|
The crane drive controls the acceleration and speed of the motor in each of the main systems of the crane to achieve the required power and torque to lift and/or move the load (container). The logic control (solid-state logic or programmable) provides the logic sequence of each process function to ensure proper and safe operation of the crane.
Crane drive and control systems upgrades are a key method of enhancing crane performance. By accelerating its cycle times, a crane’s hourly handling rate and moves per year can be significantly improved.
When to consider drive and control retrofits:
- Due to age: After a lifecycle of 10 to 15 years, parts are out of production, difficult to procure or simply not available. Spare parts must be cannibalized or expensive custom-made parts must be fabricated.
- Reliability: At the ends of their service lives, drives and controls become unreliable and prone to breakdown, thus diminishing crane productivity.
- Need for higher performance. A new digital drive can be installed incorporating productivity enhancement tools such as crane management systems, higher crane speeds in some cases, and automation features.
After a technical evaluation of the entire drive and control system is performed, recommendations for upgrades or replacement of components such as drive, PLC controls and motors, gearbox, rope drum and brakes are given.
As a result of drive retrofit, speed increases to the main hoist and trolley can range from 5% to over 20%, depending on the particular crane specifications and economic considerations.
Speed increases can also be achieved through larger drum size, changing the gearbox with a higher gear ratio, or by increasing motor speed.
Example:
Penang, Malaysia
Hoist speed on two RTGs increased as follows:
- For Rated Load, from 9 metres/minute to 12 metres/minute
- For Empty Spreader, from 15 metres/minute to 20 metres/minute
1. Cristobal and Balboa, Panama: Ten MGM RTGs
2. PSA Tuticorin, India: IHI QC
3. Penang, Malaysia: Hitachi QC
4. PSA Singapore: One Samsung QC
5. Hong Kong, SAR China: Hyundai RTG
The port decided to upgrade the control and drive system on its QCs.
- Crane had been built in the 1990s and featured an analog drive system
- DC motor was overhauled
- Electrical room refurbishment:
1. Main transformer
2. Main hoist/gantry DC drive panel
3. Trolley/boom DC drive panel
4. Master controller PLC panel
5. Drive and PLC application software
6. Fully enclosed and air conditioned
A number of retrofit possibilities are available depending on present and future needs as well as budgetary considerations.
New DC drive using existing DC motors
- Replace generator field control or DC analog drive with new DC digital thyristor drive and programmable logic controller (PLC) system
- Retain all DC motors
New AC drive with new AC motors
- Replace generator field control or DC analog drive with AC inverter drive and PLC system
-
Replace DC motor with AC motors
New PLC
- Replace contactor-relay logic controls with new enhanced-functionality PLC system
Turnkey System Integration Services
Our complete turnkey package includes design and engineering, drive system assembly, installation, and commissioning. Our meticulous project planning and execution minimizes downtime, so cranes can be returned to service after 10 to 14 days of on-site installation and commissioning.
We collaborate closely with all major drive manufacturers:
- Siemens
- TMEIC-GE
- Schneider Electric
- GE-Fanuc
- Yaskawa
- Fuji Electric
- ABB
|
