Locomotive electrical output

[Anonymous]

88,000 lbs at $0.50 a pound thats $44,000 dollars!!! We should go in the scrapper business. Buy up all the old engines at about $10,000 a piece, hire some homeless people to tear them apart. (Pay them in booze and provide them with a new refrigerater box) Thats good profit. Not to mention the scrap steel. Sounds better everytime I read it.
TIM A

[Anonymous]

88,000 lbs at $0.50 a pound thats $44,000 dollars!!! We should go in the scrapper business. Buy up all the old engines at about $10,000 a piece, hire some homeless people to tear them apart. (Pay them in booze and provide them with a new refrigerater box) Thats good profit. Not to mention the scrap steel. Sounds better everytime I read it.
TIM A

[dfandrews]

Info to stump your friends with:
According to a copper industry publication, there is about 88,000 lbs. of copper in a GE 9-44CW.

[dfandrews]

Info to stump your friends with:
According to a copper industry publication, there is about 88,000 lbs. of copper in a GE 9-44CW.

[Anonymous]

Dekemd, Oltmannd,Zardoz and pfrench68 that gentlmen was a excellent job in explaining a complicated subject. I am very impressed with the talent on this WEB site.
TIM A

[Anonymous]

Dekemd, Oltmannd,Zardoz and pfrench68 that gentlmen was a excellent job in explaining a complicated subject. I am very impressed with the talent on this WEB site.
TIM A

[dekemd]

QUOTE: Originally posted by teddyA

QUOTE: Originally posted by oltmannd

When starting a train, you want lots of pulling force. Pulling force is proportional to the current flowing thru the traction motors. If each motor can take 900 Amps and I put them all in parallel, I'd need a main gen that can do 5400 Amps! Meltdown city! If I put them all in series, I only need 900 Amps, but I'd need to do it a6 times the voltage of having them all in parallel

As a traction motor turns, it create "back EMF" or a voltage that opposes the voltage imposed on it. The faster it turns, the higher this back voltage gets. In order to keep the motors taking the same HP, I need to raise the voltage on them higher than the back EMF. Lets say, at 60 mph I need 900 VDC at full throttle. If I arrange my 6 traction motors in parallel, I'd need a generator that can do 6000 Volts. Flashover City! If I arrange them in parallel, I only need 900 volts (but 6 times the current).

Please clarify the bolded section, in parallel, they would need 6000volts, but in parallel, you'd need 900 volts but 6 times the current?

It should read "If I arrange my 6 traction morors in SERIES, I'd need a generator that can do 6000 volts..... If I arrange them in parallel, I only need 900 volts (but 6 times the current).

Derrick

[dekemd]

QUOTE: Originally posted by teddyA

QUOTE: Originally posted by oltmannd

When starting a train, you want lots of pulling force. Pulling force is proportional to the current flowing thru the traction motors. If each motor can take 900 Amps and I put them all in parallel, I'd need a main gen that can do 5400 Amps! Meltdown city! If I put them all in series, I only need 900 Amps, but I'd need to do it a6 times the voltage of having them all in parallel

As a traction motor turns, it create "back EMF" or a voltage that opposes the voltage imposed on it. The faster it turns, the higher this back voltage gets. In order to keep the motors taking the same HP, I need to raise the voltage on them higher than the back EMF. Lets say, at 60 mph I need 900 VDC at full throttle. If I arrange my 6 traction motors in parallel, I'd need a generator that can do 6000 Volts. Flashover City! If I arrange them in parallel, I only need 900 volts (but 6 times the current).

Please clarify the bolded section, in parallel, they would need 6000volts, but in parallel, you'd need 900 volts but 6 times the current?

It should read "If I arrange my 6 traction morors in SERIES, I'd need a generator that can do 6000 volts..... If I arrange them in parallel, I only need 900 volts (but 6 times the current).

Derrick

[Anonymous]

QUOTE: Originally posted by oltmannd

When starting a train, you want lots of pulling force. Pulling force is proportional to the current flowing thru the traction motors. If each motor can take 900 Amps and I put them all in parallel, I'd need a main gen that can do 5400 Amps! Meltdown city! If I put them all in series, I only need 900 Amps, but I'd need to do it a6 times the voltage of having them all in parallel

As a traction motor turns, it create "back EMF" or a voltage that opposes the voltage imposed on it. The faster it turns, the higher this back voltage gets. In order to keep the motors taking the same HP, I need to raise the voltage on them higher than the back EMF. Lets say, at 60 mph I need 900 VDC at full throttle. If I arrange my 6 traction motors in parallel, I'd need a generator that can do 6000 Volts. Flashover City! If I arrange them in parallel, I only need 900 volts (but 6 times the current).

Please clarify the bolded section, in parallel, they would need 6000volts, but in parallel, you'd need 900 volts but 6 times the current?

[Anonymous]

QUOTE: Originally posted by oltmannd

When starting a train, you want lots of pulling force. Pulling force is proportional to the current flowing thru the traction motors. If each motor can take 900 Amps and I put them all in parallel, I'd need a main gen that can do 5400 Amps! Meltdown city! If I put them all in series, I only need 900 Amps, but I'd need to do it a6 times the voltage of having them all in parallel

As a traction motor turns, it create "back EMF" or a voltage that opposes the voltage imposed on it. The faster it turns, the higher this back voltage gets. In order to keep the motors taking the same HP, I need to raise the voltage on them higher than the back EMF. Lets say, at 60 mph I need 900 VDC at full throttle. If I arrange my 6 traction motors in parallel, I'd need a generator that can do 6000 Volts. Flashover City! If I arrange them in parallel, I only need 900 volts (but 6 times the current).

Please clarify the bolded section, in parallel, they would need 6000volts, but in parallel, you'd need 900 volts but 6 times the current?

[zardoz]

Mook-
You ask such interesting questions that to me you seemed like the type of person that was not only interesting, but interested in the world around them.

[zardoz]

Mook-
You ask such interesting questions that to me you seemed like the type of person that was not only interesting, but interested in the world around them.

[Mookie]

Mookie's mind hasn't a clue what you are talking about.....

[Mookie]

Mookie's mind hasn't a clue what you are talking about.....

[zardoz]

FYI-
The following info comes from a website known as "Howstuffworks", a really cool site that has lots to offer inquiring minds-like Mookie's.

19. What is shunting? As the speed of a locomotive increases, the traction motors generate large amounts of extra electricity that is simply not needed. This creates resistance in the motors (called counter-emf) and reduces the amount of amperage going into the motors, which limits speed. Shunting is a process in which the resistance is reduced by lowering the flow of electricity to the magnets that create the EM field in the motors without reducing the amperage. This lowers the resistance the traction motors face. (Think of shunting as like shifting gears in a car)

20. What is transition? A procedure that reduces the resistance the traction motors (see shunting) face by changing the proportion of amperage and voltage while not changing the output of the alternator. This reduces counter-emf. This allows the locomotive to develop more amperage and volts as needed. Transition may cause a brief interruption in tractive effort and can result in a broken coupler if slack develops and then the cars snap back as TE resumes. (Think of transition as like shifting gears in a car)

21. Do all locomotives have transition and shunting? No.

[zardoz]

FYI-
The following info comes from a website known as "Howstuffworks", a really cool site that has lots to offer inquiring minds-like Mookie's.

19. What is shunting? As the speed of a locomotive increases, the traction motors generate large amounts of extra electricity that is simply not needed. This creates resistance in the motors (called counter-emf) and reduces the amount of amperage going into the motors, which limits speed. Shunting is a process in which the resistance is reduced by lowering the flow of electricity to the magnets that create the EM field in the motors without reducing the amperage. This lowers the resistance the traction motors face. (Think of shunting as like shifting gears in a car)

20. What is transition? A procedure that reduces the resistance the traction motors (see shunting) face by changing the proportion of amperage and voltage while not changing the output of the alternator. This reduces counter-emf. This allows the locomotive to develop more amperage and volts as needed. Transition may cause a brief interruption in tractive effort and can result in a broken coupler if slack develops and then the cars snap back as TE resumes. (Think of transition as like shifting gears in a car)

21. Do all locomotives have transition and shunting? No.

[oltmannd]

QUOTE: Originally posted by adrianspeeder

oltmannd, thanks a lot
I am going to be an electrical engineer, so this topic is interesting to me. Every time I asked someone I would get an answer like “I don’t know.” What you said makes sense to me, and that’s one less question in my mind.
Do you know what type of wire is used between the main generator and the traction motors?
Thanks,
Adrian

Big. Copper. Lots of 0s in the gauge. With synthetic rubber insulation. The builders messed around using aluminum for a while in the late 60s - early 70s, but it caused lots of fires.

[oltmannd]

QUOTE: Originally posted by adrianspeeder

oltmannd, thanks a lot
I am going to be an electrical engineer, so this topic is interesting to me. Every time I asked someone I would get an answer like “I don’t know.” What you said makes sense to me, and that’s one less question in my mind.
Do you know what type of wire is used between the main generator and the traction motors?
Thanks,
Adrian

Big. Copper. Lots of 0s in the gauge. With synthetic rubber insulation. The builders messed around using aluminum for a while in the late 60s - early 70s, but it caused lots of fires.

[dekemd]

oltmannd,

After thinking about it last night, that was the reason I came up with. Thanks for the great explanation. I had the concept figured out, just didn't know how to explain it.

Derrick

[dekemd]

oltmannd,

After thinking about it last night, that was the reason I came up with. Thanks for the great explanation. I had the concept figured out, just didn't know how to explain it.

Derrick

[adrianspeeder]

oltmannd, thanks a lot
I am going to be an electrical engineer, so this topic is interesting to me. Every time I asked someone I would get an answer like “I don’t know.” What you said makes sense to me, and that’s one less question in my mind.
Do you know what type of wire is used between the main generator and the traction motors?
Thanks,
Adrian

[adrianspeeder]

oltmannd, thanks a lot
I am going to be an electrical engineer, so this topic is interesting to me. Every time I asked someone I would get an answer like “I don’t know.” What you said makes sense to me, and that’s one less question in my mind.
Do you know what type of wire is used between the main generator and the traction motors?
Thanks,
Adrian

[zardoz]

oltmannd-
very interesting. thanks

[zardoz]

oltmannd-
very interesting. thanks

[oltmannd]

Transition is a way of matching the locomotive's performance needs to the abilities of the main generator. The main generator has a current limit and a voltage limit inherent in it's design. If required to produce too much current, the windings will get too hot (from their own internal resistance) and the insulation will melt and the generator will have shorted windings. If the voltage gets too high, either the commutator will flash over (DC generator) or the rectifying diodes with fail (AC "generator" a.k.a. alternator).

When starting a train, you want lots of pulling force. Pulling force is proportional to the current flowing thru the traction motors. If each motor can take 900 Amps and I put them all in parallel, I'd need a main gen that can do 5400 Amps! Meltdown city! If I put them all in series, I only need 900 Amps, but I'd need to do it a6 times the voltage of having them all in parallel

As a traction motor turns, it create "back EMF" or a voltage that opposes the voltage imposed on it. The faster it turns, the higher this back voltage gets. In order to keep the motors taking the same HP, I need to raise the voltage on them higher than the back EMF. Lets say, at 60 mph I need 900 VDC at full throttle. If I arrange my 6 traction motors in parallel, I'd need a generator that can do 6000 Volts. Flashover City! If I arrange them in parallel, I only need 900 volts (but 6 times the current).

Transition requires reconfiguration of how the motors are connected to the generator. This is usually done with some really big contactors and switches. Typically, a six axle will require two arrangements. All six in parallel or three pairs of two. Lately, (SD50/Dash8 and newer) transition takes place on the main generator. The generator has two sets of winding that are arranged in series or parallel by means of a single contactor (switch). This has made for much smoother transition.

Four axles since the GP40 are full parallel all the time. The reason an Amtrak F40 accelerates more slowly than a GP40-2 is most likely gear ratio. The Dash 2 control system is identical.

[oltmannd]

Transition is a way of matching the locomotive's performance needs to the abilities of the main generator. The main generator has a current limit and a voltage limit inherent in it's design. If required to produce too much current, the windings will get too hot (from their own internal resistance) and the insulation will melt and the generator will have shorted windings. If the voltage gets too high, either the commutator will flash over (DC generator) or the rectifying diodes with fail (AC "generator" a.k.a. alternator).

When starting a train, you want lots of pulling force. Pulling force is proportional to the current flowing thru the traction motors. If each motor can take 900 Amps and I put them all in parallel, I'd need a main gen that can do 5400 Amps! Meltdown city! If I put them all in series, I only need 900 Amps, but I'd need to do it a6 times the voltage of having them all in parallel

As a traction motor turns, it create "back EMF" or a voltage that opposes the voltage imposed on it. The faster it turns, the higher this back voltage gets. In order to keep the motors taking the same HP, I need to raise the voltage on them higher than the back EMF. Lets say, at 60 mph I need 900 VDC at full throttle. If I arrange my 6 traction motors in parallel, I'd need a generator that can do 6000 Volts. Flashover City! If I arrange them in parallel, I only need 900 volts (but 6 times the current).

Transition requires reconfiguration of how the motors are connected to the generator. This is usually done with some really big contactors and switches. Typically, a six axle will require two arrangements. All six in parallel or three pairs of two. Lately, (SD50/Dash8 and newer) transition takes place on the main generator. The generator has two sets of winding that are arranged in series or parallel by means of a single contactor (switch). This has made for much smoother transition.

Four axles since the GP40 are full parallel all the time. The reason an Amtrak F40 accelerates more slowly than a GP40-2 is most likely gear ratio. The Dash 2 control system is identical.

[zardoz]

I do not know too much about electrical matters other than what I learned when in locomotive class. I do know that locomotives use series to start moving, and around 20-25mph transitioned to parallel. On the GP30 and GP35 locomotives there were (if memory serves) about 20 transition steps, with the main one around 23mph. There was a series, series shunt, parallel, and parallel shunt on the E8 & E9 locomotives we used for suburban service. I do know that the F40PH locomotives do NOT have any transition steps, the result being that they are very slow off the line. They would be terrible units for suburban service except for the fact that they made up for the slow starting by virtue of good acceleration above 20mph. When starting a heavy train a locomotive can develop over 1500 amps per traction motor, even if the throttle might only be in 3rd or 4th notch. But at 50mph in the 8th notch a locomotive might only be pulling 300 amps. And in full dynamic braking each motor (SD40-2) can generate up to 900 amps of braking power.

[zardoz]

I do not know too much about electrical matters other than what I learned when in locomotive class. I do know that locomotives use series to start moving, and around 20-25mph transitioned to parallel. On the GP30 and GP35 locomotives there were (if memory serves) about 20 transition steps, with the main one around 23mph. There was a series, series shunt, parallel, and parallel shunt on the E8 & E9 locomotives we used for suburban service. I do know that the F40PH locomotives do NOT have any transition steps, the result being that they are very slow off the line. They would be terrible units for suburban service except for the fact that they made up for the slow starting by virtue of good acceleration above 20mph. When starting a heavy train a locomotive can develop over 1500 amps per traction motor, even if the throttle might only be in 3rd or 4th notch. But at 50mph in the 8th notch a locomotive might only be pulling 300 amps. And in full dynamic braking each motor (SD40-2) can generate up to 900 amps of braking power.

[dekemd]

Thanks guys. So we're talking in the 2.5 to 3 Megawatt range. That's what I wanted to know. But you did bring up another question. Tell me about the series to parallel transition. I understand series and parallel circuits. What I want to know is what advantages you gain by running the motors is series and then parallel.

Derrick