Can I power controls and fans from internal supply or external power supply? Can I switch between the two?
Most load banks have internal fan and control power and/or external fan and control power. Yes, you can switch between the two via a rotary switch on some portable load bank models. On most permanent load bank models you can switch via a terminal block.
For 3000, 6000, and 8000 SERIES load banks, you will need to use the internal/external supply switch which switches between the two. Please note the internal supply will need to be in the correct voltage and frequency band to work. The power used by the control and fans will be seen on the instrumentation.
For our load bank models, it is recommended for most tests to use the external supply. For more information, please refer to the load bank manual.