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RFK/S 800 – A

Cross Reference

RFK/S 800 – A

Wire wound on mica plate coated with cement filled with quarzite sand and sealed with aluminum plug

The RFK is a wire resistance wound on a mica cement coated plate, immersed in quartzite sand and placed in an anodized aluminium casing. Sealing is carried out using silicone elastomer and aluminium cap. RFK/S models 600 and 800 are particularly suitable for the railway sector and have an IP67 degree of protection.

Overview Table

Min Resistance
Max Resistance
Tolerance (%)
Rated Continuos Power (W)
Protection Degree (IP)
Not Inductive
Rated insulation voltage (V)
(Clarification on Voltage definitions.pdf)
Thermal switch

These options are available for this product:*

ohmic values out of range, special tolerance on resistance special cables, different cable lenght. *Options must be ordered separately. Contact Fairfild directly.
*Options must be ordered separately. Contact Fairfild directly.

In what sectors is this resistance used?

The main areas of application is rolling stock.

For what types of applications is it used?

The product is used: as a charge and discharge capacitor resistance in RC circuits and overvoltage protection.

What are the electrical specifications?

The RFK/S family has 4 models with power ratings from 220 W to 275 W and the ohmic value ranges between 0.5 Ω and 390K Ω. The maximum operating voltage is 1800 V for version A and 3000 V for version B.

What are the overload conditions?

The resistance can be overloaded with respect to its nominal power based on the working cycle (insertion and rest time). For duration pulse less than one second, the overload permissible also depends on the ohmic value. For pulses of longer duration, the internal quartzite plays a decisive role in dissipating energy. See the section on overloads in the data sheet.

What is the temperature of the resistance?

The temperature of the resistance depends on the power that it will dissipate. Numerous factors influence the dissipation capacity; please consult our technical data sheet for detailed information. The graph of the data sheet shows the relationship between the temperature on the casing and the power applied for a heating element placed horizontally.
The component may be mounted both in vertical or horizontal position. When mounted in the vertical orientation, the terminals must not be positioned at the top. The unit must be fixed with 2 screws M6 with tightening torque of 8 Nm. A minimum of 150 mm of free space must be provided in all direction around the resistor.
DOWNLOAD Clearance around RFK Rev.03_Public


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