Without Heatsink: 350 500 750 1100

With Water Cooled Heatsink (40°C): 750 1000 1500 2200

Overload Rating (5s): 4000 5600 8000 12000

Ohmic Value Min (Ohms): 0R5 0R5 0R5 0R5

Max: 10K 18K 27K 27K

Tolerance: ±5% Standard

Maximum Working Voltage (DC/ACrms) Volts: 1500 2500 3500 4000

Insulation Resistance (Volts): >=10000 MΩ

Dielectric Strength (AC peak) Volts: 4500 standard and 6000 special

Inductance (Henries): 5-50 µH at 7-70 µH at 10-100 µH at 20-200 µH at

Weight (g): 460 670 920 1250

Heat Dissipation: Although the use of proprietary heat sinks with lower thermal

resistance is acceptable, up rating is not recommended.

The use of proprietary heat sink compound to improve

thermal conductivity is essential.

Power rating. The dissipation power of a resistor depends also from the mounting position. If the resistor

is mounted onto a surface, the latter takes part positively (if it is large and conductive) or

negatively (if it is small and insulating) to the thermal dissipation.

Data of power rating are referred to a resistor mounted vertically, with terminals in the lower side and

away from the nearest surface at least 10cm, in order to avoid thermal influence from the wall.

will be mounted upright. The length of the heat sink shall be at least 40 mm longer than the resistor’s

body (20 mm for each side).

Power rating of a resistor mounted on a water-cooled heat sink. If the heat sink is water-cooled,

power dissipation increases considerably, and the limiting power rating is due to temperature of the

resistor body. In the case illustrated in the specifications board, the temperature of the heat sink is 40°C

and the resistor’s surface reaches 300°C. In this case too, the length of the heat sink shall be at least

20 mm longer than the resistor’s body.

Absorbed energy @ 250°C ΔT. It represents the quantity of energy stored into the resistor when it

has reached 250°C of temperature rise. The above indication is an index of the thermal capacity of

the resistor.

- QJ is the quantity of energy expressed in Joule, - Cs is the specific heat of the employed resistance alloy

expressed in °K, reached by the wire during the impulse.

As type and quantity of wire are characteristics of every resistance value and resistor model, the

acceptable temperature limit of wire is relevant.

This limit (@ 25°C) is:

- 500°C for the standard operations (steady state load);

- 800°C for not repeatable overload.

The following graphs show these two conditions for each resistance value and resistor type.