Danotherm resistors are used in a wide variety of applications. As such, it is difficult to label them by application. Here, the resistor families are devided in the way of cooling.
It must be noted however, that also the self cooled types can be forced air cooled to improve power capability.
Danotherm power resistors are used as: filter, brake, shunt, snubber, dump, crowbar, charging, de-charging, pre-magnetizing, current limiting, fault detecting, neutral earthing, cabinet heating, de-humidifying, motor starter, ballancing, load bank, voltage dividing, inrush current limiting and ballast resistors and in many other applications.
Number of steps and power rating per step
Type of ventilation: natural convection or forced air
Mounting position: horizontal or vertical (forced air only)
Thermal drift: the difference in ohmic value of the resistor elements between cold and hot condition.
Ingress protection degree, IP20 / IP21 / IP23
Enclosures can be made of galvanized steel DX51D+Z275-M-A-E, mild steel painted in any RAL color or stainless steel types AISI 304 or AISI 316.
Load banks are used for testing equipment such as (emergency) generators and UPS systems or also as dummy loads to maintain the generator at a minimum temperature. Load banks are offered from a few kW up to 10MW and from working voltages of a few hundred volts up to 36kV. Load banks are built from several steel-grid building-blocks making it easy to split up the load bank into (many) smaller loads. Load banks are made for both indoor and outdoor use in IP classes up to IP 23. Higher IP ratings are problematic as it becomes more difficult to dissipate heat.
Brake resistors for Railway applications can be positioned on the roof, under the frame or inside the vehicle in a special compartment. Traction brake resistors are constructed according legislation and international directives. They are always customized and tailored to the ambient conditions such as air temperature, humidity, mechanical forces and dimensions. Test for homologation on vibration, fire and smoke and humidity are performed at external test facilities close to the factory.
TRV resistors are high power, forced air cooled resistors, suitable to be used in harsh environments. Protection degree is IP65 / IP66. The power ranges from 50 – 275 kW. TRV units are fitted with 2 or with 4 strong ventilators to cool the resistor elements. The unit can be as a single resistor group or with multiple groups, in various electrical topologies. Applications are brake resistors on cranes in harbor or deck winches.
CBW resistors consist of a aluminium housing with liquid cooling channels integrated. Inside is the active resistor wire which is incapsulated with sand. CBW resistors combine very high overload capability with liquid cooling. They are ideally suited as high power brake resistors with medium average power. CBW resistors are also used as filter resistors.
WHDN are Danotherms largest, high power resistors. The power ranges from 40-1450kW. They consist of a steel tank with resistor tube elements fitted. The tank is fully welded. Depending on the environmental conditions steel AISI304 or AISI316 is chosen. All WHDN resistors are customized. Water in- and outlet, size of electrical terminals and protection circuits define the design.
WHBS are water cooled, high power resistors. The power ranges from 6-100kW. They consist of a steel tank with resistor tube elements fitted. The tank is fully welded. Depending on the environmental conditions steel AISI304 or AISI316 is chosen. All WHBS resistors are customized. Water in- and outlet, size of electrical terminals and protection circuits define the design.
WHBSA are water cooled, high power resistors. The power ranges from 50-200kW. They consist of a steel tank with resistor tube elements fitted. The tank is fully welded.
This type of resistors is most suited as brake resistor for busses and trucks. For marine applications we recommend to use WHBS or WHDN series.
WHB are water cooled, medium power resistors. The power ranges from 6-23kW. They consist of an aluminium housing with resistor tube elements fitted. It can be fitted with a terminal box or with M6 treaded rods. For marine applications we recommend to use WHBS (fully welded, stainless steel version).
WHHB resistors consist of a aluminium housing with inside the active resistor wire which is directly in contact with the cooling liquid. The cooling liquid must be de-ionised water. Glycol may be added as long as the conductivity of the liquid stays below 2 microS/cm. WHHB resistors are used in high voltage systems, mostly as filters.
Danotherm has developed very flat power resistors for moderate power brake applications in drive systems, braking a few hundreds of watts to few kilowatts during a short time.
The Bi-alpha is available in 3 sizes; Bi-Alpha 4, 5 and 6. Their nominal power is rated at 45W for size 4, 100W for size 5 and 175W for size 6. These values are valid for forced air cooling of 2m/s. By increasing the airspeed the nominal power can be increased. Because of its low profile height they can easily be mounted at the back side of an VFC (Voltage Frequency Converter).
The Bi-Alpha is a simple construction where the resistor wire is wounded on a mica substrate and insulated by mica sheets on both sides. This element is enclosed in a metal alloy housing made from aluminium and zinc. The Bi-Alpha resistors are a cost effective solution for small to medium power drive systems.
Connection leads are insulated with high temperature silicon, rated at 250°C. IP value for each size is IP50.
HSD / HSF are wirewound resistors on mica elements, fitted into a heatsink filled with a silicone rubber which is UL recognized up to a working temperature of 220°C. They are ideally suited as balancing resistors. HSD types have its terminals upwards (vertical) to the heatsink. HSF have its terminals parallel to the heatsink. Its nominal power depends on the heatsink temperature it is mounted on.
HSCC and HSAC are thick film resistors. for optimum cooling they must be mounted on a heatsink. Due to theri very low inductivity, these resistors are ideally suited as snubber or filter resistor in power electronic inverters. HSCC and HSAC are available in 470R and 24kR. Other values are available on request.
HSP resistors are thick film resistors in an aluminium housing. They are intended to be mounted on a heatsink to allow maximum dissipation. Thick film resistors have virtually no inductance and are therefore ideally suited for snubbers in switching circuits. HSP resistors have its connections parallel to the heatsink. HSV have its connections in vertical position. Thick film resistors can be produced with 15%, 3% or 1% tolerance on Ohmic values.
PR resistors are thick film resistors and are offered in two mechanical sizes. PR100 for 100W and PR250 / PR600 for 250 and 600W. These resistors must be mounted on a heatsink of sufficient size to allow the maximum dissipation. Thick film resistors have virtually no inductance. PR types can have a single or a double resistor in one housing. PR250 has optional high voltage connection terminals and can be used in systems with working voltage up to 5 kVAC .
* Heatsink cooled values
These resistors belong to the lower power ratings of the aluminium housed types. They are mostly used in DC-links for charging and de-charging and in small inverter drives systems as brake resistor. CCH can be mounted on a (water) cooled plate to increase the nominal power. The nominal power ranges from 100-570W when cooled by natural air. When mounted on a water cooled plate the nominal power ranges from 500W - 2500W.
Extruded aluminium housing provides superior heat conduction. Housing deep finned for maximum heat dissipation at natural or forced air convection. Gold anodized finish for maximum resistance to environmental conditions. Special thermosetting compound with high thermal conductivity. Winding designed to give maximum core coverage and uniformity for even heat dissipation. Core centerless ground for maximum winding uniformity. Marking at top surface for easy identification after mounting. Complete welded construction terminal to terminal.
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