Repairing Giant A-Shaped Portal Crane in an International Company

I going back to Bangi to delivery an Motor Inverter which is rushing for a replacement in SGL CARBON Company from a supplier, KVC SDN BHD. This is well-know brand,Allen Bradley motor inverter which is a programmable logic controller.


AC DRIVE POWERFLEX 400, 380-480V, 3PH, 10.5A, 4 KW, IP20, FRAME C.











In the afternoon, an electrical engineer, a technician and me go to SGL to diagnose the problems of whole electrical system of the A-shaped crane that fail or break down.

an example of the look of a double girder A-shape crane



My visitor pass with strict bar code.



The actual A-shaped portal crane is very high and we need to climb up to the main control box with its stair.





The View at the top of crane structure.





Control box ventilation system


Doing the setting and testing when finish the replacement work of motor inverter.






we go down again in order to do the testing via the control pendant below the crane system.







The repairing work is done. Then off the lights in side the big control box and close its casing.

Eletrical component purchase order list

I need to finish a task of electrical component purchase order list of a hoist package. First, I have to search the project profile to check what is the type of hoist.

Hoist Type : SWL 5 Ton STAHL SH5025-20 2/1 L2
9.0/1.5kW Hoisting motor
0.55/0.12kW Cross Travelling motor

From the data above, I have to search the nominal current ratings from the catalogue in order to pick only necessary and suitable electronic and electrical to be installing in the hoist control box.

Complete Hoist Control Box



The SLE 21 load monitor is already provided by STALH company.




This my first time to learn about function of contactor and its usage. The contactor of Telemecanique brand that I have select according to power ratings.






Timer Block LAD-TO and LAD-RO.

METALTECH 2010 at PWTC

08/05/10, Saturday - After half-day work, I follow my Electrical Department Manager and colleague go to visit METALTECH 2010 at PWTC, a exhibition of metal tool, metalworking machine and robotic equipment. This a really special event for me to open my eye in today's high technology factory equipments that I never see and tough it before. There are many oversea exhibitors such as Singapore, Korea, Taiwan, German, India, China and others.

Even though the theme title is METALTECH, but these event show a lots of machine and robotic that involving electrical and software design. Some of the machines need programing to run it for the precision manufacturing process.

My visitor pass with the name of company



There are 5 hall in the exhibition event.

Choosing the conductor bars for crane system

The Main Supplier of the conductor bars for our company are Conductix Wampfler(a Germany Company) and IGA (Spain Company). I need to learn and know more about these product before I starting with my calculation of voltage drop, in order to choose the most suitable conductor bars. The manager want me to focus on Wampfler Single Powerline 0813 and LM-4 of IGA.



Wampfler Single PowerLine 0813
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Nominal Current [A]: 200 - 1250
Nom. Voltage [V]: 690 (1000 V with add. insulators)
Support Spacing [m]: 2,5

Standard application data
- Nominal Current (at 100% duty cycle) [A]: 200 | 320 | 500 | 800| 1.000 | 1.250
- Voltage Grade [V]: 690
- Rail Length [mm]: 5.000
- Outside-Dimensions (Pol) [mm]: 32,0 x 42,0
- Operating Conditions: for indoor and weather protected outdoor applications
- Track Configuration: preferably for straight courses / curve segments available


Special features
- High availability in strong industrial environment trough several material
- High level of safety trough insulation profiles with integrated finger safe protection
- Easy and exact mounting with multiple hanger clamps for (3, 4 and 5 pol)
- Free and unlimited combination for multiple amount of rails
- Radius segments for curves available


Main applications

Process and EOT(Electrical Overhead Travelling) cranes
People Mover
Container Cranes
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IGA LM-4



Mobile power supply feeding point along the IGA conductor in the factory







Channelling electrical protection with the use of current displacement. Applicable for security, like mobile electric power supply with fixed paths (straight or curved) on crane, hoist, moving electrical machinery, moving equipment and in general, wherever it is necessary to have mobile power.


Find the Nominal Current of those motors in cranes system





Determine Voltage Drops and Choose L feed-in

The Voltage Drop should be less than 2.5%

SEE Electrical drawing software product of Siemens

Most of my time in 4th week was doing the Electrical circuit drawing using the SEE electrical software that company brought from E-solid SDN BHD with the price of about RM 5000 per each license.

Firstly, I studied the manual for two day. I had a chance to try myself to use the software at a senior electrical engineer desk-top because he went for outstation in China. Below is some of the part manual of SEE software.







From Wednesday to Friday, I started 4 electrical circuit drawing that my manager given to me to design. There are three different type of 5 ton Electrical Overhead Travelling Crane for the customer in Penang, which is TEIK HOOI ENGINEERING SDN BHD and one 10 ton Electrical Overhead Travelling Crane for IMO (INDUSTRIAL MATERIALS ORGANIZATION (L.L.C) Industrial, Hydraulic, Electric Tools & Equipments), a project in Suadi Arabia.


The Customer

Company's Engineer Training

24/04/10, Saturday - All the senior engineers, a uniten ME student and me undergo a training course organised by the company itself. This lecture was conduct by our boss, Execellift CEO in the meeting room. He taught the case study of a "interesting" structure in underhung crane (a bit different from now they are manufacturing in the factory) that was being done in the beginning of his business in 1994. Most of this lecture involved mechanical theory and functional. Despite that I am an electrical power engineer student, I should know more about it in order to have collaboration with the mechanical department. The crane system is not only mechanical engineering works, but also need the electrical application to work in collusion. So we need M&E consultation.

He showed us the slides with his hand sketch of design plane that done in 1995. It is almost the same in format compare with the Auto CAD software that we use in nowadays. The only diffrent is hand sketch less of neatness. I learn a lots from the boss' training lecture and know more about the history of the company.

Case Study of Underhung Crane

Factory site's work

Today, Assistance Manager give me a check-list to make sure 8 chain hoists are ready in packaging in order that stocks can deliver to the customer's factory tomorrow. When I meet with the store-keeper, he said that he don't know any instruction from the executor about this task. So that, store-keeper and other workers have to search for stock. This task take a extreme long time because they need to lift and move 8 heavy chain hoists. Then, they will only packaging those hoists together with other component and epquipment. I have to work over the office time with them until 8 pm. Finally, they can't finish the work by this evening before knock off. I follow the instruction that need to take down the series number of each hoist and require "DO"(delivery order) from accounting department. I am unfortunely can't find those certificates of hoists too(just only 2 are found). I hope that we can done in the early morning of tomorrow.

The company gave me a safety shoe in last week.


Check List


My workplace





The lastest STAHL Logo



STAHL ST20 Elecrical Chain Hoist able to lift up 1000 kg or 1 Ton loads



Small hook with SWL (Safe Working Load) of 1 Ton.