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PB315 SERIES PB315 - DC/DC Rolling Stock Converter

  • 250W and 500W DC/DC converters for railway
  • 45-154Vdc input to supply 24Vdc 20.8A or 10.4A
  • Natural convection cooling with integral heatsink
  • High resistance to pollution
  • Wide input voltage range
  • High efficiency low thermal stress
  • Different input/output connectors
  • Input polarity reversal protection
  • High tolerance of input ripple
  • Input inrush current limiting
  • Input overvoltage lockout
  • Output overload protection
  • Output overvoltage protection

PB315 -  DC/DC Rolling Stock Converter

Product Overview



500W  45-154Vdc / 24Vdc Converter for Railway Rolling Stock Applications 

PB315-24 Series:   Is a family of 500W and 250W DC/DC converter design for rolling stock, railway applications.  These converters operate from a 45-154Vdc input and supply a 24Vdc/20.8A or 24Vdc/10.4A output.

Natural convection with integral heatsink:  Model PB315-24*-H  (where  * = input/output terminal code) employs an integral heatsink and nartural convection cooling.  No additional heatsinking such as a cool plate is required.  In free air conditions, this model is rated to 500W, output power at ambient temperatures up to 50C.  The model PB315-24* does not include the integral heatsink.  In free air conditions, this variant is rated to 250W output power at ambient temperatures up to 45C.

High resistance to pollution:   Has an enclosed chassis with no air ventilation holes.  It has no cooling fans.  Also, the internal printed circuit boards are conformally coated.  As a result, it has high resistance to contamination by dust or other pollutants.

Wide input voltage range:   The PB315-24 are designed to operate from a 72Vdc, 96Vdc or 110Vdc supply from an accumulator battery as defined by EN50155:1996. It operates continuously from an input voltage of 45-154Vdc. This wide input voltage range allows a single model to be used on many different rolling-stock power sources. It also allows the unit to provide stable output voltage even with large dips in the input supply voltage, as can occur during locomotive engine starting.

High efficiency and low thermal stress   Has a typical full load efficiency of 90% and employs substantial heatsinking. Consequently, thermal stresses on power-dissipating components are low leading to high reliability and long life.

Five different styles of input/output terminals:   Can be fitted with screw terminals (S), cage clamp terminals(C), 6.4mm Faston terminals (F), a pluggable screw terminal block with screw flanges (P), or a circular MIL connector (M)

Input polarity reversal protection and high tolerance of input ripple:   A high voltage diode is included in series with the input to the unit. This diode prevents damage to the unit if input polarity is accidently reversed. It also allows the PB315-24 series to be supplied from a DC source with a large amount of AC ripple (15%) without stressing the input filtering components.

Input inrush current limiting:   Input inrush current is limited to a max of 25A at input voltage of 110Vdc. This inrush changes proportionally to the applied input voltage. Inrush current limiting prevents contact welding of circuit breakers or nuisance blowing of fuses supplying input power to the PB315-24

Input voltage lockout:   The PB315-24 will shut down if input voltage exceeds the permitted value.

Output overload protection:   The PB315-24 maintains constant output voltage up to the set current limit. After the current limit is exceeded the converter switches to constant output current mode. The constant current mode extends to short circuit on the output. There is no limit on the maximum load capacitance or overload duration apart from thermal limitations.

Output voltage droop sharing:   The output voltage of the PB315-24 series measured on the main output before the redundancy diode decreases linearly by between 1.0% and 1.5% from no load to full load. This voltage droop assists current sharing between multiple parallel-connected PB314-24 units


Input voltage


Complies with power supplied from an accumulator battery with the nominal voltage of 72Vdc, 96Vdc, or 110Vdc as per EN50155:1996

Input current 15A
Inrush Current 25A at 110Vdc input
DC ripple factor 15% (EN50155 cl.
Output Voltage 24Vdc (23.76 - 24.24V)
Output Current

PB315-24*-H: 20.8A

PB315-24*: 10.4A

Continuous power

PB315-24*-H: 500W

PB315-24*: 250W

See derating curve

Ripple voltage 100mV p-p
Line regulation 0.5% at full load
Load regulation

1.13Typ (1.0-1.5) %Vnom. 0% to full load

measured before redundancy diode

Efficiency 90% at full load
Power dissipated

PB315-24*-H: 55W at full load

PB315-24*: 27.5W

Redundancy diode

0.33 (0.2 - 0.7) Vdc

Hold up time

See technical illustration

Operating Ambient Temperature See technical illustrations

Natural convection

No cold plate required

Relative Humidity

5% - 90%

Non condensing

Degree of Pollution

PD3 (Per IEC60077-1)


Designed to comply with EN50121-3-2:2000 and EN50155:1996

Conducted Emissions

(Input and Output)

150kHz-500kHz: 99dBuV QP

500kHz-30MHz: 93dBuV QP

Radiated Emissions

30MHz-230MHz: 40dBuV/m QP @ 10m

230MHz-1HHz: 47dBuV/m QP @ 10m

Fast Transient

Burst Immunity

2KV 5/50nS Tr/Th

5KHz rep frequency

Surge Immunity

Input only per EN50155

Direct Transients

1.8KV waveform 5/50us

Source impedance 100ohm

Conducted Radio

Frequency Immunity

3Vrms carrier

150KHz to 80MHz

1KHz , 80% AM

Source impedance 150ohm

Variations & Interruptions

of voltage supply

Input only per EN50155

Unit complies with 45Vdc to 154Vdc

(0.6 x 72V to 1.4 x 110V)

operation continously

Class S1: No interruptions

Radio Frequency Immunity

10V/Mrms carrier

80MHz to 1 GHz

1KHz 80% AM

Electrostatic Discharge

6KV contact discharge

8KV air discharge

. .
Input reverse polarity Indefinite, series diode on input.
Input fusing

15A, 500V (T) HRC ceramic

32 x 6.3mm fuse - internal

Input overvoltage


Approx 160Vdc, Auto recovery.
High input ripple Indefinate. Series diode on input.
Output short circuit

PB315-24*-H: 24Vdc 33A

PB315-24*: 12Vdc 16.5A

Indefinite. Auto recovery

Output overcurrent

(Current limit)

PB315-24*-H: 24Vdc 31A

PB315-24*: 12Vdc 15.5A

Auto recovery on removal of over current

Output overvoltage



Input power must be cycled off then on to restart

Over temperature

110C internal temperature.

Auto restart after cooling down


Input to Chassis: 2121Vdc

Input to Output: 4242Vdc

Input to Output (M input connector): 3960Vdc

Output to Chassis: 707Vdc

Rated Insulation voltage

Input: 154Vdc

Output: 25Vdc

per IEC60077-1

Rated Impulse

withstand voltage

Input: 2.5KV

Output: 0.8KV

per IEC60077-1

Overvoltage Category

Input and Output: OV2

per IEC60077-1


Input Output

Terminal Code: *

PB315-24 * (-H)
Input and Output: S

5 way screw T/B 40A/600V

suitable for M4 ring lugs.

Input and Output: C

7 way cage clamp T/B 20A/300V

suitable for 4mm2 wire

Input and Output: F

10 way 6.4mm male QC faston terminals

Input and Output: P

Phoenix contact pn DFK-PC-15/5-STF-10,16 or similar 5W feed through terminal block with screw flanges

Mating connector: Phoenix contact pn PC 6/5-STF-10,16 or equivalent 5W pluggable screw terminal block with screw flanges suitable for 6mm2 wire supplied with unit.

Input and Output: M

MS3102E24-22P F80 panel mounted plug. 4 x #8AWG crimp contacts.

MS service rating D

Mating connector: MS3106E24-22S F80 straight receptacle, supplied with unit.

Ground Terminal

M5 x 12mm stud


Option L: Green LED mounted on top cover.

ON when output voltage is present

General Chassis mount enclosure suitable for standalone use
Mechanical Outline

L: 321.5L, W: 150mm

H: S=86, F=87, H=104mm (without mating connector)

Mounting Centres

305mm x 100mm

Suitable for 4 x M6 hardware

Protection Degree IP40 as per AS1939

2.5 kg


Technical Illustration

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