GP-38 Dynamic Brakes are not working properly.

[StratPlayer62]

For one, when the dynamic brakes are active the amp meter on the control stand is going the wrong way, it moves into the power section, not braking.

The other thing I've noticed, notches 1-5 there is pretty much no braking at all, then when you go to 6 it starts to work, then 7 it maxes out right away and the brake warning light comes on, the whole range is only working from 6-8 instead of 1-8 like it should be. I've pretty much only driven the GP-38 so far, so I haven't tested this on the other 2 locos.

Is anyone else seeing this or know if it is a know problem? I wish there were a list of known problems somewhere.

[MessedThatUp]

I've been having this problem with the 38.

[Yerolo]

The SD40 also has the same issue. The dashboard and controls for the GP38 and SD40 are very similar, so I just put it down to me doing something wrong.

I can confirm the AC4400 brakes on all levels though. The AMP meter on the AC jumps up to about 38A once you have the dynamic brake in Setup (after being in idle for about 10secs)

[StratPlayer62]

Does Dovetail watch this forum for stuff like this or should we submit a ticket?

[Rudolf Jan]

Originally posted by StratPlayer62:

Does Dovetail watch this forum for stuff like this or should we submit a ticket?

Submit a ticket please.

[Arnstein86]

I can't say I've noticed that. I use the dynamic brake to maintain speed control in descents, isn't it that what it is for? From 0-0.8 % I usually set the brake from 2-5, 1.0-1.5 % from 5 upwards to 7. I look at the acceleration meter to tell how high I have to set it to maintain my speed, set it lower to increase - higher to lower speed. If you are in steep descents you may have to use autobrake in addition to dynamic to be able to slow down fast enough.

[SteakOplomb]

Il also noticed that on all locos, the dynamic brakes don't scale up correctly. Close to no braking power until you reach mid-position of the lever. Past this point, braking power increases exponentially, making fine adjustments very difficult.

[LeadCatcher]

I noticed the same thing on the meter that it shows power versus braking - not sure how effective the dynamic brakes are on the real locomotives - but understand there is a difference between different classes - but feel the SD40 and GP38 are off the mark in the lower settings as mentioned.

[Cowboy]

When you use dynamic brakes you have too put the trottle on zero 0

[LeadCatcher]

Yes -- since you are using the motors as generators basically - you have to stop providing power for them to work -- if you read the warning sign in the cab - it states to wait 10 seconds after bringing the throttle to idle before moving the dynamics to the "Set-up" position -- you must allow the system time to switch in set-up then move on to the different levels of Dynamic braking

[Eldrick]

They worked ok for me last night, Throttle to zero and I kept a steady 24mph down th 1.5%

[wolfe]

Throttle to Zero, then put dynamic brakes into setup mode, wait till you see a reading on the amps, as soon as it show 10 amps you can use them for slowing you down, its worked ok for me doing this

Edit Corrected

[Fjordland]

Originally posted by wolfe:

The reason it show amps is because you are still putting amps into the motors but with reverse polarity, so it will still show an amp reading, the more amps go in the more it wants to stop the motors from turning

No, the motors are turned into generators. The amperage reading is the amount generated and bled off through a resistor bank.

[wolfe]

Originally posted by Depth:

Originally posted by wolfe:

The reason it show amps is because you are still putting amps into the motors but with reverse polarity, so it will still show an amp reading, the more amps go in the more it wants to stop the motors from turning

No, the motors are turned into generators. The amperage reading is the amount generated and bled off through a resistor bank.

Your right, got confused on that bit, sorry

[Enrike_Hamalia]

The point is NOT how to use the Dynamic's, it's the fact that the Dynamic's don't seem to be working properly. I've also noticed the Dynamic brake on the SD40-2 working as explained above (With 1-5 providing almost no braking power, and barely registering on the "Amp'o'meter"(for lack of a better term) and 6-8 jumping exponentially in braking force.

Why is it doing this, and is it a bug, or is it supposed to work like that?

[SupaNerdo]

I understand how dynamic brakes work. I too had issues with the GP-38 going downhill with incorrect reading on the hud, but the brakes themselves worked for my purposes. (I did notice that the braking gets fierce at notch 7 and 8, but I don't know if that is realistic or not)