Ohmite TAP1000W/2000W Heat Sinkable Planar Resistors

Ohmite TAP1000W/2000W Heat Sinkable Planar Resistors deliver 1000W/2000W of continuous power at 125°C bottom case temperature. The TAP1000W/2000W resistors feature a high energy rating, low inductance, a resistor element that is electrically isolated, high dielectric strength, and a small footprint. The design creates a constant pressure to the cooling plate of approximately 300N for proper thermal flow. These resistors are ideal for variable speed drives, power supplies, control devices, robotics, motor control, and other power designs.

Heat-sink Application Note

The TAP resistors require proper heat sinking techniques for good performance. Please follow these guidelines when designing a TAP system:

• Heats sink plate (base plate of the resistor) temperature must be monitored to establish proper de-rating. The best technique is to attach a thermocouple to the side of the base plate of the resistor. The temperature of the plastic housing or heat sink cannot be used to establish the rating of the resistor. Usage of laser thermometers should be avoided.

• To obtain a power rating of 1000W or 2000W, the bottom case temperature must not exceed 85°C. This can only be achieved if the thermal conduction to the heatsink R_th-cs<0.025°K/W. This value can be reached by using a thermal transfer compound with a heat conductivity of 1W/mK. The flatness of the cooling plate must be better than 0.05mm overall. The roughness of the surface should not exceed 6.4µm.

• Due to very high power density, only liquid-cooled heat sinks are recommended for applications when greater than 300W power rating is desired.

• A properly designed heat sink should have more than 2 cooling pipes under the surface of the TAP resistor.

Specifications

Electrical specifications:
- 1000W or 2000W at 85°C mounting plate power rating
- 0.5Ω to 1000Ω resistance range
- +10% standard resistance tolerance
- 2000V_DC operating voltage (maximum)
- ± 250 PPM/°C temperature coefficient
- 6KV standard dielectric strength
- -55°C to 85°C operating temperature range

Material specifications:
- Thick film on Alumina substrate resistor element
Case specifications:
- #10-32 terminal screws
- 10 in-lb contacts torque (maximum)
- #8-32 mounting screws
- 15 in-lb mounting torque (maximum)
- 50mm ± 1mm (minimum) creepage distance