New to DCC, I am building a new 4x8 N scale layout, one user, up to 3 locomotives. Will be mostly mainline with one yard and a couple of spurs. Advice on whether I need to make electrical blocks and how many? Thanks.
You may or may not be confused between power blocks and electrical blocks.
A power block has it’s own input and keeps running is there is a short in another power block. If you had an around the room empire requiring multiple operators, you would want multiple power blocks.
There are three reasons to have electrical blocks in DCC
- Some low end sound decoders automatically start up when you power up the layout. AFAIK you can’t change CV’s to stop that. It’s annoying.
- There is a concern that if you have enough locos, they could put a power drain on a starter system to max out the power output even though they are parked on sidings.
- It makes shorts easier to isolate. In a 4x8 layout I think that value is pretty dubious. If you are a lone wolf, you know the short occured where your loco ran through an improperly set switch.
I agree that such a small area probably does not need blocks.
One side discussion we’ve had in a number of threads concerns the real need to break up large layouts into blocks when there is a lot of power available, to limit the power in any single block to prevent damage. A large layout with perhaps 8 amps of power would be better subdivided with breakers limited to 2 or 3 amps each so that full 8 amps wouldn’t be crossing through a short and causing damage.
Henry and Mr. B. have already given you some good information.
Let me add a thought or two.
A power block, protected by its own circuit breaker, is called a power district in DCC. A separate power district will isolate that section of track from the rest of the layout. Any short that occurs inside the power district will not affect any track outside of the power district.
So, while your layout is small, controlled by a single operator, you could turn the yard into its own power district. That way, a short in the yard will not stop operation of your mainline.
Rich
It can be handy to have an off switch to cut power to a siding or two in order to park a locomotive. For mainline you only need power districts for large layouts or for the three aspects noted above.
I need to do that. Can anyone recommend some economical switches to cut power to DCC blocks?
I just use old school Atlas Connectors.
https://shop.atlasrr.com/p-4779-connector.aspx
Keep in mind you will still need to isolate any reverse loops you have, and you might want to think about setting up blocks now when laying track in regards to someday adding signalling with track detection circuitry.
You can also use a DPDT switch to set up one electrically isolated block of track to use as a programming track. It can be nice to be able to test run an engine, then change a CV and test it some more, without having to keep picking it up and moving it to an off-the-layout programming track.
I would think a DPST would work for killing the DCC power/signal to a block, such as a staging yard block. Maybe a DPDT could be useful for isolating a track for programming.
The Atlas Connector switch panels (yellow switch buttons) give you three switches in one panel. These are simple on/off switches for one power wire which is all you need to kill a DCC or DC siding. For clarity, switching off only one rail is sufficient. For simplicity I always switch off the same rail. That’s how the Atlas Connector switch works. It’s designed to sort how off the same rail on up to three sidings
Optionally, in the Atlas Connector switch the other “polarity” flows directly and unswitched through the same switch panel, if you wish to do so.
These switches also connect conveniently edge to edge if you want more than three off switches.
I would suggest to get a switch that feels correct to you. Any single pole single throw (SPST) switch will work. You just need to turn off one rail.
I prefer full sized industrial toggles just because of the tactile feel they have.
The cost is minimal for just a few switches, so buy what feels right to you.
-Kevin
Richhotrains has a thead about getting rid of his switches for tortoises. Check it out and pm Rich
Those switches that I have are DPDT toggle switches. There is no point in sending me a PM because my PM feature hasn’t worked in two months thanks to the indifference of Kalmbach who ignores my emails and pleas for help.
Rich