Wirewound on ceramic core coated with cement, filled with quarzite sand and sealed with silicone plug
The RFH is a resistance realized within a finned dissipater with wire wound on a ceramic support coated with inorganic phosphate cement. The dissipater is filled with silica sand and sealed with a silicone elastomer and an aluminium cap. Versions purchased on the website are 3: the RFH 1PG features the output of the two cables from a single gland, the RFH 2PG through two cable glands. The two versions differ in the degree of IP protection (IP55 in the first case and IP65 in the second case) and by the value of maximum operating voltage. The resistance with thermal pad for version RFH 1PG can be purchased on the website: RFHT 1PG.
The main areas of application are industrial automation, energy and railway sector.
For what types of applications is it used?
The product is used: as a dynamic terminating resistor, as a basic element in harmonic filter circuits as a charge and discharge capacitor resistance in RC circuits, as a protection resistance for short lasting overcharging.
The RFH family has 2 models with nominal power between 500W and 700W and ohmic value between 3.3 Ω and 51k Ω. Maximum operating voltage is 1000 V for version RFH 1PG and 2000 V for version RFH 2PG.
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 on page 3 of the data sheet shows the relationship between the temperature on the casing and the power applied for a heating element placed horizontally.
The resistance can be installed horizontally or vertically, in this case it is necessary that the cables are facing downwards. For mounting use the 4 holes available. The provided cables that have not been stripped are used for electrical connection. There is also a M6 bushing for the earth connection. The dissipater provided is not anodized. The flat shape of this resistance makes it particularly easy to fit into electrical panels.