Wärtsilä strengthens its portfolio with load resistors

Wärtsilä strengthens its portfolio with load resistors

To get an edge in the competitive load resistance market, Wärtsilä expanded its offering to include load resistors. A part of Wärtsilä since 2015, Wärtsilä JOVYATLAS’s long experience in the resistor manufacturing business enables Wärtsilä to grow its product portfolio and launch a new series of load banks in September.

Text: Wolfgang Pastoor Photo: Wärtsilä

Although manufacturing load resistors is a relatively new business for Wärtsilä, Wärtsilä JOVYATLAS has a history of load resistor manufacturing for more than seven decades. By incorporating resistor manufacturing, Wärtsilä is able to provide better in-house packages for customers, extending the scope of delivery and the scope of application for customers in different industries and business sectors. The production portfolio of Wärtsilä JOVYATLAS ranges from the marine sector to generator testing.

Recently, Wärtsilä JOVYATLAS implemented a standardizing project for load banks used for generator tests. The products will be launched in September under the name JOVYLOAD CONCEPT.

The standardized load banks are used for testing generators or uninterruptable power supply (UPS)- systems. For example, hospitals use a UPS-system as a backup so they need to be tested. Besides generator tests, load banks can also be used for balancing or minimum load purposes. For instance, during the day, power consumption is much higher than at night. However, for the generator to run smoothly, it needs a certain minimum load during the night as well. This can be achieved via a load bank.

Fig. 1 - JOVYLOAD CONCEPT 500kW with transport and shock frame.
Fig. 1 - JOVYLOAD CONCEPT 500kW with transport and shock frame.


Jovyload concept and modular kit

The new JOVYLOAD CONCEPT includes basic load-bank-modules, with a wide selection of components and control units. The idea of a Modular Kit is to help customers choose the elements, as one would select the custom features on a new car, to meet their personalized needs for different applications. Basic modules range in power from 100 kW to 500 kW, load steps from 5 kW to 1 kW, and there are also different substructures, like a transport frame or vehicle trailer, castors or just feet for stationary use. Operation is possible directly at the load bank, by remote control or via web browser connection. The Modular Kit provides several more options, e.g. additional weather protection like air ducts, load cable sets with different plugs and control units with multiple options. A load bank module of 500 kW with transport and shock frame is shown in Figure 1.

Even though the maximum power of standardized load banks is 500 kW, it is possible to attain more power via a Master-Slave-Operation. This means connecting several load banks to one control unit at the same time. This is a special benefit to enable rental services to work with only one size/type of load bank, e.g. 500 kW, but have the opportunity to offer more power, i.e. 2 MW, to customers.

Standardized products enable Wärtsilä to sell load banks at a competitive price without extra engineering costs. For customers, the Modular Kit gives a clear picture of the range of options available. The variations and maximum power of the load bank series will be enlarged in the coming years.

The basic module consists of a switch cabinet and a load resistor compartment. The used tubular heating elements are assembled at the rear of the switch gear. The load resistor compartment is constructed with a double wall system for thermal insulation. The back is removable, and the switch gear mounting plate is hinged. This ensures easy maintenance of resistor elements.

The load fuses, contactors and all necessary control and monitoring devices are installed in the control cabinet. The load steps are wired in a star configuration onto copper bars with mounting holes or in a load cable connection. The star point is implemented as well and can tolerate full (100%) current load. Modules are provided with five different power ranges with load steps of 5 kW (cascading). In addition, load steps of 1 kW (cascading) are available. For the basic module, a substructure with an integrated fan is required to prevent overheating. All load levels of the load banks are secured and are switched off in case of a fan fault. Usual voltage is 3~400V, but versions for other voltage levels, like e.g. 3~480V or 3~690V or DC, are available upon request. A load bank trailer version of 400 kW is shown in Figure 2, and the same trailer version is shown from the rear in Figure 3.

Fig. 2 - CONCEPT 400 kW trailer version.
Fig. 2 - CONCEPT 400 kW trailer version.


Fig. 3 - CONCEPT 400 kW trailer version rear side.
Fig. 3 - CONCEPT 400 kW trailer version rear side.


The Modular Kit provides many options for control units and data logging. Several control and visualisation units like rotary switches, different touch panels and multifunctional meters are available.

Load banks can be either manually or remotely controlled. The basic manual control is to mount easy-to-use, rotary switches on the front door of the load bank. In an industrial area or at a project site, this configuration allows an operator of the load bank to use the switches even while wearing his protective gloves. A load bank with rotary switches mounted on the front door is shown in Figure 4 and 5.

Fig. 4 - CONCEPT stationary version and inside switch design.
Fig. 4 - CONCEPT stationary version and inside switch design.


Fig. 5 - CONCEPT stationary version.
Fig. 5 - CONCEPT stationary version.


Remote control is useful, for example, when a test is run outdoors but needs to be monitored from indoors. With a remote panel, it is possible to work at a distance of 25 meters and still access the important messages shown on the text display during a test run.

Furthermore, there are multifunctional meters available. They are installed in the switch cabinet of the load bank and show all important measurement data, such as current, voltage, power and frequency. In some models, the measurement data is stored in memory and can be read with a laptop via USB connection.

For more user-friendly functioning, there are touch-panel programmable logic controllers (PLC) available. The touch panels are installed at the switchgear of a load bank or within a remote controller with cabling of 50 metres. This type of control unit includes features like a data logger and programmable test runs. For instance, a program can be set beforehand to run the generator first for 2 minutes with 30% of the maximum load and then 2 minutes with 80%. In addition, program curves without any manual changes are possible to execute with the controller. Test data is stored by data logger and saved in the PLC memory. It can be read via computer and further processed as an Excel file or printed out. Moreover, control via web browser is possible with an internet connection, and it does not require any additional software.

Example configuration of CONCEPT loadbank
Example of configuration of CONCEPT loadbank


Special technology of jovyload products

The technology of Tubular Heating Resistor Elements is very specific. Inside a heating resistor tube, there is an electrical wire. To ensure proper electrical insulation for the resistor wire, the tube is filled with magnesium oxide. A resistance wire of 80/20 NiCr composition provides a very high accuracy of the resistance value even during continuous operation. The outer case is made of stainless steel, guaranteeing a long life.

These resistor elements are hermetically sealed and assembled directly on the switch gear. Due to this particular construction, a protection degree of IP55 can be ensured. The tubular heating elements create a very compact construction with less weight than other load banks on the market. The special design and the arrangement of the elements enable a low air outlet temperature even in the case of full load selection.

The production of load resistors is based on our state-of-the-art manufacturing methods. By means of simulation models, resistant materials are used optimally in the manufacturing process, permitting a cost-optimized production of resistors that directly benefits our customers.

Wärtsilä JOVYATLAS uses also other resistor elements like stainless steel grids or wire wound resistors. The choice of elements depends on the application and customer requirements. In addition, Wärtsilä JOVYATLAS manufactures neutral grounding resistors, braking resistors, starting resistors, discharging resistors, damping, and filter resistors. All these different types are used at transformer stations, offshore platforms, wind energy plants, cranes, port facilities, test facilities, vessels, yachts, railway transportation and urban railways. Wärtsilä JOVYATLAS has a production area of 2000 m² just for resistor production, including CNC laser cutter and punching machines.


The new JOVYLOAD CONCEPT products offer notable benefits to customers, by allowing them to execute load tests quickly from almost anywhere at any time. Load banks are light, compact and easy to transport. Different frames and substructures enable flexible use and transportation of the load banks to different rooms and environments. For instance, load banks mounted on a trailer can be transported by a passenger vehicle or a van. A stable transport frame with lockable swivel castors can be moved for flexible use in direct proximity of the test sample. In other words, variations of the same load bank series can easily and flexibly be used in different places indoors and outdoors.

Maximum performance in a minimum space

Demanding requirements of a city environment can be met via our load banks. Load banks have low air outlet temperature and low noise level <70 dB(A) at a distance of 3 metres. These are important factors in a small room or in an urban location, such as a data centre. Especially in a city environment, a low noise-level requirement can be hard to meet. In a small room, it is important that the ambient temperature remains stable. In addition, due to vertical air outlets no safety distances nor additional barriers to block exhaust air are needed. This also benefits customers using small rooms or spaces.

Reliability and safety

Load banks of JOVYLOAD CONCEPT type are robust, which enables reliable use under difficult conditions. The construction with transport and shock frames is designed for those frequently transported by forklift and either low lift truck or crane. The outside rubber elements prevent shock, and the protection class of the products is IP55. When used outdoors, various devices offer safety and protection against pollution and water penetration. The load banks have a perforated plate cover, air scoop with weather protection grid, high roof and weather protection border for the control cabinet door.

Control of the load banks is easy. Customers may choose a manual or remote control unit. Because of many options and switching stages, customers are able to achieve accurate test results. The load steps can be provided even with an accuracy of 1 kW.


By manufacturing load resistors, Wärtsilä can provide better in-house service for global customers and strengthen its share in the load resistance business. Load resistors are manufactured by Wärtsilä JOVYATLAS in Germany. Even if manufacturing load resistors is quite new business area for Wärtsilä, Wärtsilä JOVYATLAS has a history of manufacturing load resistors for more than seventy years. It provides load resistors for different industries and business sectors, including ships, trains and power plants.

Wärtsilä JOVYATLAS has implemented a standardizing project for load banks for generator tests and is launching a new series of load banks in September under the name of JOVYLOAD CONCEPT. For generator tests, the new JOVYLOAD CONCEPT provides a special load bank series from 100 kW to 500 kW in a very compact and easily transportable version.

If more than 500 kW power is needed, a combination of several load banks with one common control unit is achievable via a Master-Slave-Connection. The load bank modules are provided with a wide selection of components and control units in order to meet individual customer needs. They allow customers to perform load tests quickly, flexibly and reliably at any time and place. Demanding requirements of a city environment can be met via Wärtsilä load banks because of the low air outlet temperature and low noise level <70 dB(A) at a distance of 3 metres. Robust load banks can also be used under difficult conditions, and they can be manually or remotely controlled.

In the highly competitive load resistor business, Wärtsilä JOVYLOAD CONCEPT helps Wärtsilä broaden its scope of delivery and scope of applications for different projects, thereby providing better service for customers in the long run.

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