The functionality of various frequency converters may significantly differ, which defines the equipment cost. Depending on the requirements for crane functions, its operating mode, the engineers of the engineering department of Dvesta company will help you to choose an ideal manufacturer of frequency converters.
The company’s engineering department has completed projects using a great variety of frequency converter models. Due to our accumulated experience, we can produce control systems according to any requests of operational services and using the equipment of Siemens, Schneider Electric, Mitsubishi Electric, Danfoss, Vacon, ABB, Control Techniques, Omron, etc.
Warranty period
The warranty period for all the equipment produced by Dvesta is 18 months and is calculated immediately upon crane commissioning, but no more than 24 months from the production date indicated in the Product passport.
The warranty period can be increased or prolonged upon agreement between the contracting parties. For more information, please, contact our Sales department.
Terms of warranty
Warranty cases occur when the fault of the producer is evident and fully proven, and also in case these do not involve any 3rd-party actions, incorrect or careless equipment usage and other factors that produced breakdowns of the equipment or its constituent parts.
Service maintenance
Dvesta setup and programming department specialists provide service maintenance for cranes and crane equipment.
The periodic service maintenance includes:
The recommended frequency of the recurrent service maintenance – quarterly.
The service maintenance of cranes also implies unplanned emergency calls of drive setup and PLC-programming specialists to analyze and restore the operation of the crane electric equipment.
Remote diagnostics and programming
In order to minimize the expenses on emergency calls of the maintenance crews, we suggest equipping your crane control systems with special remote diagnostics sub-systems. These systems can provide Dvesta setup and programming specialists with quick access to PLC and frequency converter software for remote detection of the most of possible system failures and the ways to resolve them.
Scope of delivery of the crane control system is agreed upon individually for each project, whereas the Delivery division sheet is prepared, and the following can be included:
Scope of delivery
Spare parts, tools and accessories
At the Customer’s request a programming device SIMATIC Field PG M (or its analog – a laptop with MPI/PROFIBUS adapter) can be supplied with pre-installed license or trial software SIMATIC STEP 7, TIA PORTAL, STARTER, including an integrated project of the crane software.
Firmware project kit:
The engineering department of Dvesta company uses modern design techniques, which ensures completion of complicated projects as soon as possible having a possibility of instant changes at all manufacturing stages and during precommissioning works. The projects completed are easy to use, comprehensible and easy-to-interpret for the maintenance staff.
The electrical part of the project includes the following interrelated documents:
To prepare technical documentation, CAD EPLAN Electric P8 is used. At the moment this is the most popular CAD system to design producible electrical equipment.
The advantages of using CAD involve increase of work efficiency and saves the designer from conventional functions. Qualification and experience of the specialists are indispensable while preparing sheet-oriented solutions, defining project functional structure, electrical calculations. Report generation (List of elements, List of cables, etc.) is performed by CAD automatically and does not require the designer’s participation, which reduces error possibility to zero.
Wiring diagrams are easy-to-interpret for both electricians and programmers. All connections can be seen in a graphic designation of the device. Extensive poke-through system of cross-references helps to control signals and potentials along the whole diagram.
The samples of documents are available on links below:
The equipment for crane mechanisms control can be located either in electrical cabinets or in a special container-type E-room. Equipment location choice depends on total power of electric drives installed, crane design, climatic conditions of crane operation, etc.
E-room
Equipment location in an E-room has certain significant advantages comparing to electrical cabinets:
The following can be considered as disadvantages of E-room use:
Design features
The E-room is made based on weld-fabricated construction and coated with sandwich panels with incombustible insulant. Entrances to the E-room are located at side ends and equipped with wind porches. The equipment inside the container is shielded from the passage with protective barrier to avoid accidental contact with conductive parts during spontaneous crane movement. The number of naked surfaces under voltage is minimal.
The E-rooms are equipped with trays for documentation, lighting, supplementary sockets (~220V). For maintenance staff a folding table and seats are provided.
Cooling of power equipment is performed using special crane air conditioners of various manufacturers (Pfannenberg, WeissHaar, DoKon). External and internal air circuits are isolated from each other, so that dust ingress through the air conditioner is not possible. The air conditioners require no special maintenance.
Protection class rating of the E-room shall be at least IP54.
Electrical cabinets
The most frequently used method of equipment location on cranes is location in electrical cabinets. Electrical cabinets can be one-piece or composite with unilateral maintenance. The equipment is placed there on mounting panels made of fiber-glass plastic or galvanized steel. Protection class rating of the cabinets is at least IP54. To maintain necessary climatic conditions, the cabinets can be completed with industrial heaters, fans with filters or air conditioners. If the crane operates in the conditions of significant daily temperature differences, then the inside of the cabinets is covered with porous insulant.
The use of electric cabinets is reasonable for low power systems installation, where the requirements for minimal air volume for frequency converter cooling are met.
Comparison table of two most popular drive types used on cranes at present time: frequency converters and thyristor-based drives.
| Drive type | DVESLY drive | Frequency converters |
|---|---|---|
| Motor type | Asynchronous motor with slip-ring rotor | Asynchronous motor with squirrel-cage rotor |
| The principle of speed control | Resistance change in the rotor circuit of the motor | Voltage and frequency change in the stator of the motor |
| Type of control | Thyristor key-switch | Frequency converter (inverter) |
| Regulation dpeth |
До 1:10 |
До 1:100 |
| Temperature operating range |
  -40°C ─ +60°C |
 0°C ─ +40°C |
| Working in dusty areas (eg, cement) |
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| Price comparision if motor power less than 18,5kW |
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| Price comparision if motor power more than 18,5kW |
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| Energy efficiency |
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| Overload capability |
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| Personnel qualification requirements |
electrician |
electrician, |
| Terms and cost of repair works |
Not more than 60 minutes. Cheap spare parts. Parts replacement only. Short delivery time of parts. Usually, all the necessary components are present in the supply of spare parts. |
Expensive spare parts. Replacing only major parts. Most often, spare parts are not available. Powerful drives can be manufactured individually more than a month. Recommissioning often required after changes. |
| Flexible parameterizing |
Speeds defined by hardware and can't be changed |
Speeds can be changed by software |
Auxiliary functions:
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| 4-rope grab controller |
Synchronization of winches occurs automatically due to the physical principles of regulation |
Winches synchronization requires additional electrical connection between frequency converters. Complexity is determined by adjusting brands drives and requires special knowledge of the commissioning engineer ACS. |
Dvesta today provides a full range of works on the development of control systems for new, modernization and reconstruction of old cranes. So far more than 100 cranes upgraded using thyristor control systems.
Read more about Modernization and reconstruction of cranes.
Comparison table of two most popular drive type used on cranes at present time: frequency converters and thyristor-based drives.
Programmable logic controller (PLC)
The PLC software makes the following options possible:
The software is performed in a standard programming language, LAD. Fragments of mathematical logic and indirect addressing for work with data archives can be performed in the STL language. Each unit, network goes with detailed comments in Russian or English. All variables used are named according to the recommendations of the Hungarian notation and include short description, position designation on the wiring diagram of the device connected with this signal.
Operator’s panel (HMI)
The operator’s panel in the crane cab displays in real time mechanism movement directions, speeds received from control panel command device.
Using an engineering menu of the operator’s panel you can do the following:
Operational information and crane operation statistics are stored on a memory card in a cyclic archive for at least 45 days. Statistical information in the archive can include the following characteristics:
