Handy Wire Voltage Drop Calculator

That looks really detailed, a wealth of info there. Looks like a very useful tool for folks here having wiring questions or trying to figure out their wiring needs for their layouts. I saved it and will experiment with it later. Thanks for going to all the trouble to create this and post it to share with us.

Very nice spread sheet

Ken M

Looks good Rod.  I'd consider changing the color of all the stuff at the top since you said the users should only modify the yellow entries.

Another point, to make it compatible with a maximum number of people, consider saving it in Excel 2003 format.  I'm sure there's nothing in there that would be affected, and I know people still using the old version.

I think there should be a place to post stuff like this where it's readily accessible.

Good feedback John; thanks.

The protected version allows only the changing of the 5 main yellow highlighted input cells, so hopefully nothing in the upper data table will get messed up.

If I get any requests for earlier Excel versions I will certainly save it back to that and repost it.

Thanks Ken and rtr12 for your kind words.

Rod

Good job. You really 1up'ed the post I did here:

https://ogrforum.ogaugerr.com/t...11#36766446979280111

I use Microsoft's compatibility pack to view the 2007+ .xlsx files on Excel 2003. Its free.

http://www.microsoft.com/en-us...ad/details.aspx?id=3

Definitely, this would be a great idea! Something like the 'Sticky's' for the DCS and Legacy reference materials that I believe you talked them into. Maybe you could drop Rich a suggestion.  

I have suggested this about some other posts, but so far no luck. There are some threads floating around here that should really be saved somewhere and located so they can be readily found when needed. There is truly a lot of good information around here if one can just find it again.

Matt,

i had not been on the forum until lately, and did not see the topic you linked to. My apologies. Lots of good info in that topic, including your post IMO. 

I just automated the wire selection process a little! 

Rod

I note that the amp ratings you give--15 for 14 gauge and 20 for 12 gauge--are the National Electric Code ratings for NM cable, what is usually used for house wiring, and is directed towards wire overheating.  When my wife plugs in her iron, 10 amps, on a 15-amp circuit, lights on that circuit noticeably dim.  But the voltage drop doesn't mean much on that circuit.  But, if I put a 10 amp load on an 18-volt line and get a similar voltage drop, the effect will be substantial.

Thus, if I am going to pull 10 amps for a power district, using either 14 or 16 gauge wire I needn't worry about overheating the wire, but I would use 14 because the effect of voltage drop at the lower train voltages has substantial effect

RJR;

Good comment.

It all comes down to what is a tolerable voltage drop.

I suggest no more than 2 volts loss for track feeds @ 18 VAC for command use, because you are not likely to notice this drop in normal train ops.

But that loss would be too much for a 6 or 12 volt service, as you note.

For these I generally try to limit the loss to 1 volt or less.

Rod

The voltage drop computation that is also in the sheet addresses the voltage drop nicely, you can see what the situation is for various wire sizes and run lengths.  You get to decide how much voltage drop is tolerable for your situation.

No apologies needed. I liked your spreadsheet

Thanks!  Very useful!

Just bumping this forward so it doesn't get too far lost in the back pages.

Rod

Rod, this might be a candidate for the ELECTRICAL REFERENCE MATERIALS & MANUALS thread.  It is a very useful tool.

One suggestion.  Can you expand the upper limit to include up to #30 wire?  For LED's, I like to be able to reference something when the question comes up about fine wiring.

Good idea John; let me take a look.

Rod