School of the boat 21 Nov 08 (DC Lighting)

[emeacho]

Well, small surprise no one was interested in torpedo tubes.  We only carried those things out of sympathy for the TMs who would be jobless if we took them out.

AS A WARM-UP...

What are the sources of power for DC lighting?

How do you change the source?

Next week, a really hard question!

[Darrin]

Thanks Chief for busting the TM's chops once more, just remember had it not been for us YOU wouldn't have a job

[JTheotonio]

Careful guys - we torpedomen were the only reason these old boats put to sea.  With out us all you would have been doing is minor transport or lifeguard duty.

And without DC lighting, or AC lighting we still could load, lock and fire those big tubes....boom!

[Darrin]

So true my friend, 
but sadly had it not been for the EM's giving us power to the HPAC to pressurize the air banks, we may or maynot have been able to get the power out of the battery to our beloved Hardy/Tines. (personally I think that a TM could have done it for the FUN of it and got it right the first time WITHOUT having to go to their school )

[Mark Sarsfield]

According to Submarine Electrical Installations, Navpers 16162, Chapter 6:

"The starboard emergency lighting system is powered directly through 2 cutout switches connected to the positive and negative end cell terminal connectors of the forward battery. These switches are connected to 13 lighting units, a circuit to the auxiliary gyro, and to the forward and after marker buoy circuits. A branch junction box provides a connection to the gyrocompass control panel for the alarm system.

The port emergency lighting system is directly powered through cutout switches connected to the positive and negative end cell terminal connectors of the after battery. The arrangement of this system is similar to that of the starboard emergency system except for the location of the circuits and the fact that there is no gyrocompass alarm connection.

Each lighting unit consists of two 115-volt lights, a protective resistor, and a snap switch, all connected in series as they always operate directly on full battery voltage."

[emeacho]

Very good Mark.  That's perfect for the DC emergency lighting.  Those cutout switches are located in the battery well and can be opened from deck above (after emergency lighting bus has operators in Crew's Head and forward emergency lighting has operators located in the passageway ner the control room WTD.

What I'd like to know is what are the sources of power for the normal DC ships lighting and where do you switch between these sources?

[Darrin]

To help this block of instruction along and the instructor whom is not at home and working at a famous brewery right now, here is a schematic that you all may enjoy

[emeacho]

Ok, the response to this question was huge!   

To explain the answer the DC lighting system is divided into a port and stbd side.  Each compartment has a DC lighting switch panel (8M or 12M - Refer to Darrin's drawing).  Inside each lighting switch panel there is a port lighting bus and a stbd lighting bus.  Part of the lights in each compartment are powered from the port lighting bus, the others are powered from the stbd lighting bus. 

Now, power to the port and stbd lighting busses comes from the DC Lighting Switchboard (#375), which is located in the forward engine room, port after corner.  The DC lighting switchboard gets its power from either the Forward Aux Power Switchboard (428) and the forward battery, or from the Aft Aux Power Switchboard (408) and the after battery.  There is a Lighting System Battery Selector Switch #66 (After Battery-Off-Forward Battery) located under the DC Lighting Switchboard in the after port corner of FER.   

On the DC lighting switchboard there are two selector switches, one for each of the lighting busses (port and stbd).  Each has Battery-OFF-Shore-OFF positions.  When in BATTERY the power for that lighting bus comes from the either the forward or after battery via its Aux Power Switchboard as selected using the Lighting System Battery Selector Switch.  When in SHORE the lighting bus is powered from a shore power bus that starts in the after engine room (near the after engine room hatch, which is where lighting shore power enters).

So, to summarize:  The sources of power for DC lighting are the forward battery, the after battery, or a shore connection in the after engine room.  The source is changed between forward battery and after battery using the Lighting System Battery Selector Switch #66.  The source is changed between battery and shore power using the selector switches on the DC lighting switchboard. 

All the boats have these panels and if you are powering the original ship's DC lighting, it is important to know where the power comes from.  On Torsk, the DC lighting system is operational.  We have connected 120 VAC into the DC Lighting switchboard at the input from the shore power connection.  The Lighting System Battery Selector Switch #66 is kept in the OFF position so that AC cannot backfeed into the Forward or after Aux Power Switchboards.

Hope tis helps.  I will get Darrin to post a simplified drawing we made of the DC lighting supply.

[emeacho]

Be sure the lighting dimmers are disconnected if you intend to use DC lighting!!!!!  They can overheat and cause a fire.  It was a problem on the boats and can still be if left connected.

[Darrin]

Here's the pic that the Chief needed posted, even gave him directions on how to post a pic here..

[Mark Sarsfield]

Thanks guys.  This is something that is easily doable for those boats that haven't tackled it, yet.

[Darrin]

Well ladies and gentelmen   the question was posted once more about DC power and how much is required to power each component onboard

SO with that being said, i believe it is time to bring this topic back to LIFE once more just like our submarines and see who can help answer the question from Jim on the Batfish

[Mark Sarsfield]

Sounds good.