rrinker OK, that's more like it. I was worried you had a 1.65 amp reading with nothing on the track. That would indicate some serious wiring problems. If that the current draw with the terminal full of locos, even with the sound off, it's not an unreasonable number for that count of locos. That also explains the 1156 bulb tripping things out, if you are starting at 1.65 amps, adding another 2.1 takes you well over a reasonable 3 amp setting for any given power district.
OK, that's more like it. I was worried you had a 1.65 amp reading with nothing on the track. That would indicate some serious wiring problems. If that the current draw with the terminal full of locos, even with the sound off, it's not an unreasonable number for that count of locos.
That also explains the 1156 bulb tripping things out, if you are starting at 1.65 amps, adding another 2.1 takes you well over a reasonable 3 amp setting for any given power district.
Rich
Alton Junction
OK, that's more like it. I was worried you had a 1.65 amp reading with nothing on the track. That would indicate some serious wiring problems. If that the current draw with the terminal full of locos, even with the sound off, it's not an unreasonable number for that count of locos. That also explains the 1156 bulb tripping things out, if you are starting at 1.65 amps, adding another 2.1 takes you well over a reasonable 3 amp setting for any given power district.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
rrinker Wait, you get one booster delivering 1.65 amps with nothing connected to the track? With no locos, lighted cars, resistor wheel cars, accessory decoders connected to the track bus, and no errant tools on the track, you should get basically 0 amps. Maybe a small number if you twised the bus, but even the .25 seems high, and 1.65 is DEFINITELY wrong. Or is the engine terminal full of locos?
Wait, you get one booster delivering 1.65 amps with nothing connected to the track? With no locos, lighted cars, resistor wheel cars, accessory decoders connected to the track bus, and no errant tools on the track, you should get basically 0 amps. Maybe a small number if you twised the bus, but even the .25 seems high, and 1.65 is DEFINITELY wrong.
Or is the engine terminal full of locos?
At first, I was taking a pair of diesels off the tracks at a time to see if the 1156 bulb shorting would stop. When I reached 10 diesels off the tracks, the shorting stopped and the current draw had dropped 0.50 amps, an average of 0.05 per loco which matched the reading on the in-line RRampMeter.
I get less than .25 amps running my soundequipped Atlas RS3 on my test track. That's sound playing, lights on, and motor turning.
richhotrain rrinker 1/2 volt drop is no big deal, somethign to shoot for, The second aprt of the test is to get a quarter. Set it on the rails, all along each section, from nearest to farthest. Does the breaker trip every time? Particualrly at those spots where you read 10.9 volts under load. If setting a quarter across the rails trips the breaker, then you should be good. If it doesn't, that means there is too much resistence in the bus, and you can potentially pass right up to the breaker setting through the wheels or wiring of the loco continuously with the breaker not shutting it off. The breaker needs to be able to cut the power immediately upon sensing a short, if there is too much drop, caused by too much resistence, then what ought to be a dead short might not be. As little as 5 ohms at 12 volts is less than 3 amps, so if the breaker is set at 3 amps, it wouldn't trip if there is 5 ohms in the wiring, even if you used clip leads to connect the rails to generate a short. I like that idea. Thanks, Randy. I will do some quarter tests in the morning and post the results. Rich
rrinker 1/2 volt drop is no big deal, somethign to shoot for, The second aprt of the test is to get a quarter. Set it on the rails, all along each section, from nearest to farthest. Does the breaker trip every time? Particualrly at those spots where you read 10.9 volts under load. If setting a quarter across the rails trips the breaker, then you should be good. If it doesn't, that means there is too much resistence in the bus, and you can potentially pass right up to the breaker setting through the wheels or wiring of the loco continuously with the breaker not shutting it off. The breaker needs to be able to cut the power immediately upon sensing a short, if there is too much drop, caused by too much resistence, then what ought to be a dead short might not be. As little as 5 ohms at 12 volts is less than 3 amps, so if the breaker is set at 3 amps, it wouldn't trip if there is 5 ohms in the wiring, even if you used clip leads to connect the rails to generate a short.
1/2 volt drop is no big deal, somethign to shoot for,
The second aprt of the test is to get a quarter. Set it on the rails, all along each section, from nearest to farthest. Does the breaker trip every time? Particualrly at those spots where you read 10.9 volts under load. If setting a quarter across the rails trips the breaker, then you should be good. If it doesn't, that means there is too much resistence in the bus, and you can potentially pass right up to the breaker setting through the wheels or wiring of the loco continuously with the breaker not shutting it off. The breaker needs to be able to cut the power immediately upon sensing a short, if there is too much drop, caused by too much resistence, then what ought to be a dead short might not be. As little as 5 ohms at 12 volts is less than 3 amps, so if the breaker is set at 3 amps, it wouldn't trip if there is 5 ohms in the wiring, even if you used clip leads to connect the rails to generate a short.
I like that idea. Thanks, Randy. I will do some quarter tests in the morning and post the results.
richhotrain RR_Mel Being as you have built in DCC current meters you can monitor the current of each consist under load at your running speed, I doubt the current even approaches 1 amp. A pair of my locomotives with dual motors rarely draw more than 900ma on my 3% grades at running speed (scale 50MPH ± 2 or 3MPH guesstimate). Thanks, Mel. I will post the amp readings for each in-line RRampMeter. Rich
RR_Mel Being as you have built in DCC current meters you can monitor the current of each consist under load at your running speed, I doubt the current even approaches 1 amp. A pair of my locomotives with dual motors rarely draw more than 900ma on my 3% grades at running speed (scale 50MPH ± 2 or 3MPH guesstimate).
Being as you have built in DCC current meters you can monitor the current of each consist under load at your running speed, I doubt the current even approaches 1 amp. A pair of my locomotives with dual motors rarely draw more than 900ma on my 3% grades at running speed (scale 50MPH ± 2 or 3MPH guesstimate).
Thanks, Mel. I will post the amp readings for each in-line RRampMeter.
The other RRampMeter shows 1.65 amps without load. This booster district controls the large passenger station and the engine servicing facility where most of the locos will reside at any one time.
I have a voltmeter and a Rob Paisley DCC ammeter in line with my track mounted in my control panel and watch the current closely. I run dual mode, DC or DCC, more DC than DCC.My max voltage loss is .1 volts pulling my grades with a full load, two heavy E7s (2 pounds each) towing 13 heavy passenger cars at a scale 50 MPH draw 890ma total at 14.3 DCC volts using #20 AWG solid wire longest run 15’.Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
gregc when multiple locomotives draw ~1A combined, most of that current is carried on the bus between the booster and loco closest to the booster, not the track
when multiple locomotives draw ~1A combined, most of that current is carried on the bus between the booster and loco closest to the booster, not the track
Being as you have built in DCC current meters you can monitor the current of each consist under load at your running speed, I doubt the current even approaches 1 amp. A pair of my locomotives with dual motors rarely draw more than 900ma on my 3% grades at running speed (scale 50MPH ± 2 or 3MPH guesstimate). Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
greg - Philadelphia & Reading / Reading
RR_Mel If it was my layout I doubt if I would ever load a section or block of track more then 1 amp (two Locomotives) which drops the loss by half and I wouldn’t worry about a drop of .4 volts, especially at 80’. EDIT: 80 foot one way (160' both wires) #14 AWG wire has .25 volts drop at 2 amps, solid wire no conections. Add in a bit here and there for connections and you've got your measured loss.
If it was my layout I doubt if I would ever load a section or block of track more then 1 amp (two Locomotives) which drops the loss by half and I wouldn’t worry about a drop of .4 volts, especially at 80’.
EDIT:
80 foot one way (160' both wires) #14 AWG wire has .25 volts drop at 2 amps, solid wire no conections. Add in a bit here and there for connections and you've got your measured loss.
80 foot one way (160' both wires) #14 AWG wire has .25 volts drop at 2 amps, solid wire no conections. Add in a bit here and there for connections and you've got your measured loss. Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
I got my portable RRampMeter yesterday, and I connected an 1156 automotive bulb to it to test voltage drop under load. Here is a summary of the results.
Without load, voltage measures 13.7 up and down the mainlines and on the four reversing sections.
Under load, the 80' long U-shaped bus configuration connects to the booster at both ends of the bus. The closest voltage reading is 11.7 and at the far end of the bus, voltage measures 11.2. So, a 0.5 voltage drop over 40'.
Under load, the other 80' bus configuration connects to the same booster. The closest voltage reading is 11.7 and at the far end of the bus,voltage measures 10.9. Due to the bus configuration, that far end is only 60' from the booster. So, a 0.8 voltage drop over 60'.
Under load, the two reversing sections close to the booster (within about 20'), the voltage ranges from 11.4 to 11.1, The two reversing sections farther from the booster (50' to 60'), the voltage ranges from 11.2 to 10.9. So, voltage drops of 0.6 and 0.8.
Do those voltage drops seem moderate?
rrinker It all depends on your operating scheme. It COULD result is less voltage drop if each direction main had its own buss, but if only oen train is ever running, it won't matter if there is one bus running between paralle tracks with feeders to both tracks, or two busses with feeders only to their respective tracks.
It all depends on your operating scheme. It COULD result is less voltage drop if each direction main had its own buss, but if only oen train is ever running, it won't matter if there is one bus running between paralle tracks with feeders to both tracks, or two busses with feeders only to their respective tracks.
If there will be a train running both ways at the same time - you have cut the current draw per bus in half and thus the voltage drop, by having half the load in one bus and half in the other.
rrinker Yes. Either 2 breakers on each booster, one feeding the middle of the 80' bus for main #1, and one feeding the middle of the 80' bus run for main #2 (so two busses - one for each main) OR 4 breakers at each booster, each breaker powering 40' of bus for each main. 40' of main protected per breaker may be a bit overkill, depending on how you plan to operate. It may be more effective to use one breaker for each main at each booster (4 breakers) and then have a yard on its own breaker. --Randy
Yes.
Either 2 breakers on each booster, one feeding the middle of the 80' bus for main #1, and one feeding the middle of the 80' bus run for main #2 (so two busses - one for each main) OR 4 breakers at each booster, each breaker powering 40' of bus for each main.
40' of main protected per breaker may be a bit overkill, depending on how you plan to operate. It may be more effective to use one breaker for each main at each booster (4 breakers) and then have a yard on its own breaker.
Ever since I first divided my DCC layout into separate power districts some years back, I have always put both mainlines into one power district (which of course leads to voltage drops). So, I did the same thing on my new layout.
I never considered each mainline as a separate power district or dividing each mainline into several power districts. but, now, I can see where it makes good sense.
rrinker You'd need more PSX's, but if you put the boosters each in the middle of an 80' section of the mains, there's be 4x 40' bus lines coming from each - 40' in each direction for the #1 main, and 40' in each direction for the #2 main. At minimum I'd make each main it's own breaker section - so 2x PSX at each booster for the mains. Depending on the density of sidings and anticipated operation, perhaps 4x PSX at each booster - one for each 40' bus run, so each main loop would be divided into 4 sections.
You'd need more PSX's, but if you put the boosters each in the middle of an 80' section of the mains, there's be 4x 40' bus lines coming from each - 40' in each direction for the #1 main, and 40' in each direction for the #2 main. At minimum I'd make each main it's own breaker section - so 2x PSX at each booster for the mains. Depending on the density of sidings and anticipated operation, perhaps 4x PSX at each booster - one for each 40' bus run, so each main loop would be divided into 4 sections.
rrinker The other factor is where the reverse loops are - the PSX-AR wants a direct feed from the booster. If you are going to have to run an 80' bus from one of the new booster locations out to the PSX-AR, you're right back where you started. There's little point, and more complication, putting a PSX-AR downstream from a PSX.
The other factor is where the reverse loops are - the PSX-AR wants a direct feed from the booster. If you are going to have to run an 80' bus from one of the new booster locations out to the PSX-AR, you're right back where you started. There's little point, and more complication, putting a PSX-AR downstream from a PSX.
My layout is currently divided into seven power districts (three PSX and four PSX-AR), five of which are powered from one booster, while the remaining two power districts are powered from the other booster. If I move one booster to the other end of the layout, I will have to decide how to redistribute the power districts.
Because of the length of the two mainlines (160' each), I am considering making the west end of the mainlines one power district and the east end of the mainlines a second power district. The west end power district would be under one booster and the east end power district would be under the other booster.
But, I wonder if that makes sense to have the mainlines divided into two booster districts. A short one end of the layout would not prevent locos on the other end of the layout from continuing to run while the short remains unresolved. Any thoughts?
gregc does that mean putting a 2nd booster on the opposite side of the layout?
does that mean putting a 2nd booster on the opposite side of the layout?
gregc i'm guessing this isn't the case and there is an electrical connection (e.g. track) between the two end of the black lines
i'm guessing this isn't the case and there is an electrical connection (e.g. track) between the two end of the black lines
richhotrain gregc i think it would make a big difference is the booster connects to opposite ends of the track. greg, not sure I understand that second sentence?
gregc i think it would make a big difference is the booster connects to opposite ends of the track.
i think it would make a big difference is the booster connects to opposite ends of the track.
greg, not sure I understand that second sentence?
if the black lines in your diagram indicate trackage and the red line wires between the booster and track, your diagram suggests the track is disconnected near the booster and that the booster is connecting to opposite ends of the track.
rrinker 2 40' sections with the booster in the middle is always going to be better than a single 80' long section with the booster at one end. 40 feet of wire will have half the losses of 80 feet of wire. If you use an absolute maximum bus length of 50' - with 2 booster, you could run 200 linear feet of layout with no bus line more than 50'. Maximum coverage with minimum bus length. Always bet practice. --Randy
2 40' sections with the booster in the middle is always going to be better than a single 80' long section with the booster at one end. 40 feet of wire will have half the losses of 80 feet of wire.
If you use an absolute maximum bus length of 50' - with 2 booster, you could run 200 linear feet of layout with no bus line more than 50'. Maximum coverage with minimum bus length. Always bet practice.