Touch-safe PTC Fan Heater
CSF 028 | 250 W, 400 W

  • Compact size
  • Integrated pre-set thermostat
  • Quiet operation
  • Heating power adjusts to ambient temperature
  • DIN rail or screw tab mount available

The CSF 028 fan heater prevents formation of condensation and provides evenly distributed interior air temperature in enclosures.  The touch-safe plastic housing and the small size makes it ideal for use in enclosures with a high packing density.  The heater is equipped with a fixed set point thermostat and is easily wired via external pressure clamps. Two different mounting options are available - DIN rail or screw tabs. The robust screw tab mounting is particularly suitable for applications with high vibration.

Heating elementPTC resistor, temperature limiting
Overheat protectionbuilt-in temperature limiter
Axial fan, ball bearingservice life 40,000 h at 104 °F (40 °C)
Axial fan, free blowing

32 cfm (54 m³/h) @ AC 120 V

26 cfm (45 m³/h) @ AC 230 V

Connection2-pole dual pressure clamp for solid wire AWG 14 max. (2.5 mm²),
stranded wire (with wire end ferrule) AWG 16 max. (1.5 mm²)
Housingplastic according to UL 94V-0, black
Mountingclip for 35 mm DIN rail, EN 60715 or screw mount (Ø 5.5 mm),
clamping torque 2 Nm max., washers must be used
Mounting positionvertical airflow (air outlet up)
Dimensionsmodels with DIN clip: 4.13 x 3.35 x 4.65" (105 x 85 x 118 mm),
models w/ screw tabs: 4.13 x 4.53 x 4.25" (105 x 115 x 108 mm)
Weight17.6 oz. (500 g)
Operating / Storage temperature-40 to +158 °F (-40 to +70 °C) / -49 to +158 °F (-45 to +70 °C)
Operating/Storage humiditymax. 90 %RH (non-condensing)
Protection class / Protection typeII (double insulated) / IP20

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Part No.
DIN mount
Part No.
screw tab mount
Operating voltageHeating capacity¹Inrush current max.Recommended
pre-fuse T
Switch-off temperature²Switch-on temperature²     Approvals

02821.9-0602821.9-08AC 120 V, 50/60 Hz250 W6.0 A10.0 A59 °F (15 °C)41 °F (5 °C)UL File No. E234324  -EAC
02821.9-0902821.9-11AC 120 V, 50/60 Hz250 W6.0 A10.0 A77 °F (25 °C)59 °F (15 °C)UL File No. E234324  -EAC
02820.9-0602820.9-08AC 120 V, 50/60 Hz400 W9.0 A10.0 A59 °F (15 °C)41 °F (5 °C)UL File No. E234324  -EAC
02820.9-0902820.9-11AC 120 V, 50/60 Hz400 W9.0 A10.0 A77 °F (25 °C)59 °F (15 °C)UL File No. E234324   -EAC
02821.0-0602821.0-08AC 230 V, 50/60 Hz250 W9.0 A10.0 A59 °F (15 °C)41 °F (5 °C)ULVDEEAC
02821.0-0902821.0-11AC 230 V, 50/60 Hz250 W9.0 A10.0 A77 °F (25 °C)59 °F (15 °C)UL VDEEAC
02820.0-0602820.0-08AC 230 V, 50/60 Hz400 W15.0 A16.0 A59 °F (15 °C)41 °F (5 °C)ULVDEEAC
02820.0-0902820.0-11AC 230 V, 50/60 Hz400 W15.0 A16.0 A77 °F (25 °C)59 °F (15 °C)UL VDEEAC

¹ at 68 °F (20 °C) ambient temperature; ² tolerance of ±5 K
Note: Other Switch-off and Switch-on temperatures on request.

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Air guide for improved heat distribution

The air guide is an accessory part for use with the fan heater CSF 028. It can easily be clipped onto the protective grill of the fan heater without use of any tools, and diverts the exiting warm air by 45°. This results in an overall improved heat distribution within an enclosure or cabinet. The temperature above the protective grill is reduced by up to 68 °F/20 °C (measured approx. 3.9”/100 mm above protective grill) and may make the use of custom heat ducts obsolete.



Part No. Dimensions²Plastic1 Packing unitWeight (approx.)
2520173.3 x 3.3 x 0.5“ (85 x 85 x 12 mm)UL 94V-0, black1 piece1.2 oz. (35 g)

² Dimensions when mounted on fan heater.

Air guide Part No. 252017
Fan heater with air guide

Dimensioned Drawings - DIN rail mount

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Screw mount