Ports
Amclyde, American Hoist, Americas, Amreolver, CLYDE, Field Service, Job Report, Portal Cranes, System Upgrades, USA

Crane Control Upgrade in Seattle Port

June 23, 2020
10:39 pm

June 23, 2020
10:39 pm

Alatas Service	System Upgrade
Location	Seattle, USA
Crane Manufacturer	Clyde
Crane Model	28

Alatas Americas was contracted for a crane control upgrade and drive system reconfiguration for a portal crane in Seattle.

Our client’s crane had experienced substantial downtime over the years due to an outdated hoist control system. There had also been a few instances of dropped booms due to operator errors and the releasing of the drums clutches (frictions) before dogs being engaged to hold the drums.

In addition to the boom issues, wear had begun to show on the friction band brakes due to the band brakes needing to be partially engaged while lowering a heavy load.

Finally, if the band brakes were not engaged while lowering the drum, it would gain too much speed. This meant it could lead it to run away as there is no system installed to prevent over-speeding of the motor and draw works.

Our Solution

The Alatas team based in Seattle were able to solve all of these issues by installing a new control system with a PLC, new hoist motor and VFD drive system.

The new control system and PLC now provide interrupts and status inputs to the cab mounted HMI for safer operation. The control interrupts are listed below.

New Control Interrupts

The hoist will not operate if any of the following items are present during the PLC scan.

Drive fault is present
E-stop is depressed
Failure of the 480vac power is detected (or if a phase is swapped)
Hoist motor over-temperature is detected
Hoist motor fan over temperature is detected
Short circuit of the hoist resistors is detected
Fault in the hoist DBU (Dynamic Braking Unit) is detected
If the system pressure is not greater than 95psi you will not be able to engage a drum clutch (friction)
If the drum clutch (friction) is not greater than 95psi you will not be able to release a dog
If a drums dog is not engaged you will not be able to release drum clutch (friction)
If an upper limit is reached (Aux A2B, Main A2B, or Boom upper limit) the hoist will no longer operate in the up direction (unless bypass switch is activated) Hoist will only allow down operation

The new motor and hoist VFD drive allows for smooth operation as well as a higher amount of control over all ranges of load weight.

The VFD along with the motors control interface only allows the drum to run at the input speed given to the drive through the joystick input from the operator.

This eliminates the issue of having a runaway load or boom while lowering. It completely eliminates the over-speed issue that the old motor and control system would allow.