NEED WIRING HELP

Tony,

First, welcome to OGR.  You will find many helpful and knowledgeable folks here willing to assist you with any issues you have.  Judging by your first post, you need help.

Regrettably, I cannot help you with the technical issues.

I can, however, suggest that you edit your original post and make it more readable by using capitalization and punctuation for those members who have, and can supply, the technical assistance you apparently seek.  It is often challenging to read a post seeking help without making it more difficult reading with the absence of capitalization and punctuation.

Again, welcome to OGR.

I'm sure I'll be corrected if I'm mistaken as I don't use the SC2 and am only going off the manual and my memory of how it works here.  That said here's my thoughts.  

The separate power supply requirement is a bit confusing, and I'm unsure of the reasoning behind this, but I'll assume there is a good reason for it besides just providing adequate power to track and accessories.  My best guess is that many accessories don't like to be powered off 18VAC and will operate better on 12-14VAC.  

When it comes to supplying power to actually supply the SC2, as you noted for switches the sc2 will get power from the switch, specifically the one connected to SW1.  When controlling only accessories, you need to supply power either from the wall pack that should have come with the sc2, or you can use track power or an accessory transformer connected to the power terminals on the sc2 located to the left of the terminals for SW2.  

For the actual switching the SC2 uses relays.  If I recall they are wired so that each block of 3 terminals has two relays attached with the middle terminal common between both relays.  I think each relay is rated for 10 amps on the SC2.  

As far as I can tell it shouldn't matter if you run the 'hot' or the 'common' through the SC2's relays, as long as you stick with one or the other on any set of three terminals. It would probably be good practice to stick with one or the other throughout your layout.  

JGL 

TONY_BBC posted:

i have a 14x8 LIONEL o gauge layout with 3 interconnected loops and a few spurs. Power is from 2 180 watt powerhouse power supplies via 3 (one for each loop) tmcc track power controllers.  Currently they feed 2 block power controllers but i hope to wire them out of the loop as i no longer run old non-tmcc/legacy engines.

i am using both the original tmcc controller tied together with the legacy controller.

my question is how to wire the sc-2 switch and accessory controller.

i use an old type "R" transformer to supply power directly to all 15 switches. I am using the 16-24v scale for both knobs thus i ground the terminal common to both knobs to the outside rails of the layout which i must do because 031 switches require track ground.  I have 4 SC-2. I have wired 3 with at least 4 switches. Thus the devices are now powered by switch power from the "R" transformer.

I dont understand how to wire the fourth one for accessories only. The manual indicates that the switches and accessories must be  powered by separate power supplies not used to power the track.

i want the second knob of the "r" transformer to power the accessories.

1) by grounding the "R" transformer to the track thus having a common ground between the legacy/tmcc system providing track power and the power going to the switches and accessories have i violated the requirement of independent power sources the sc2 manual requires. Is it ok to have the power source for the switches and for accessories be the same transformer with a common ground to the legacy system and not violate the manual requirement of ndependant sources.

2) are the 6 sets of 3 terminals independent from the electronics of the sc2 like the terminals of a relay are not electrically connected to the power that throws the relay. 

3) the manual shows all accessories having positive power going to each accessory and then leaving it on the ground side when it then goes thru either the on/off side or the momentary side of each set of 3 terminals on the SC2 with the middle terminal going back to the power source.  Can i run the positive side thru the sc2 then go to the accessory and then run the accessory ground to the track ground since the second knob is also grounded to the track ground via the process of grounding the switches.  If i can do that will it blow out the sc2 electronics as those electronics must be connected to sw1 which powers it when using switches. Being able to do that will save a lot of wiring.  Are all 6 sets of terminals tied to the sc2 electronics and can i avoid damaging it yet running positive power thru the other 5 sets avoiding the first set.

4) assuming i can run pos power thru the cs2 terminals can i do that on the 3 sc2 that are powered by switch power as they control 4 switches each thus leaving me 5&6 for accessories.

5) i assume i can power the accessory sc2 with track power as indicated n the manual

bottom line is can i have a common ground for sc2 power, accessory power, switch power, track power and legacy system power.  Can i save wiring by switching positive side instead of gnd side and ground all accessories to track ground and save lots of wiring as i can run one power line to the sc2 and distribute power via sets of terminals to the accessories which will require only one long wire and ground each locally to nearest track.

is this safe for the sc2's

tony

Well, a lot going on here - There are two Lionel videos that may help guide you-

SC2 for Switches

SC2 for Accessories

But, I do have one question - Do you have the power supply that is included with the SC-2?

The other trick if you get stuck on the common feeding back, bridging or causing issues may be to modify it as one has to do for FasTrack. The ground trace is cut that leads from the AUX in terminal to separate the track common from the SC2 common.

I only use these in a Legacy environment, so I can't help much more. I can tell you as a noob, I had all kinds of power issues until I cut that ground/common trace and used the included power supply with the barrel jack.

That provides a remotely controlled set of relays that I can use to switch anything without concerns of power issues.

I dont think i got power supplies with the sc2 or I misplaced them. Plan to use track power.

i use sc2 in legacy also.

i dont understand your explanation on common / ground. What am i cutting?

tony

TONY_BBC posted:

i dont understand your explanation on common / ground. What am i cutting?

Cut this trace from the #1 block to the aux power block:

The SC-2 now cannot be powered by a switch connected to #1, only by wall-wart or external/aux transformer power(fixed voltage, 7-20 volts, any AC power - used with acc/switches/trains is OK, it doesn't matter now that the trace is cut). However, now the statement in the manual "Each of the SC-2’s ground terminals are independent of all other ground terminals" is really relevant as now each of the 6 blocks may be used to switch anything you want - ground or power connection to switches or accessories.

This modification is actually necessary if using all FasTrack non-command remote switches on each SC-2 as the switches do not pass enough current through them to power the SC-2.

The only problem is i dont see a wire going from the terminal block for sc2 power to sw1.

do you have to open it up to see the wire

tony

Also if its only one wire then the ground of each set of terminals or at least sw1 terminals and the power terminal going to the electronics are connected.

if must open it how do i do that

tony

Yes, you need to open it, and it's not a wire... it's a printed circuit board conductive track or "trace". There are 4 screws on the back of the SC-2.

TONY_BBC posted:

Also if its only one wire then the ground of each set of terminals or at least sw1 terminals and the power terminal going to the electronics are connected.

Just  SW1 - correct. A switch must be connected to SW1 to power the SC-2... cutting the trace makes it independent of the power supply at aux or wall wart connections, requiring using one of these two options to power the RF, logic operations, & relay solenoids of the SC-2.