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I'm in a long slow process of building a control panel for our layout.  I first thought I would want a voltmeter and an ammeter for each ZW output, but then I realized I probably wouldn't have much of a load on any single output.  I have 10 amp magnetic circuit breakers on each output. 

 

The ZW outputs handle the following:

A: Lower level track

B: 022 switches (12)

C: Accessories

D: Upper level track

Is it worth it to see the ammeter reading bouncing around 2-3 amps on each output? Or should I only use one ammeter for the entire layout (commonly wired as ZW is only power source) to monitor total power draw of the ZW? What is really important here?

Granted the meters are more for fun and visual effect than truly monitoring the voltage and amp draw, but I think it would be interesting to see how much the switches are drawing, and comparing that to a heavy train pulling up the grade.  I'm leaning towards 1 ammeter for each output, but if it is better to monitor / consider total draw of the transformer, then I'll think about adjusting my approach.

Control Panel:

Control Panel

Meter cluster:

Meters

If wiring ammeters into each individual output:

Volt_Amp%20Meters

If wiring 1 ammeter for total ZW amp draw:

Volt_Amp%2520MetersJGL2

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  • Control Panel
  • Meters
  • Volt_Amp%20Meters
  • Volt_Amp%2520MetersJGL2
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Use an amp meter for each track. The amps should not be jumping around. Once you see the normal amperage draw     thats your guide. If you see a spike say 2 amps jumping to 4 amps then that is a warning that attention to an engine may be needed. Also adding lighted cars may be taking you to the power limit of your power supply which you will clearly see. Each engine will most likely have it’s own base point. I think meters are fun and add visuals to ensue things are good. 

Thanks, Charlie and Rod. 

I operate mostly postwar motors and haven’t converted anything to LEDs, so the amps pulled on each circuit may be worth monitoring like Rod suggests. It would be easier to isolate an issue if they are separated.

So let’s say I do have 4 ammeters, 1 for each throttle, can I simply add each value for the total on the transformer? 

If I have a cumulative 14 amps across the all 4 meters (ie, 4+3+3+4), I could expect to be near the limit of the 15amp internal breaker of the zw? 

 

Last edited by JD2035RR
Jon1443 posted:

Where's the best place to buy panel-mount volt and ammeters?

Below are the links to where I purchased mine, shipping was free.  They took about 2-6 weeks to finally arrive.  They seem to be of nice quality, although I can not speak to their accuracy as I have not wired them up yet.  Is this the best? I don't know, but it seemed to suffice for now.

$3.28 0-20V  Voltmeter:

https://www.ebay.com/itm/85L1-...p2060353.m1438.l9372

$4.89 0-15 Amp Ammeter:

https://www.ebay.com/itm/AC-15...p2060353.m1438.l9372

 

MichRR714 posted:
...I rarely pull more than 5 amps running 2 PW ZW's and a Z on my layout....

I think you already know this, but I'd like to make a point of clarification on amp draw for those reading this thread.

A piece of electronic equipment will only draw the amount of current (the amps) it needs to run, no matter how much current the power supply is capable of delivering. If you have a train that draws 4 amps at 18 volts when it is being powered by a 275 watt ZW, it will still only draw 4 amps at 18 volts, even if it was powered by a 25,000 watt transformer.

Another analogy...
If you have a 12-volt grain of wheat light bulb and you connect it to a tiny little 12-volt, 1-amp power supply, what happens? It lights up just fine. What happens if you connect that same bulb to a 12-volt car battery capable of delivering over 1,000 amps? Nothing. It lights up just as it did when using the little 1-amp supply. The light only draws the power (amps) it needs to operate.

The same principle holds true for ALL electronic gear, whether it is a model train, your computer, an electric razor, the lights in your home, or even a massive electric traction motor on a diesel locomotive.

JD2035RR posted:
Jon1443 posted:

Where's the best place to buy panel-mount volt and ammeters?

Below are the links to where I purchased mine, shipping was free.  They took about 2-6 weeks to finally arrive.  They seem to be of nice quality, although I can not speak to their accuracy as I have not wired them up yet.  Is this the best? I don't know, but it seemed to suffice for now.

$3.28 0-20V  Voltmeter:

https://www.ebay.com/itm/85L1-...p2060353.m1438.l9372

$4.89 0-15 Amp Ammeter:

https://www.ebay.com/itm/AC-15...p2060353.m1438.l9372

 

Thanks JD. Time to put that ebay gift card to good use. 

Rich's statement relates to: yes, you can do the math for a total from 4 meters if you wanted to skip a 5th. You could also use one, two, or three directly monitored lines and/or common meters, just to have one or two lines with the ability directly monitor equipment with; "the test bench line". E.g. trk#1&2 on A&D and acc & lights on B&C, #1&2 might share a meter, or be individuals, or #2 might not get one, opting to monitor the accessories on B instead... light bulbs you can add up. Get to know your engines and it will tell you when you're overdue for cleaning or even lube. (increased voltage setting needs are another sign) With 10a breakers, every wire thereafter must handle 10a easily. Then you add a fuse to step down to BELOW each smaller wire's max capibility on power delivery . (power delivery that never rests needs to be on the fat side of awg limits; more heat doing that than a signal or temporary on) Your drops can be under the max a bit because they all deliver to the same draw and so can be added and averaged more broadly. Fuse,breaker, and wire gauge design is based on saftey and limiting damage when things go wrong. The meters are great but that's where you shouldn't "settle". Wire for 18a, supply 15a,10a thermal breakers, a set of magnetic #91s, sleep while it runs.
JD2035RR posted:

Thanks, Charlie and Rod. 

I operate mostly postwar motors and haven’t converted anything to LEDs, so the amps pulled on each circuit may be worth monitoring like Rod suggests. It would be easier to isolate an issue if they are separated.

So let’s say I do have 4 ammeters, 1 for each throttle, can I simply add each value for the total on the transformer? 

If I have a cumulative 14 amps across the all 4 meters (ie, 4+3+3+4), I could expect to be near the limit of the 15amp internal breaker of the zw? 

 

Have you already calculated your expected total amperage draw?  Although the breaker won’t trip until you reach 15 amps, according to the attached page 23 from the 1965 Lionel Operating Manual, the continuous amperage rating of a postwar ZW is only 12 amps.  The lamps in all 12 of your O22 switches and their controllers will draw 4.8 amps, which is 40% of the ZW’s capacity.  If you are running one single-motor, single-headlight postwar engine on each of your 2 mainlines you’ve added 2.9 amps.  So based on what you’ve described so far you’re at 7.7 amps or 64% of your transformer’s continuous capacity.    

You haven’t said how many lighted accessories you have or if you are running any passenger cars or double-motor engines but if you are you could be close to that 12 amp threshold.  A second motor in a postwar diesel would add 1.25 amps and each passenger car with 2 lamps will add 0.4 amps.  Each continuously lighted lamp, whether in an accessory, a caboose, a searchlight car or a second headlight on a diesel will add 0.2 amps.  So you may be close to overloading that ZW already.  You might want to consider buying LED’s to replace many of your postwar-era lamps.  They’ll last longer, too.

HTH,

Bill

1965_Page_23

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Images (1)
  • 1965_Page_23: Page 23 from 1965 Lionel Operating & Instruction Manual

Having a pair of meters for each channel is the way to go. Good for monitoring protentional issues on the fixed channels. switch coils or bulbs going bad, track rails beginning to short on the switch channel for example. 

yes, you can add the amperage total easily or just wait for a breaker to kick. What is the break percentage on the magnetic breaker? That will kick first before the transformer's thermal breaker. Do you have one for each output?

You can monitor amperage with a simple Snap/loop AC amp meter.  These meters measure the magnetic field associated with the AC current flow of a wire.   Difficult part of a traditional Amp meter system is that the meter has to be part of the circuit  Old Analog Clamp amp meter. 

An interesting adapter 

?? 40 years ??   

Last edited by Mike CT
WftTrains posted:
JD2035RR posted:

Thanks, Charlie and Rod. 

I operate mostly postwar motors and haven’t converted anything to LEDs, so the amps pulled on each circuit may be worth monitoring like Rod suggests. It would be easier to isolate an issue if they are separated.

So let’s say I do have 4 ammeters, 1 for each throttle, can I simply add each value for the total on the transformer? 

If I have a cumulative 14 amps across the all 4 meters (ie, 4+3+3+4), I could expect to be near the limit of the 15amp internal breaker of the zw? 

 

Have you already calculated your expected total amperage draw?  Although the breaker won’t trip until you reach 15 amps, according to the attached page 23 from the 1965 Lionel Operating Manual, the continuous amperage rating of a postwar ZW is only 12 amps.  The lamps in all 12 of your O22 switches and their controllers will draw 4.8 amps, which is 40% of the ZW’s capacity.  If you are running one single-motor, single-headlight postwar engine on each of your 2 mainlines you’ve added 2.9 amps.  So based on what you’ve described so far you’re at 7.7 amps or 64% of your transformer’s continuous capacity.    

You haven’t said how many lighted accessories you have or if you are running any passenger cars or double-motor engines but if you are you could be close to that 12 amp threshold.  A second motor in a postwar diesel would add 1.25 amps and each passenger car with 2 lamps will add 0.4 amps.  Each continuously lighted lamp, whether in an accessory, a caboose, a searchlight car or a second headlight on a diesel will add 0.2 amps.  So you may be close to overloading that ZW already.  You might want to consider buying LED’s to replace many of your postwar-era lamps.  They’ll last longer, too.

HTH,

Bill

1965_Page_23

Good advice, Bill.  I think I will be getting LED replacements for the switches - what a power hog!

I didn't realize the 12 amp continuous number.  I am currently having my ZW serviced with a new breaker installed.  I'll have to ask them what they are replacing it with.

I wouldn't want to rule out a double motored engine on both mains either.  I have a few lighted accessories 450 signal bridge, gateman, whistle station, log loader, etc. --- it all adds up!

My estimate using the sheet you provided put me at 12.4 - assuming I was running dual motored locos on each main, and operating one of the postwar AC motored accessories, and had traditional light bulbs everywhere.  I think the LEDs bulbs is a great suggestion and would allow for additional track side signals, etc.

 

Moonman posted:

Having a pair of meters for each channel is the way to go. Good for monitoring protentional issues on the fixed channels. switch coils or bulbs going bad, track rails beginning to short on the switch channel for example. 

yes, you can add the amperage total easily or just wait for a breaker to kick. What is the break percentage on the magnetic breaker? That will kick first before the transformer's thermal breaker. Do you have one for each output?

Thanks for your input.  Each throttle A,B,C, and D will have the Sensata AirPax 10.0 amp magnetic breaker (https://www.onlinecomponents.c...tm_campaign=eciaauth) on the "hot" side. 

I'm not entirely sure how to read its spec sheet, but I think this says it will trip at 135% (13.5amps) at 0.10 seconds. If 150%, then it should pop at 0.001 seconds.  If someone could clear up how to read the chart that would be helpful

2019-04-25 09_00_42-PP11-0-10.0A-OB-V-AIRPAX _ SENSATA-Datasheet2019-04-25 09_02_17-PP11-0-10.0A-OB-V - Airpax _ Sensata Authorized Distributor

 

Attachments

Images (2)
  • 2019-04-25 09_00_42-PP11-0-10.0A-OB-V-AIRPAX _ SENSATA-Datasheet
  • 2019-04-25 09_02_17-PP11-0-10.0A-OB-V - Airpax _ Sensata Authorized Distributor
Last edited by JD2035RR

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