Wiring question

If you are measuring at the transformer and at the track with the same true RMS voltmeter, then yes, go up a couple gauges in wire size and measure again.

Are you measuring the voltage with our without power being drawn? Disconnect the wires from your lockon and measure the voltage at the disconnected wires. It should be the same as at the transformer. If is not the same as at the transformer, you need to check the connections at the transformer.

I would say you need a larger gauge wire so you font have so much voltage drop due to the resistance of the wire, the larger the wire the better I would use at least 14 or 12 gauge wire and your problem will go away ok , good luck, 12 gauge would definitely be good but would cost a little more ok

Alan

I was guessing that he's reading the voltage on the transformer and measuring the voltage with a different meter and the two don't agree.

I agree, Chuck. 4' is not usually going to give you a 4 volt drop, especially without a load.

cjack posted:

I was guessing that he's reading the voltage on the transformer and measuring the voltage with a different meter and the two don't agree.

I did use the same meter at both the transformer and the end of the wire where it connects to the lockon.  I disconnected the wire from the lockon so there would be not load.  That is the readings I received.  I will try a heavier gauge wire and see what results I get.

Must be a bad connection. Even 26awg at .1 amp only loses 10% in 200', according to the spreadsheet I use.

I agree with John,

If you see a drop with the lockon disconnected, there's most likely a mechanical problem. Check to make sure the connections are tight and you are not clamping down on the insulation and not the wire.

-Lad

Using the assumption that your gauge is 16 ga. wire at ONLY 4 feet, the resistance is .016 ohms.  If you get a 4 volt drop with that resistance, the mechanical connection is at fault.  There is NO way a .016 resistance will give you a 4 volt drop.  If the wire size is 12 ga. The resistance is .006 ohms, so there is no inherent advantage at a meager length of 4 feet, by increasing the wire size.  Make the length 400' and that is a whole new ballgame.

Thanks for all the suggestions.  I will post when I determine what worked. 

I have resolved the cause of the voltage drop.  It is load based.  When there is no load, just wiring to the track, the voltage is constant from the transformer, to the track with no drop.  When I add a locomotive, voltage drops about 1 volt.  When I add six old style passenger cars (I believe they have light bulbs), the voltage drops another 3+ volts.  At least I know what causes the voltage drop.

Thanks to everyone for their suggestions.

That's great news. If you have a 4 volt drop to the lockon, then you should probably consider increasing the size of the wire between the transformer and lockon. I would still also check for loose connections or possibly a loose terminal post since I doubt even 18 gauge should have that much voltage drop over 4 feet.

-Lad

You should use larger diameter wire and maybe better connections. That's a bit too much drop.

JDA posted:

I have resolved the cause of the voltage drop.  It is load based.  When there is no load, just wiring to the track, the voltage is constant from the transformer, to the track with no drop.  When I add a locomotive, voltage drops about 1 volt.  When I add six old style passenger cars (I believe they have light bulbs), the voltage drops another 3+ volts.  At least I know what causes the voltage drop.

Thanks to everyone for their suggestions.

You might want to measure the voltage right at the transformer terminals when you add the locomotive and passenger cars. I would bet that most of the voltage drop is in the transformer, not the wiring.

If you work through the math, #16 copper wire loses 1 volt for every 250 ampere-feet of circuit; with #18 it is 1 volt per 150 ampere-feet. If you are losing 4 volts through 8 feet (round trip length) of number 16, it means the wire is carrying 125 amperes! If your wires are #18, you are drawing 75 amperes, both of which are impossible with a Z4000.

How the power gets to the rails on my layout. From the starting point. This may give you some ideas for what you are doing with your layout. Below is a wire diagram.

1.  Starts at the homes power panel in the train room. Leaves on a dedicated 15 amp circuit. This line is also GFI. The panel also has a whole house surge protector.

2.  Enters the layouts control panel and enters a Kill Lighted Switch.

3.  Than the power goes to a junction box with 4 plugs, the outlet than breaks out into 4 power Surge / Arrest Protectors. Everything on the layout is plug into these strips with space left over.

4.  The power now enters 4 Lionel 180 Watt Powerhouse Bricks, on the end of each Lionel Brick is a male plug.  These 4 male plugs are plug into the back of a Lionel ZW Transformer.

5.  The power leaves the ZW on 14 Gauge Stranded Wire. Next it goes to the MTH / TIU.  There are 4 throttles - Left to right on the ZW-C - Track 4 / Track 3 / Track 2 / Track 1.

6.  The wire is attached to the Track Interface Unit on the Input Side with, Klein / Ideal Terminal Connectors. Track 4 to =  Fixed Voltage,  Track 3 to = Variable Voltage,   Track 2 to =  Variable Voltage, Track 1 to =  Fixed Voltage. This means that the large throttles on the ZW are fixed and the small inter throttles on the ZW-C are variable voltage.

7.  The power leaves the Track Interface Unit on the Out Put side and goes to several MTH 50-10-1020 24-Port Terminal Blocks, This block sends the current to the layout control panel that sends the power to the tracks and sidings, using single pole, single throw switches.

8 - Each main line has 3 blocks so I can run conventional locos, using the throttles on on the Lionel ZW. Old school operations. The 14 gauge wire is solder to the track about every 6 feet to the inside of the rails.

9 - The Lionel TMCC is wired to the TIU with a MTH cable 50-1032 and a 14 gauge ground wire. Each main line is about 100 feet of tubular track.