Braking resistors for inverters are used to dissipate energy during braking phases. Depending on the application, solutions with different electrical and construction characteristics may be required.

When the inverter manufacturer or resistor reference is already known, Fairfild provides a Cross Reference that allows users to consult the matches available on the website and verify the associated Fairfild model.

The tool therefore makes it possible to start from an existing reference, check the associated Fairfild model in the relevant table, and then review its characteristics in the technical datasheet.

1. Inverter braking resistor: where to start?

When the search starts from an inverter that has already been identified, one of the first pieces of information available may be the inverter model or the reference of its braking resistor.

The Fairfild Cross Reference organises this information through tables dedicated to different manufacturers. Depending on the table, the inverter model, the resistor reference shown as BR REF., the values in the NP and R columns, and the associated Fairfild model are provided.

For some manufacturers, a reference from another manufacturer is also included. The structure therefore makes it possible to compare the information already available with the matches listed by Fairfild.

2. Which manufacturers are included in the Fairfild Cross Reference?

The inverter section includes references for Siemens, Vacon, Danfoss, GE Power Controls, Bonfiglioli, ABB, Schneider and Leroy-Somer.

Each manufacturer has its own table listing the available matches.

3. How to identify a braking resistor for a Siemens inverter?

For Siemens, the Cross Reference includes various references associated with Fairfild resistors.

The tables include, for example, models from the RFD, RFH, RAF and RFZ/C families. The reference G85139-B1620-U187-A appears in two rows of the Siemens table: for 250W-370W-550W-750W inverters it is associated with the Fairfild RFD 50 model, while for 1.1kW-1.5kW-2.2kW it is associated with the RFD 100.

There is also a section titled “Sinamics S120 + Micromaster 440 BookSize Format”. In this table, for reference 6SN1113-1AA00-0DA0, with NP 300 and R 17 values, the Fairfild RFZ/C 300 model is indicated.

This allows users who have a Siemens reference to directly verify the match listed by Fairfild and continue evaluating the indicated product.

4. Cross Reference for Vacon, Danfoss and other inverters

The same consultation method is also available for the other manufacturers included in the Cross Reference.

For Vacon, for example, models such as FR4/FR5 and FR5 are listed, associated respectively with different resistor references and Fairfild models such as RFD 150 and RFD 300.

The section also includes tables dedicated to Danfoss, GE Power Controls, Bonfiglioli, ABB, Schneider and Leroy-Somer.

The inclusion of different manufacturers makes it possible to use the same tool starting from the available reference and, where present, verify the associated Fairfild model.

5. From the Cross Reference to the resistor datasheet

Identifying the match is the starting point for further product evaluation.

The families listed in the Cross Reference have different characteristics. The RFD is a wire-wound resistor on a cement-coated mica plate, immersed in quartzite sand and housed in an anodised aluminium case.

Other families listed in the Cross Reference, such as RFZ/C, also have their own construction and electrical characteristics.

Once the associated model has been identified, the relevant technical datasheet should therefore be consulted to review the specifications of that resistor.

6. Why check the individual model?

The presence of a model in the Cross Reference indicates the match listed by Fairfild for that specific reference.

Before making a selection, however, it is important to review the characteristics of the individual product through the available technical documentation, checking the parameters provided in the relevant datasheet.

For example, Fairfild datasheets include information such as resistance value range, continuous rated power, protection degree, rated insulation voltage, optional features, sectors and intended applications. These data may vary depending on the family and model considered.

7. Fairfild: from inverter search to resistor

The Fairfild Cross Reference makes it possible to start from references relating to different inverter manufacturers and verify the associated Fairfild model in the available tables.

Once the match has been identified, consulting the technical datasheet makes it possible to review the characteristics of the indicated resistor and the data relating to the specific solution.

For more information on braking resistors for inverters and to assess the most suitable model for a specific application, contact us.