I posted this in the other thread, but here it is again:
"The alternating current power supply to this switchboard is obtained from the I.C. motor generators which are comprised of either 250-volt d.c. motors and 120-volt a.c. generators, or 120-volt d.c. motors and 120-volt a.c. generators, depending upon the type of installation. The former would take its power directly from the batteries, the latter from the lighting system. If the supply is taken from the lighting system, the installation is also equipped with an emergency supply obtained from a center tap off the battery through a double throw switch, for use in the event of failure of the lighting motor generator set.
The direct current power supply to the switchboard comes from the lighting system. An auxiliary supply of direct current for the gyro compass and torpedo data computer may be obtained from a rectifier which receives its power supply from the alternating current bus.
Fused switches are supplied for the primaries of each of the two 120/8 volt transformers for the 6-8 volt circuits, and for the searchlight. One spare fused switch is provided, wired into the direct current bus, and 2 spare switches are wired into the alternating current bus."
