ANALOG PANEL AMP METERS

Hello I would like to install 4 panel Amp meters on my layout. One for each of my 4 power districts. I bought 4 of these but they didn't come with a schematic. Can anyone tell me how to wire these or provide a wiring diagram? Thanks. Nick

                                                                                                                             

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That is a current transformer. Usually these are on big current, not something this small. Surprising to see this combination for the small current we run. I bought 0-20 amp analog meters on ebay for less than $10 each and no current transformer required, just run the line through the meter. Based on the meter, my guess is you don't need the current transformer. Test it slowly on one district.

Hokie 71

Chief of Operations, Free Union, Blacksburg, and Albemarle Railroad (FUBAR)

Rockstars 1989, It sounds like you already have purchased the ones in the pics but I have found that those won't read when polarity reverses (when you reverse the train).  I use these on my DC G Scale layout, they are zero center and read correctly on reversed polarity.

DC-Analog-Volt-Meter-Panel-Mount-15-0-15-PM15015-DC
 
 DC Analog Volt Meter Panel Mount 15-0-15 PM15015-DC
 
 
 
DC-Analog-Ammeter-20-0-20-Amps-DC-MS52-type
 
  • DC-Analog-Ammeter-20-0-20-Amps-DC-MS52-type
  • DC-Analog-Ammeter-20-0-20-Amps-DC-MS52-type
    DC-Analog-Ammeter-20-0-20-Amps-DC-MS52-type
 
DC Analog Ammeter 20-0-20 Amps DC MS52 type
 
 

Chris S.

hokie71 posted:

That is a current transformer. Usually these are on big current, not something this small. Surprising to see this combination for the small current we run. I bought 0-20 amp analog meters on ebay for less than $10 each and no current transformer required, just run the line through the meter. Based on the meter, my guess is you don't need the current transformer. Test it slowly on one district.

Thanks Hokie I will bench test first. I got these free from an electrician in one of the plants I visit. Nick

                                                                                                                             

Heres a picture from an old layout showing the wiring on the rear of a 3 power district meter panel. Colored wires are the Hot wire runs from 3 separate PoHo transformers to the ammeters on the bottom row. Note the Hot wires connect the ammeters inline(in series thru the meters) and return to the load (the center track rails) The white wire connected to the 3 volt meters is the Common (combined common from the 3 phased PoHos and is also extended to the outer rails). It connects across the line (in parallel) and jumpers power to the volt meters on the top row. To complete the across the line, Hot to Common, connection of the Volt meters one can see the short HOT jumpers extended  up from the ammeter terminals. The hot wires must be a heavy gauge wire since the full load runs thru the ammeters. If you are using Command Control the volt meters will show a steady 18 volts. The ammeters will reflect the railpower load  of the locomotives plus car lighting. 

In this case the Volt Meters used were 0-25 VAC and the Ammeters are 0-15 AAC. Hope this helps.

 

 IMG_1990

 

Image

A&Y RY[NC's Southern/N&W connector].

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rockstars1989 posted:
hokie71 posted:

That is a current transformer. Usually these are on big current, not something this small. Surprising to see this combination for the small current we run. I bought 0-20 amp analog meters on ebay for less than $10 each and no current transformer required, just run the line through the meter. Based on the meter, my guess is you don't need the current transformer. Test it slowly on one district.

Thanks Hokie I will bench test first. I got these free from an electrician in one of the plants I visit. Nick

Hokie I ran the amp meters in series with the load I also used my inductive amp probe on the same line to verify the analog meter is reading 5 or 6 amps higher than my amp probe. So Im not sure what to do now.I will try and investigate DEWEYS suggestion. Any other Ideas? Can you send me a link to the meters you bought? Thanks for your help. Nick

                                                                                                                             

Dewey Trogdon posted:

Heres a picture from an old layout showing the wiring on the rear of a 3 power district meter panel. Colored wires are the Hot wire runs from 3 separate PoHo transformers to the ammeters on the bottom row. Note the Hot wires connect the ammeters inline(in series thru the meters) and return to the load (the center track rails) The white wire connected to the 3 volt meters is the Common (combined common from the 3 phased PoHos and is also extended to the outer rails). It connects across the line (in parallel) to the volt meters on the top row. To complete the across the line, Hot to Common, connection of the Volt meters one can see the short HOT jumpers extended  up from the ammeter terminals. The hot wires must be a heavy gauge wire since the full load runs thru the ammeters. If you are using Command Control the volt meters will show a steady 18 volts. The ammeters will reflect the railpower load  of the locomotives plus car lighting. 

In this case the Volt Meters used were 0-25 VAC and the Ammeters are 0-15 AAC. Hope this helps.

 

 

 

 

 Image

OK Dewey so the 3 power feeds run in series through the amp meters. Then off each of the amp meters you are feeding a volt meter and have a common daisy chained white across the common side of the volt meters. I think I understand that. My problem is my amp meters are reading much higher than they should I verified this with my inductive amp probe. Is it possible the amp meters I have are wrong? Can you provide a source for the proper amp meters? Thanks for your help. Nick

                                                                                                                             

The Shurite meters I used on this panel were good quality from Allied Electronics{ google them and Newark Electronics] Also you can get meters from Light Object, Inc for about $10 that are just fine for Toy Train operations. These are simple meters  with about 1-1/2 to 2-1/2  % variation. No shunt involved --I am unsure regarding your "sensor" meters.

A&Y RY[NC's Southern/N&W connector].

A 5a difference makes me think they need the sensor.

  Have you tried the sensor?  The power line would simply pass through the hole.

  How about a shot of all terminals and thier markings and or Is there an mfg. name on the meter? (look on the dial first)

Are you still running in command? Ive read there can be issues with meters & command.

"Still trying to not shoot my eye out"

 

"Nursing insomnia one railcar at a time"

My aroma therapy? Smoke Pellets.

 





Follow up the best source I found with the best quality for a reasonable amount of money was Amazon.You can get Simpson meters but they are $ 100.00 per. I will report back on my progress.Thanks everybody. Nick

                                                                                                                             

Rockstars and Dewey are late night workers! Based on that error, the meter must be set up to work with the current transformer as Adriatic mentions.  My guess is that the wire that ran through the CT was maybe going to a large motor at 460 volts or higher for example and obviously we don't want that in a control panel with meters so they used the current transformer.  for the cheap price of these panel meters on ebay, my guess is you may not want to use this set up considering the extra space and wiring it will need.

Here is a picture of my districts and I also used two of these for my dedicated accessory circuits.  You can also see I added a fuse to begin each one. Here is the meter I bought on ebay for under $5. Whoops, that was 15 amps, here is the 10 amp full scale one.  

 

PS- the one you found  should work too.  

100_5858100_5860

Hokie 71

Chief of Operations, Free Union, Blacksburg, and Albemarle Railroad (FUBAR)

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hokie71 posted:

Rockstars and Dewey are late night workers! Based on that error, the meter must be set up to work with the current transformer as Adriatic mentions.  My guess is that the wire that ran through the CT was maybe going to a large motor at 460 volts or higher for example and obviously we don't want that in a control panel with meters so they used the current transformer.  for the cheap price of these panel meters on ebay, my guess is you may not want to use this set up considering the extra space and wiring it will need.

Here is a picture of my districts and I also used two of these for my dedicated accessory circuits.  You can also see I added a fuse to begin each one. Here is the meter I bought on ebay for under $5. Whoops, that was 15 amps, here is the 10 amp full scale one.  

 

PS- the one you found  should work too.  

100_5858100_5860

Very nice set up Yea Rockstars don't sleep! Nick

                                                                                                                             

Nick  I am pretty sure your problem is that you need to use the second component with the hole in the center like Adriatic mentioned.    The 2nd component, with the hole in the center,  is most likely an amprobe designed to be dedicated to the amp meter.... like your using on your hand  held meter.   The AC hot to the center rail of your power district just needs to run through the hole, and not be connected directly to the back of the AC Amp Meter....  There should be a lead from the sensor probe that you connect to the meter itself.   It's probably designed for higher voltage circuits that you wouldn't want running to the back of a panel....   20 Amps at 240vac, or 460 vac is alot more energy (power) than 20 amps at 18 vac.   

The amprobe should then be connected to the amp meter.  If you're getting a current signal that's higher than your amprobe, it's because you are running the AC hot track power directly through the meter.    I don't think you need to buy anything else, just try hooking up what you have without running the AC track power through the meter directly. 

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