New Industry Products

Bel Power Solutions Unveils Upgraded Subrack System For Railway Operations

April 11, 2022 by Gary Elinoff

The new series of devices accommodates up to six 250 W AC/DC cassettes into one 19” rack system.

Seeking to enhance its previous power supply subrack system offering, Bel Power Solutions announced on April 5 its new LRSA series, which employs the company’s LR2320-9 or LR2540-9 converters in tandem to provide power, in up to 78 different voltage and current combinations, to railway control center operations. 


The LRSA Series. Image used courtesy of Bel Power Solutions


The new system’s six cassette capacity is a two-slot upgrade over Bel’s prior LRS MK007 Series. This roomier LRSA series offers single or dual output voltages from 12 to 60 VDC. Total output power of up to 1500 W is possible, with the system able to operate from input voltage ranges of 90 to 264 VAC at 50 to 60 Hz.


Railway Power Components

The LRSA subrack system is designed to provide redundant voltages and power for the harsh conditions encountered in railway and subway applications, which require high-performing, reliable power systems capable of upholding tough safety standards. 

“With this new system, railway system operators can decrease outages, and operate safely and seamlessly in harsh conditions for years to come,” said Bel Fuse President and CEO Daniel Bernstein. 

The LRSA series meets international railway standards EN 50155, EN 50121-4, and AREMA. EEPower recently covered EN 50155 and AREMA, in addition to a number of other national and international railway safety standards, in depth in an article from CUI’s Ron Stull. 


The LR2320-9 and the LR2540-9

As mentioned, the LRSA Series employs up to six of the company’s LR2320-9 and LR2540-9 Melcher AC-DC power cassettes in combination to achieve desired outputs. 


The LRSA series has two more slots than its predecessor, the four-slot LRS MK007 series. Image used courtesy of Bel Power Solutions


Both cassettes supply 240 W of output power and operate over input ranges of 125 to 264 VAC, or from 125 to 300 VDC.

  • The LR2320-9 supplies two separate 12 VDC, 10 A outputs.
  • The LR2540-9 provides two separate 15 VDC, 8 A outputs 

Isolation allows each output to be connected in series or parallel, to double output voltage or power.


Important Features

  • Excellent surge and transient protection
  • Inrush current is limited
  • Series members feature 3000 VAC of isolation between outputs, alarm signals, and the metallic chassis ground
  • The cassettes are hot-swappable
  • Power factor is 0.93 or better
  • Harmonic output limited as per IEC/EN 61000-3-2 


Model Selection

As described, users of the LRSA Series can populate the chassis in a manner consistent with their needs. Here are three examples:

  • The LRSA20-12-900 provides one isolated 12 V and 20 A output for a total of 240 W. It does so with only one cassette, an LR2320-9. To achieve this, the LR2320-9’s two 12 V, 10 A outputs are connected in parallel.
  • The LRSA4040-1212-901 provides two separate 12 V outputs at 40 A. It employs four 12 V LR2320-9s, with the four outputs from two connected in parallel for one 12 V, 40 A output. The other two cassettes are connected in the same way to provide the second.
  • The LRSA6048-1215-900 fully populates the LRSA chassis, with three LR2320-9s alongside three LR2540-9s. Connecting all six 12 V, 10 A outputs in parallel results in a 12 V, 60 A output. Similarly, users can build a second output of 15 V at 48 A by paralleling the six 15 V, 8 A outputs. 


Environmental Compliance 

  • The series is RoHS-compliant


Regulatory Notes 

Safety approved to:

  • UL/CSA 62368-1
  • IEC/EN 62368-1 


Physical Considerations

  • The convection-cooled LRSA series operates over ambient and case temperature ranges of -40 to 71 ℃ and -40 to 95 ℃, respectively


Feature image used courtesy of 终有 那天/Unsplash