The DS200SDCIG2A General Electric DC Power Supply and Instrumentation Board serves as an interface to DC2000 drives. It contains several fuses that you can replace if needed with each fuse having an LED indicator associated with it that is lit when the fuse is blown. The fuse functionality is as follows; one fuse is for the 115 V Power Supply, another for the positive signal Power Supply, a third for the negative signal Power Supply, one for the 15 amp NRX assembly and one for the 10 amp NRX assembly.