Figure 1: Load Box

1 Description

The load box is configured into 3 groups of 5 parallel switched resistors per group. A single switch controls a Resistor in each group simultaneously. Each group is not electrically connected to each other in any way. Each resistor has a rating of 225 watt at 150 ohm. So as you increase the number of switches/resistors in the circuit you are decreasing the resistance which in turn increases the current, power and load. The maximum rms voltage that can be put on this load box is 183Vrms. Use the Fluke 43B on the ohmmeter setting and connect it to one of the groups on the Resistor Load Box. Turn the switches on 1 by 1 while observing how the resistance changes. Try the other groups and such until you understand how the 3 Phase Resistor Load Box operates.