DC/DC Converters

Schaefer C2500D SERIES DC/DC Converter

The Schaefer C2500D Series Industrial Grade DC/DC Converter provides a reliable and compact solution for industrial power needs. Offering a power rating of 300W to 400W, it supports DC input voltages from 18Vdc to 380Vdc and output voltages from 5Vdc to 220Vdc, with both step-up and step-down configurations available. Designed for flexibility, the C2500D can operate as a stand-alone unit or in parallel-connected systems to support redundancy or increased power capacity. Cooling is achieved through natural convection, ensuring quiet and efficient operation. Flexible mounting options include wall mount, chassis mount, or 19" rackmount via a separate 3U subrack. Optional features such as monitoring, control, and enhanced environmental protection make this series adaptable to demanding environments. Ideal for railway, power utilities (generation, transmission, and distribution), renewable energy, and mining applications, the C2500D Series is engineered for reliability in critical operations.

Features

  • Power Rating: 300W to 400W.
  • DC Input/Output: Input range 18Vdc to 380Vdc; output range 5Vdc to 220Vdc.
  • Cooling: Efficient natural convection cooling across all models.
  • Mounting Options: Wall mount, chassis mount, or 19" rackmount via a 3U subrack.
  • Optional Features: Monitoring, control, mechanical robustness, and enhanced environmental protection.
  • Applications: Designed for railway, power utilities (generation, transmission, and distribution), renewable energy, and mining industries.
Specifications
INPUT
Input voltage DC Input voltage: 10 - 800Vdc
See selection table
Units will turn off with under or over input voltage.
No-load input power 5-6W model (series dependent)
Switch on time 1-2 seconds.
OUTPUT
Output voltage Voltage range; 4.5 - 400Vdc
See selection table
Output current See selection table.
Ripple & noise 1% + 30mVpp
Line regulation 0.1% (±10%)
Load regulation 0.2% typical, load step 10-90%
Load transient 6% typical, load step 10-90%
Response time 2-3ms typical ±1%
Temperature coefficient 0.02% per °C typical.
Holdup time 10mS at 220VAC typical
Turn on rise time 100mS typical (soft start)
Remote sensing Standard for all series
Efficiency 80%-92% typical
Output Options Option dd: Decoupling Diode for redundant / parallel operation
Option cs: Active Current Sharing
Option h: Remote on/off (inhibit)
Option dr: DC OK via relay contacts
PROTECTION
Overload protection Current limited at 105%–110% of full load.
Overvoltage protection OVP switches off module with automatic return to operation
Protection Options Option i: Inrush Current Limiting
Option sd: Reverse polarity protection for DC input by Series Diode
MTBF 100Khrs to 140Khrs at 40°C acc. to MIL-HDBK-217E (notice 1)
ENVIRONMENTAL
Operating temperature -20°C to +75°C (optional -40 to 75C)
Load derating Derate 2.5% per °C, from +55°C to 75°C
Cooling H: Heatsink - natural convection
F: Fan - increased airflow recommended
TF: Temperature controlled Fan included
See selection table
Environment Options Option c: Extended temperature range to -40°C
Storage temperature -40°C to +85°C
Humidity Up to 95% RH, non-condensing
STANDARDS
EMI standards acc. to EN61000-6-4 class A, optionally class B
Immunity standards acc. to EN61000-6-2
C-Tick AS/NZS CISPR11: 2002 Group1 Class A
Safety / Construction acc. to EN60950-1 / EN50178
Protection category IP20 acc. to EN60529 NEMA or others on request
MECHANICAL
Mounting See technical illustrations
Eurocassette, pluggable module for 19" subrack
Option w: Wall Mounting
Option cha: Chassis Mounting
Dimensions See Technical illustration
Connector H15 acc. to DIN 41612 H15 and high current connectors for I > 50A, or terminals / bolts / bars
Mechanical Options Option ms: Increased Mechanical Strength Option t: Tropical protection
19" Rack Mounting Options Subrack Height 3U, 5U, 6U
Wiring, Front Panels Accessories: Fuses, MCBs, Mains on/off switch
Contact Powerbox for rack configuration
Selection Table
INPUT 18-36V OUTPUT AMPS INPUT 36-75V INPUT 45-90V INPUT 80-160V INPUT 160 - 320V INPUT 320 - 380V OUTPUT AMPS COOLING OUTPUT VDC OUTPUT RANGE
C2520 45 C2530 C2540 C2550 C2570 C2580Z 55 H 5 4.5-5.5
C2521 27 C2531 C2541 C2551 C2571 C2581Z 32 H 9 45514
C2522 23 C2532 C2542 C2552 C2572 C2582Z 27 H 12 45609
C2523 20 C2533 C2543 C2553 C2573 C2583Z 23 H 15 14-16
C2524 13 C2534 C2544 C2554 C2574 C2584Z 15 H 24 23-26
C2525 11 C2535 C2545 C2555 C2575 C2585Z 13 H 28 26-30
C2529 6 C2539 C2549 C2559 C2579 C2589Z 7.2 H 48 45-55
C2526 5 C2536 C2546 C2556 C2576 C2586Z 6 H 60 58-68
C2527 2.5 C2537 C2547 C2557 C2577 C2587Z 3 H 110 100-130
C2528 1.3 C2538 C2548 C2558 C2578 C2588Z 1.6 H 220 200-250

Cooling

H: Heatsink - natural convection

F: Fan - increased airflow recommended

TF: Temperature controlled Fan included

See selection table

Model designation options: Add the designation of options to the model number, eg. C2520-dd-dr-cs Options for Input, Output, Environment and Mechanical follow
19" Rack Mounting Options Subrack Height 3U, 5U, 6U Wiring, Front Panels Accessories: Fuses, MCBs, Mains on/off switch Contact Powerbox for rack configuration
INPUT OPTIONS
Option “i” (inrush current limiting): A thermistor is connected in series with the input lines which changes its resistance from high to low when it gets hot. It does not reduce the current surge if the input power is interrupted for a short period of time not allowing the thermistor to cool down. Thermistors are fitted as standard to all mains input models except for 1-phase input of models > 2.5kW. Thermistors are available up to 45A. For higher input current an electronic inrush current limitation can be offered.
Option “ie” electronic inrush current limiting An electronic circuit limits the inrush current.
Option “sd” (series diode): A series diode protects the module against input voltage of wrong polarity (additional power losses).
Option “ad” (anti-parallel diode): To avoid the power losses of a series diode a diode is provided with opposite polarity in parallel to the input blowing an internal or external fuse if the module is connected to a supply with wrong polarity.
Option “au” (auto-ranging) For standard dual AC input models the range of 115/230Vac is to be selected by connecting the input line to different pins on the connector. With auto-ranging the unit senses the input voltage and provides automatically the correct connection.
Option “p” (power fail): A signal (logic or relay) is given if the input voltage (AC or DC) drops below the specified limit. In AC input units we sense the rectified input voltage so that a power fail alarm will not be triggered if at light loads mains power returns before the input capacitors are substantially discharged.
Option “r” (relay): A relay instead of a logic signal is provided for failure indication.
OUTPUT OPTIONS
Option “dd” (decoupling diode): For redundant operation the outputs of two or more units are paralleled behind de-coupling diodes so that an internal fault of one module does not affect the operation of the others. These diodes cause power losses.
Option “cs” (active current sharing): An additional control circuit provides active current sharing via an interconnecting wire between converters that operate in parallel. Active current sharing should be used for multi-output units operating in parallel.
Option “csi” (current sharing interrupt): Option "csi" will effect the removal of the "cs" signal. Should there be an instance where a unit is not supplying the load, then the effect of its "cs" signal is removed, and the load voltage is unaffected by this condition.
Option “h1” (inhibit): A terminal connected to the negative input line also shuts off the converter. This can also be used in conjunction with a thermal trip which shuts the unit down.
Option “h2” (inhibit): Operation of the unit is inhibited if a voltage signal (5V/10mA) is applied in reference to the negative line of the (main) output.
Option “rco” (reducing current limiting at over temperature) A circuit reduces the current limiting level at higher temperature (to be specified).
Option “d” (DC-ok, one output): A logic signal is given if the output voltage (main output in multi-output systems) is below the specified limit.
Option “m” (DC-ok, all outputs): In multi-output systems a logic signal is provided if the voltage of any output is below the specified limit.
Option “ac” (AC ok) A logic signal connected to relay contacts is given if the output voltage of an inverter is below the specified limit.
Option "y" (sys-reset): This logic signal is a combination of power fail and DC-ok as specified for VME systems.
Option "r" (relay): A relay instead of a logic signal is provided for failure indication.
environment options
Option "t" (tropical protection):The unit is given additional protection by a heavy coat of varnish on the printed circuit board(s) and components.
Option "c" (extended temperature range):The circuit is designed and tested for operation at an ambient temperature as low as –40 °C.
Option "ms" (increased mechanical strength): Screws are secured by Locktite and heavy components are fastened by ties and/or glue. Modules with the "ms" option meet the standard EN61373 regarding shock and vibration.
mechanics options
Standard mounting "Eurocassette" pluggable module for 19" sub-racks 8
Option "w" (wall mounting): Module is screwed against a mounting plate for installation in a cabinet. The load connections are typically a terminal block.
Option "cha" (chassis mount) Module is designed for installation to a structure or within cabinet. Screw type connectors are supplied with the module.
Option "din" (DIN rail mount) Module is designed for DIN rail mounting to a structure or within Cabinet. Screw type connectors are supplied with the module.
Technical Illustrations
Downloads
Schaefer_cb2500-AC-DC-PS-BatteryChargers-DC-DC-Converters.pdf
INPUT
Input voltage DC Input voltage: 10 - 800Vdc
See selection table
Units will turn off with under or over input voltage.
No-load input power 5-6W model (series dependent)
Switch on time 1-2 seconds.
OUTPUT
Output voltage Voltage range; 4.5 - 400Vdc
See selection table
Output current See selection table.
Ripple & noise 1% + 30mVpp
Line regulation 0.1% (±10%)
Load regulation 0.2% typical, load step 10-90%
Load transient 6% typical, load step 10-90%
Response time 2-3ms typical ±1%
Temperature coefficient 0.02% per °C typical.
Holdup time 10mS at 220VAC typical
Turn on rise time 100mS typical (soft start)
Remote sensing Standard for all series
Efficiency 80%-92% typical
Output Options Option dd: Decoupling Diode for redundant / parallel operation
Option cs: Active Current Sharing
Option h: Remote on/off (inhibit)
Option dr: DC OK via relay contacts
PROTECTION
Overload protection Current limited at 105%–110% of full load.
Overvoltage protection OVP switches off module with automatic return to operation
Protection Options Option i: Inrush Current Limiting
Option sd: Reverse polarity protection for DC input by Series Diode
MTBF 100Khrs to 140Khrs at 40°C acc. to MIL-HDBK-217E (notice 1)
ENVIRONMENTAL
Operating temperature -20°C to +75°C (optional -40 to 75C)
Load derating Derate 2.5% per °C, from +55°C to 75°C
Cooling H: Heatsink - natural convection
F: Fan - increased airflow recommended
TF: Temperature controlled Fan included
See selection table
Environment Options Option c: Extended temperature range to -40°C
Storage temperature -40°C to +85°C
Humidity Up to 95% RH, non-condensing
STANDARDS
EMI standards acc. to EN61000-6-4 class A, optionally class B
Immunity standards acc. to EN61000-6-2
C-Tick AS/NZS CISPR11: 2002 Group1 Class A
Safety / Construction acc. to EN60950-1 / EN50178
Protection category IP20 acc. to EN60529 NEMA or others on request
MECHANICAL
Mounting See technical illustrations
Eurocassette, pluggable module for 19" subrack
Option w: Wall Mounting
Option cha: Chassis Mounting
Dimensions See Technical illustration
Connector H15 acc. to DIN 41612 H15 and high current connectors for I > 50A, or terminals / bolts / bars
Mechanical Options Option ms: Increased Mechanical Strength Option t: Tropical protection
19" Rack Mounting Options Subrack Height 3U, 5U, 6U
Wiring, Front Panels Accessories: Fuses, MCBs, Mains on/off switch
Contact Powerbox for rack configuration
INPUT 18-36V OUTPUT AMPS INPUT 36-75V INPUT 45-90V INPUT 80-160V INPUT 160 - 320V INPUT 320 - 380V OUTPUT AMPS COOLING OUTPUT VDC OUTPUT RANGE
C2520 45 C2530 C2540 C2550 C2570 C2580Z 55 H 5 4.5-5.5
C2521 27 C2531 C2541 C2551 C2571 C2581Z 32 H 9 45514
C2522 23 C2532 C2542 C2552 C2572 C2582Z 27 H 12 45609
C2523 20 C2533 C2543 C2553 C2573 C2583Z 23 H 15 14-16
C2524 13 C2534 C2544 C2554 C2574 C2584Z 15 H 24 23-26
C2525 11 C2535 C2545 C2555 C2575 C2585Z 13 H 28 26-30
C2529 6 C2539 C2549 C2559 C2579 C2589Z 7.2 H 48 45-55
C2526 5 C2536 C2546 C2556 C2576 C2586Z 6 H 60 58-68
C2527 2.5 C2537 C2547 C2557 C2577 C2587Z 3 H 110 100-130
C2528 1.3 C2538 C2548 C2558 C2578 C2588Z 1.6 H 220 200-250

Cooling

H: Heatsink - natural convection

F: Fan - increased airflow recommended

TF: Temperature controlled Fan included

See selection table

Model designation options: Add the designation of options to the model number, eg. C2520-dd-dr-cs Options for Input, Output, Environment and Mechanical follow
19" Rack Mounting Options Subrack Height 3U, 5U, 6U Wiring, Front Panels Accessories: Fuses, MCBs, Mains on/off switch Contact Powerbox for rack configuration
INPUT OPTIONS
Option “i” (inrush current limiting): A thermistor is connected in series with the input lines which changes its resistance from high to low when it gets hot. It does not reduce the current surge if the input power is interrupted for a short period of time not allowing the thermistor to cool down. Thermistors are fitted as standard to all mains input models except for 1-phase input of models > 2.5kW. Thermistors are available up to 45A. For higher input current an electronic inrush current limitation can be offered.
Option “ie” electronic inrush current limiting An electronic circuit limits the inrush current.
Option “sd” (series diode): A series diode protects the module against input voltage of wrong polarity (additional power losses).
Option “ad” (anti-parallel diode): To avoid the power losses of a series diode a diode is provided with opposite polarity in parallel to the input blowing an internal or external fuse if the module is connected to a supply with wrong polarity.
Option “au” (auto-ranging) For standard dual AC input models the range of 115/230Vac is to be selected by connecting the input line to different pins on the connector. With auto-ranging the unit senses the input voltage and provides automatically the correct connection.
Option “p” (power fail): A signal (logic or relay) is given if the input voltage (AC or DC) drops below the specified limit. In AC input units we sense the rectified input voltage so that a power fail alarm will not be triggered if at light loads mains power returns before the input capacitors are substantially discharged.
Option “r” (relay): A relay instead of a logic signal is provided for failure indication.
OUTPUT OPTIONS
Option “dd” (decoupling diode): For redundant operation the outputs of two or more units are paralleled behind de-coupling diodes so that an internal fault of one module does not affect the operation of the others. These diodes cause power losses.
Option “cs” (active current sharing): An additional control circuit provides active current sharing via an interconnecting wire between converters that operate in parallel. Active current sharing should be used for multi-output units operating in parallel.
Option “csi” (current sharing interrupt): Option "csi" will effect the removal of the "cs" signal. Should there be an instance where a unit is not supplying the load, then the effect of its "cs" signal is removed, and the load voltage is unaffected by this condition.
Option “h1” (inhibit): A terminal connected to the negative input line also shuts off the converter. This can also be used in conjunction with a thermal trip which shuts the unit down.
Option “h2” (inhibit): Operation of the unit is inhibited if a voltage signal (5V/10mA) is applied in reference to the negative line of the (main) output.
Option “rco” (reducing current limiting at over temperature) A circuit reduces the current limiting level at higher temperature (to be specified).
Option “d” (DC-ok, one output): A logic signal is given if the output voltage (main output in multi-output systems) is below the specified limit.
Option “m” (DC-ok, all outputs): In multi-output systems a logic signal is provided if the voltage of any output is below the specified limit.
Option “ac” (AC ok) A logic signal connected to relay contacts is given if the output voltage of an inverter is below the specified limit.
Option "y" (sys-reset): This logic signal is a combination of power fail and DC-ok as specified for VME systems.
Option "r" (relay): A relay instead of a logic signal is provided for failure indication.
environment options
Option "t" (tropical protection):The unit is given additional protection by a heavy coat of varnish on the printed circuit board(s) and components.
Option "c" (extended temperature range):The circuit is designed and tested for operation at an ambient temperature as low as –40 °C.
Option "ms" (increased mechanical strength): Screws are secured by Locktite and heavy components are fastened by ties and/or glue. Modules with the "ms" option meet the standard EN61373 regarding shock and vibration.
mechanics options
Standard mounting "Eurocassette" pluggable module for 19" sub-racks 8
Option "w" (wall mounting): Module is screwed against a mounting plate for installation in a cabinet. The load connections are typically a terminal block.
Option "cha" (chassis mount) Module is designed for installation to a structure or within cabinet. Screw type connectors are supplied with the module.
Option "din" (DIN rail mount) Module is designed for DIN rail mounting to a structure or within Cabinet. Screw type connectors are supplied with the module.
Schaefer_cb2500-AC-DC-PS-BatteryChargers-DC-DC-Converters.pdf

Find the Right Model

Model Number Input Voltage (Vdc) Output Voltage (Vdc) Output Current (A)
product variant C2520 18...36Vdc 5Vdc (Adj. 4.5 - 5.5Vdc) 45A
product variant C2521 18...36Vdc 9Vdc (Adj. 8 - 10Vdc) 27A
product variant C2522 18...36Vdc 12Vdc (Adj. 11 - 13Vdc) 23A
product variant C2523 18...36Vdc 15Vdc (Adj. 14 - 16Vdc) 20A
product variant C2524 18...36Vdc 24Vdc (Adj. 23 - 26Vdc) 13A
product variant C2525 18...36Vdc 28Vdc (Adj. 26 - 30Vdc) 11A
product variant C2529 18...36Vdc 48Vdc (Adj. 45 - 55Vdc) 6A
product variant C2526 18...36Vdc 60Vdc (Adj. 58 - 68Vdc) 5A
product variant C2527 18...36Vdc 110Vdc (Adj. 100 - 130Vdc) 2.5A
product variant C2528 18...36Vdc 220Vdc (Adj. 200 - 250Vdc) 1.3A
product variant C2530 36...75Vdc 5Vdc (Adj. 4.5 - 5.5Vdc) 55A
product variant C2531 36...75Vdc 9Vdc (Adj. 8 - 10Vdc) 32A
product variant C2532 36...75Vdc 12Vdc (Adj. 11 - 13Vdc) 27A
product variant C2533 36...75Vdc 15Vdc (Adj. 14 - 16Vdc) 23A
product variant C2534 36...75Vdc 24Vdc (Adj. 23 - 26Vdc) 15A
product variant C2535 36...75Vdc 28Vdc (Adj. 26 - 30Vdc) 13A
product variant C2539 36...75Vdc 48Vdc (Adj. 45 - 55Vdc) 7.2A
product variant C2536 36...75Vdc 60Vdc (Adj. 58 - 68Vdc) 6A
product variant C2537 36...75Vdc 110Vdc (Adj. 100 - 130Vdc) 3A
product variant C2538 36...75Vdc 220Vdc (Adj. 200 - 250Vdc) 1.6A
product variant C2540 45...90Vdc 5Vdc (Adj. 4.5 - 5.5Vdc) 55A
product variant C2541 45...90Vdc 9Vdc (Adj. 8 - 10Vdc) 32A
product variant C2542 45...90Vdc 12Vdc (Adj. 11 - 13Vdc) 27A
product variant C2543 45...90Vdc 15Vdc (Adj. 14 - 16Vdc) 23A
product variant C2544 45...90Vdc 24Vdc (Adj. 23 - 26Vdc) 15A
product variant C2545 45...90Vdc 28Vdc (Adj. 26 - 30Vdc) 13A
product variant C2549 45...90Vdc 48Vdc (Adj. 45 - 55Vdc) 7.2A
product variant C2546 45...90Vdc 60Vdc (Adj. 58 - 68Vdc) 6A
product variant C2547 45...90Vdc 110Vdc (Adj. 100 - 130Vdc) 3A
product variant C2548 45...90Vdc 220Vdc (Adj. 200 - 250Vdc) 1.6A
product variant C2550 80...160Vdc 5Vdc (Adj. 4.5 - 5.5Vdc) 55A
product variant C2551 80...160Vdc 9Vdc (Adj. 8 - 10Vdc) 32A
product variant C2552 80...160Vdc 12Vdc (Adj. 11 - 13Vdc) 27A
product variant C2553 80...160Vdc 15Vdc (Adj. 14 - 16Vdc) 23A
product variant C2554 80...160Vdc 24Vdc (Adj. 23 - 26Vdc) 15A
product variant C2555 80...160Vdc 28Vdc (Adj. 26 - 30Vdc) 13A
product variant C2559 80...160Vdc 48Vdc (Adj. 45 - 55Vdc) 7.2A
product variant C2556 80...160Vdc 60Vdc (Adj. 58 - 68Vdc) 6A
product variant C2557 80...160Vdc 110Vdc (Adj. 100 - 130Vdc) 3A
product variant C2558 80...160Vdc 220Vdc (Adj. 200 - 250Vdc) 1.6A
product variant C2570 160...320Vdc 5Vdc (Adj. 4.5 - 5.5Vdc) 55A
product variant C2571 160...320Vdc 9Vdc (Adj. 8 - 10Vdc) 32A
product variant C2572 160...320Vdc 12Vdc (Adj. 11 - 13Vdc) 27A
product variant C2573 160...320Vdc 15Vdc (Adj. 14 - 16Vdc) 23A
product variant C2574 160...320Vdc 24Vdc (Adj. 23 - 26Vdc) 15A
product variant C2575 160...320Vdc 28Vdc (Adj. 26 - 30Vdc) 13A
product variant C2579 160...320Vdc 48Vdc (Adj. 45 - 55Vdc) 7.2A
product variant C2576 160...320Vdc 60Vdc (Adj. 58 - 68Vdc) 6A
product variant C2577 160...320Vdc 110Vdc (Adj. 100 - 130Vdc) 3A
product variant C2578 160...320Vdc 220Vdc (Adj. 200 - 250Vdc) 1.6A
product variant C2580Z 320...380Vdc 5Vdc (Adj. 4.5 - 5.5Vdc) 55A
product variant C2581Z 320...380Vdc 9Vdc (Adj. 8 - 10Vdc) 32A
product variant C2582Z 320...380Vdc 12Vdc (Adj. 11 - 13Vdc) 27A
product variant C2583Z 320...380Vdc 15Vdc (Adj. 14 - 16Vdc) 23A
product variant C2584Z 320...380Vdc 24Vdc (Adj. 23 - 26Vdc) 15A
product variant C2585Z 320...380Vdc 28Vdc (Adj. 26 - 30Vdc) 13A
product variant C2589Z 320...380Vdc 48Vdc (Adj. 45 - 55Vdc) 7.2A
product variant C2586Z 320...380Vdc 60Vdc (Adj. 58 - 68Vdc) 6A
product variant C2587Z 320...380Vdc 110Vdc (Adj. 100 - 130Vdc) 3A
product variant C2588Z 320...380Vdc 220Vdc (Adj. 200 - 250Vdc) 1.6A

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