Maggie’s Motivational Pic Thread v2.0 - - New Rules - See Post #1
- Thread starter Snake-Eyes
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- motivational pictures
Yes @akmike47 is having a cold cranking amp issue.Battery life.
You want me to talk about battery life now ?
I could have a dildo and not use it on myself, maybe I'm just a giving lover you pricks!
Well I'm the king of the Poors so....Well, he should buy the biggest AGM he can afford.........
Well wash it and give it back.
Thank you.Well, you have to make sure what control conditions you are specifying. Assuming that the motor is sized for the load properly and it is being started" Across the Line" (Via an AC, Three Phase Contactor), the general rule of thumb (there are many exceptions however) is 600 to 800 percent inrush current (of Motor nameplate/rated current) and approximately 250 % starting torque. When starting the motor Across the Line, the Motor should come up to "Base Speed" (the Motor's nameplate rated RPM) quickly (as in just a few seconds), otherwise, you run the distinct risk of burning it out (very quickly).
If the Motor is designed/manufactured/applied as an AC "Vector" Motor and is connected to an AC "Vector" Drive, yes, you can get up to 250% torque from the motor (intermittently) from zero to base speed of the Motor, assuming the Vector drive has enough current (on an overload/intermittent basis) to supply the motor. The Vector Motor/Drive combination is known as "Constant Torque". In the context of Constant Torque, the general rule of thumb is that the Motor can/will deliver 100% torque "Constantly" anywhere from zero speed, throughout the (Base Speed) speed range, all the way up to Base Speed. The most common Three Phase AC Motors are 4 Pole and are rated between 1725 RPM and 1795 RPM, depending on the size of the motor. The larger the Motor (into the Hundreds/Thousands of Horsepower), the lower the Slip, hence the higher the Base Speed RPM. 100% continuous torque indicates a properly applied Vector Motor/Drive combination. Above Base Frequency/Speed (of the Motor) the Motor's torque capacity falls off, due to the Vector Drive no longer having any more DC Link voltage available to force more current into the motor. This is why you will never see AC Vector Motor/Drives on Elevators set up to go beyond the Motor's rated Speed/Frequency. Going above Base Speed on an Elevator (Vector) Motor/Drive combination is not done because you lose braking capacity the higher you go above base speed.
Conversely, with the Vector Motor/Drive combination, it's "watts in/watts out. So, if you are starting from a low or zero speed, the voltage applied to the Motor is very low, but the current can be as high as the Vector drive is capable of delivering (on either a continuous or overload basis. This is why most Vector Motors are supplied with full speed, separately powered blowers on the back of them). As a result, upon startup, the Motor can be producing large amounts of torque (due to the current capacity of the Vector Drive), but the line current going into the Vector Drive will be very low, nowhere remotely close to what the Vector drive is providing to the Vector Motor.
As far as the Inertia/Torque comment above. No, Inertia is not Torque. They are two distinctly different terms.
Inertia;
"Inertia is the resistance of any physical object to a change in its velocity. This includes changes to the object's speed, or direction of motion".
Inertia - Wikipedia
en.wikipedia.org
Think of a Flywheel (or the main Wheels/Rollers on a Dyno). It has a distinct characteristic of Inertia. Regardless of rotational speed (low speed, high speed, direction, etc.) the Flywheel has no "Torque" of it's own. It is only when you try to change the Flywheel's Speed that Torque is required to do so. (Actually, at a constant speed, a little bit of Torque is required to overcome the effects of windage and friction of the Flywheel). When a Speed/Direction change is required, it is Torque (provided by the Motor) that acts upon the Flywheel and it's associated Inertia. For a given amount of inertia, it takes more Torque (and Vector Drive Current) to effect a rapid rotational speed change than it does for a more gradual (slower/lower rate of)speed change.
Signed,
A 35 year Veteran of the Motor/Drive/Power Electronics Industries.
You have infinitely more patience than I.
Oh hell, that just beggin' to be restored! I wish I had the money and expertise to restore that.
Engine builder here. Horsepower is measure of how fast an engine can work. So, its a measure of how fast it can move things. Some dynos only measure horsepower. It is figured by how fast they can get the heavy rollers to accelerate.
Holy shit! I've been driving for 30+ years and could never figure that out!
Chuckle... are we still arguing Torque/HP? Yes, Torque is needed, as it is *part* of the equation. Is it king? No.
I have a car I take to the track (the type with twisty curves, and not just a straight line) and it only produces 145 Foot Pounds of Torque.
None of the big V8 cars stay with me 0-60. Now, the car body is designed to produce downforce, so its CDA (drag) is as bad as a minivan. Once I am over 60 MPH, then overcoming the drag consumes a lot of force/energy... and the V8 cars gain ground. Once we get back into the twisties, they get passed.
You cannot discuss the importance of Torque/HP, unless you includes Mass and Drag. A really light car, needs less Torque/HP to accellerate quickly at low speeds (example Lotus), a car with low drag, requires less Torque/HP to achieve a high rate of speed (example 280z, they had very good top-end speed for their given HP/Torque).
You must consider the whole package, to have a meaningful discussion.
I have a car I take to the track (the type with twisty curves, and not just a straight line) and it only produces 145 Foot Pounds of Torque.
None of the big V8 cars stay with me 0-60. Now, the car body is designed to produce downforce, so its CDA (drag) is as bad as a minivan. Once I am over 60 MPH, then overcoming the drag consumes a lot of force/energy... and the V8 cars gain ground. Once we get back into the twisties, they get passed.
You cannot discuss the importance of Torque/HP, unless you includes Mass and Drag. A really light car, needs less Torque/HP to accellerate quickly at low speeds (example Lotus), a car with low drag, requires less Torque/HP to achieve a high rate of speed (example 280z, they had very good top-end speed for their given HP/Torque).
You must consider the whole package, to have a meaningful discussion.
Does all this drivel really have to be in the MPV thread? Without any pictures or video? Why don’t you all just start a thread about it, on a car forum, where it belongs? Sheesh! Three pages of Dick swinging and braggadocios, along with a little bit of actual good information, interspersed with the occasional attempt by someone with a a clear head trying to get the thread back on track.
For Fucks’ Sake already!
Idiots arguing about model cars and boats in a motivational picture/video thread on a precision rifle forum. See below:
For Fucks’ Sake already!
Idiots arguing about model cars and boats in a motivational picture/video thread on a precision rifle forum. See below:
I don’t see kitties, bubbles is out of the deal.
Shut it down for today; you win
- Nov 3, 2010
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Or dancing with some marines
