Common Neutral Power Snakes

[AJDEJR]

Has anyone made and ran a multi conductor power snake (cable) from a controller to their fixtures?

I have one controller that will be running stuff on my roof AND on the ground but do NOT wait to run multiple extension cords to everything!  I was thinking about creating a multi conductor power snake to be able to run just ONE cable to the roof from the controller that has multiple plugs but the only thing that will be separate is the 'HOTS or X' while all Y's are tied together and G's are tied together!

[Tim Fischer]

This can be done, if you know what you're doing.

Most importantly you need to understand that the common neutral needs to be sized to handle the total current of all the shared channels.  So if you have 8 channels sharing a neutral, and have a 2A max load on each channel, your common neutral will see 16A.

Secondly, you never want to share a neutral across circuits.  That is, if you have one controller plugged into 2 outlets, don't share a neutral between halves of the board.  GFCI's hate that and in any case it's bad practice.

Finally, you need to be 100% sure that your outlets and controllers are wired properly, with the neutrals on the wide prong and the hots are on the smaller plug.  If not, you can easily have a situation where you have a suicide plug (a male plug with a hot prong).

-Tim

[Ken Benedict]

Don't combine the neutrals; it will create problems.

 

Run extra extension cords. This will be safe and will allow you to reconfigure your layout when things change.

[Godney]

Yes you can combine the neutrals, but remember what Tim said in the previous post that the neutral must be larger to handle the load of  all the channels you have on the circuits involved. And by the way i have been using shared neutrals on my system of 46000 lights and 48 channels of LOR andHAVE NEVER HAD A PROBLEM.

Edited January 19, 2014 by Godney

[Ken Benedict]

Yes you can combine the neutrals, but remember what Tim said in the previous post that the neutral must be larger to handle the load of  all the channels you have on the circuits involved. And by the way i have been using shared neutrals on my system of 46000 lights and 48 channels of LOR andHAVE NEVER HAD A PROBLEM.

 

On which side of the LOR Controller? Power input or Power output?

[Tim Fischer]

On which side of the LOR Controller? Power input or Power output?

 

My reply was not theoretical, I've been using them for over 10 years on parts of my display (between the controller and the lights).  If you don't know what you're doing, you can really get into trouble, but if you do, it works perfectly.

 

-Tim

Edited January 20, 2014 by Tim Fischer

[plasmadrive]

I think you will find that Ken's question is very valid.  If you did a single neutral on the out going side that is no big deal as there is a single neutral coming in and the load is split among the output channels.  However, if you try to use a common neutral on the incoming side along with two incoming power phases, unless those two phases are opposite each other, (L1 & L2) you must have a neutral that is sized to handle both of the amp ratings combined.  (not possible with GFIs however).

 

When you have opposite phases with a common neutral, the neutral carries only the imbalance of current between the phases.  Not so if the "hot legs" are of the same phase.  In that case the neutral must carry the load from both breakers. 

 

As someone mentioned earlier in the thread, GFI's don't play well with this sort of setup unless you get one that is specifically made for this type of power setup.  Something like what they use for spas and such.

 

Like Tim said, if you know what you are doing, you should be fine.. if you don't.. don't guess... might not turn out so good..

[Godney]

Back to what Ken said we are talking about the output side of the controller and as Tim said (if you don't know what you are doing this kind of set up can get you in a lot of TROUBLE.) Since i have been working with electronics and electricity since i was 13 i have a clear understanding of this circuit design

[plasmadrive]

Back to what Ken said we are talking about the output side of the controller and as Tim said (if you don't know what you are doing this kind of set up can get you in a lot of TROUBLE.) Since i have been working with electronics and electricity since i was 13 i have a clear understanding of this circuit design

Then you should be fine..  I don't see any issue with it on the output side at all..

[Steven]

Finally, you need to be 100% sure that your outlets and controllers are wired properly, with the neutrals on the wide prong and the hots are on the smaller plug.  If not, you can easily have a situation where you have a suicide plug (a male plug with a hot prong).

 

I will go further than this and say that if you use a shared neutral, you should not use 2-prong plugs and sockets at all. The reason is that even if they are wired properly, you can create a situation that will most often happen during the process of plugging/unplugging. If you happen to be holding onto the neutral connector of one plug, and you plug another plug into a channel that happens to be on (and I always have my channels on when I am setting up my display so I can be aware when something is not working), and you manage to insert the hot side first (one has to be first), then the current can flow through those lights back on the common neutral and onto the plug you are holding in your other hand!

 

What I do when I have shared neutrals is to replace the 2-prong sockets with multi-pin Molex connectors like this: