CMS:Power Board

Power Board with the museum main power on

The Power Board manages power used for museum switching equipment. It runs at 48V and usually supplies around 100-180 amps when equipment is running for Sunday tours. In addition to the 48V battery supply, the power board also contains a set of Lorain DC-DC converters which offer 24V, and +/- 130V power for various circuits in the museum. Above the power board is a wooden annunciator that contains lamps which illuminate when the various power systems are in alarm.

History

The power board, or Battery Distributing Fuse Board (BDFB) was originally located in the Parkway central office on Rainier Ave S in Seattle. It was brought to the museum around the same time as our panel switch.

A screencap from a video taken in the 1980s. Included in this lineup are the components that would become the power board as displayed in the museum.

The board has been modified slightly since its removal and subsequent installation at the museum. Aside from installing a plastic cover over the main knife switch, the board has also gained several additions. Notably, the large meters on the upper left and right are from an unknown central office, which were added by museum volunteers. The GM Diesel sign, and large circuit breakers at the bottom right were also museum additions.

Technical Details

The power board in the museum exists in a somewhat smaller configuration than it did while in active service. The core of the power board is the BDFB, or Battery Distributing Fuse Board. Main power (known as office battery) is supplied from the first floor, and brought into a large knife switch on this board. From there, it is distributed to the equipment in the museum.

The board contains several items which are not in active service but are still functional for demonstrations. These items include:

• Two I.T.E. solenoid operated circuit breakers (used to cut off the charging supply from the generators to the batteries in case of overload)
• Motor drive emergency cell switch (used to bring in emergency battery cells in case of excessive load, which could cause the overall voltage to sag)
• Two 4800 amp fuses for the charge and discharge circuits

The board also contains several items that are actively used at the museum, which include:

• The large Weston voltmeter and ammeter in the upper corners of the board
• The main knife switch that powers the museum on and off
• Various distributing cartridge fuses
• Lorain DC-DC converters
• The meter switch, and various voltmeters on the board