives are created equal. There is a variety of features available that may or may not be necessary for the IBC application. In this case, the general application is a fan. This most commonly calls for a general purpose, variable torque drive, with linear ramping, coast to stop, and at least one configurable dry contact used to report drive faults. Other features, including interface protocols are also available at extra costs. Review the headings below for additional information on the most common VSD concerns. Then review the compatible drives list and also the drive checkout procedure below. For drive interface documentation, please click here for the DRJ service section (requires registration). |
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| Flux Vector or General Purpose | Variable or Constant Torque | Capacitor Banks and Braking Resistors |
| Flux vector drives promise very tight speed control tolerances, but there is significant effort required to achieve this performance. For fan applications, the fan has to be separated from the blower motor and calibrated. This takes considerable time and the value is difficult to justify. DRJ successfully uses general purpose drives for all IBC applications. | Variable speed drives come in two varieties, constant torque and variable torque. For all IBC and airing fan applications, variable torque is sufficient. This is because at low speeds, the fan requires very little torque to initiate spinning. Generally speaking, the variable torque drives are less expensive. | As drives become available at lower costs and the drive packages getting smaller, the limited ability to dissipate energy can cause nuisance trips that shut down the extrusion line. The specific fault is over voltage on the DC buss. Plan on purchasing the braking resistor kit for these small package of drives. Contact us if you have any questions about the drive you are considering. |
- Compatible Drives - .PDF (78KB)
A list of the current drives that are compatible with the IS-IBC1 system and any special interface notes.
- Checkout Variable Speed Blower Drives - .PDF (704KB)
If the drive is not on the compatible list, the customer can test the drive against the functional tests listed in this document.
