Oct. 2 Thread Followup Test Results (MRC Tech 2 + Atlas Tman + Bmann)

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D

DougC

Member
All:

Attn: Larry

Regarding my thread of October 2, “MRC Tech 2 + Atlas Tman + Bmann = Peculiar Situation”, concerning the Atlas Trainman GP38-2s causing my MRC Tech 2 Railmaster 2400 power packs to heat up to “too hot to touch” temperatures when run on regular power for 30 to 40 minutes, but when run on pulse power the power pack just heated up to hot (that takes about 30 minutes.) The Atlas Trainman RS36s got the power pack pretty hot on regular power, but the Bachmann engines would only heat the power packs up minimally on either regular or pulse power.

All are run on straight DC (no DCC).

All my 5 loops (each with a separate power pack) have been direct-wired from power packs to tracks with #22 solid copper wire (with a silver-colored coating).

After reading the comments and advice in the previous thread, what I have done is:

A. Purchased some #16 gauge stranded copper wire and installed it as a buss wire for only Track #1 (outermost loop) [Radio Shack $20 for roll of 100’ double-wire, brown (speaker wire)] and removed all the old #22 gauge wire except for short track feeders

B. Purchased online a 0-3 amp DC ammeter and a 0-15 volt DC voltmeter [from Allied Electronics, Shurite brand, about $17 each], installed them, and have since used them on Track #1 and then Track #2 (separately)

C. Tested Trk#1 and Trk#2 separately with no load on with the two meters. The ammeter shows nothing at all so no hidden shorts on either

Track #1’s train has 63 cars, 22” radius; Track #2’s train has 51 cars, 19” radius; both loops are about 50’ long each.

After running (all in pairs) Atlas Trainman GP38-2s, RS36s, Bmann SD40-2s, GP30s, and FTA/B on Track #1 (buss-fed with with the #16 stranded copper wire plus about 5 #22 feeders), and Track #2 (all fed direct at about 5 points with #22 solid copper wire) here’s what I’ve found:

ALL engine PAIRS when run between 25 to 55 mph on the power pack speed scale in PULSE MODE showed between .25 to .5 amps each, 3 to 6 volts each.

ALL engine PAIRS when run between 25 to 50 mph on the power pack speed scale in REGULAR MODE showed between .3 to .5 amps each, 4 to 6 volts each.

All of these amp and volt readings above seem fine to me; nothing sticks out (or did I miss something?).

Conclusions:

1. The wiring (using #16 stranded with feeders vs. all #22 solid direct) doesn’t make any basic difference in current draw. This surprised me.

2. The Atlas Trainman GP38-2s and to a certain extent the Atlas Trainman RS36s got the MRC power packs’ surfaces too hot to touch in regular power mode no matter on Track #1 or Track #2. And the heat level went way down when I used pulse power on either track. Again the track wiring doesn’t make any difference.

3. The Bachmann engines run normally on either regular or pulse power, but they do keep the power packs’ surfaces less warm when run in pulse mode.

4. Based on all of this, plus the fact the my LHS was having trouble selling his Atlas Trainman engines (he had to keep marking the prices down), I’m guessing they are “dumbed- down” or non-straight-DC-friendly motors in these lower-end models and that they are therefore somewhat electronically hostile to at least some power packs. (I don’t have any of the “high end” Atlas engines to test.)

NOTE: This tentative conclusion about the Trainman motors is similar to my experience with their headlights on these models; the lights only turn on when the power pack speed setting is over 30mph or can they be programmed in DCC to come on immediately. In other words, the headlights and maybe the motors (and other aspects?) of Atlas’ locos are getting less and less straight-DC friendly and may eventually not operate at all on straight-DC.]

5. I still like and will continue to use (in pulse power only) the Atlas Trainman engines.

Do any you have any thoughts about this? Were these tests in any way helpful to you? I myself have learned a good bit.

DougC
 
Aren't the Trainman engines using the internal parts of the regular Atlas line? They just have less cosmetic features on the shells??
 
I would call MRC and talk to a service tech to see what they say. If may be the fault of the power pack. I have found them to be very helpfull.

Bob
 


I would contact Atlas. I know they are having a problem with the new "Genset" locomotives, which are Trainman variations and the MRC Tech 6 power packs. Possibly there is some connection?
 
The trainman locomotives use the same motor and drive as the master series with one exception, the flywheels are smaller.

Atlas's jumper plug contains a resistor across the motor pins which allows the locomotive to be operated on DC, but will be seen as a short on a DCC system if no decoder is installed. Atlas was tired of people sending them models with burnt out motors for repair due to the AC current from the DCC systems destroying them. If you have an 8-pin jumper plug from a BLI locomotive or something, you may want to swap it with the Atlas one. That may stop your power pack from overheating.

The Atlas genset blows its capacitors when used with an MRC tech 6 power pack. The capacitors are unnecessary on DC or DCC and should be removed. The capacitors are very large (too large in fact).
 
Let me say up front I am NOT an electrical expert. I am assuming that the resistor across the motor pins which acts as a short causes the DCC system to shut down before the motor can be damaged. Why would you want to remove the resistor from the Genset? Isn't it protecting the motor from being damaged?
 
My apologies for not making myself clearer. I was speaking in general terms about the resistor set up and not in relation to this topic. I should have said I was going off topic so I didn't create confusion.
 
Well, you would WANT to remove the resistor if you are installing a decoder. You'll also want to remove the two large capacitors hidden under the weight. They interfere with DCC operation and on MRC Tech 6 power packs, they explode!
 


Thanks for the information. Do the capacitors you mentioned under the weight exist in the regular Trainman locomotives as well and do they need to be removed to install DCC in these locomotives as well? I have a couple of RS32/36's that I want to put decoders in sometime.
 
DougC said:
All:


All are run on straight DC (no DCC).

All my 5 loops (each with a separate power pack) have been direct-wired from power packs to tracks with #22 solid copper wire (with a silver-colored coating).

After reading the comments and advice in the previous thread, what I have done is:

A. Purchased some #16 gauge stranded copper wire and installed it as a buss wire for only Track #1 (outermost loop) [Radio Shack $20 for roll of 100’ double-wire, brown (speaker wire)] and removed all the old #22 gauge wire except for short track feeders

B. Purchased online a 0-3 amp DC ammeter and a 0-15 volt DC voltmeter [from Allied Electronics, Shurite brand, about $17 each], installed them, and have since used them on Track #1 and then Track #2 (separately)

C. Tested Trk#1 and Trk#2 separately with no load on with the two meters. The ammeter shows nothing at all so no hidden shorts on either

Track #1’s train has 63 cars, 22” radius; Track #2’s train has 51 cars, 19” radius; both loops are about 50’ long each.

After running (all in pairs) Atlas Trainman GP38-2s, RS36s, Bmann SD40-2s, GP30s, and FTA/B on Track #1 (buss-fed with with the #16 stranded copper wire plus about 5 #22 feeders), and Track #2 (all fed direct at about 5 points with #22 solid copper wire) here’s what I’ve found:

ALL engine PAIRS when run between 25 to 55 mph on the power pack speed scale in PULSE MODE showed between .25 to .5 amps each, 3 to 6 volts each.

ALL engine PAIRS when run between 25 to 50 mph on the power pack speed scale in REGULAR MODE showed between .3 to .5 amps each, 4 to 6 volts each.

All of these amp and volt readings above seem fine to me; nothing sticks out (or did I miss something?).

Conclusions:

1. The wiring (using #16 stranded with feeders vs. all #22 solid direct) doesn’t make any basic difference in current draw. This surprised me.

2. The Atlas Trainman GP38-2s and to a certain extent the Atlas Trainman RS36s got the MRC power packs’ surfaces too hot to touch in regular power mode no matter on Track #1 or Track #2. And the heat level went way down when I used pulse power on either track. Again the track wiring doesn’t make any difference.

3. The Bachmann engines run normally on either regular or pulse power, but they do keep the power packs’ surfaces less warm when run in pulse mode.

4. Based on all of this, plus the fact the my LHS was having trouble selling his Atlas Trainman engines (he had to keep marking the prices down), I’m guessing they are “dumbed- down” or non-straight-DC-friendly motors in these lower-end models and that they are therefore somewhat electronically hostile to at least some power packs. (I don’t have any of the “high end” Atlas engines to test.)

NOTE: This tentative conclusion about the Trainman motors is similar to my experience with their headlights on these models; the lights only turn on when the power pack speed setting is over 30mph or can they be programmed in DCC to come on immediately. In other words, the headlights and maybe the motors (and other aspects?) of Atlas’ locos are getting less and less straight-DC friendly and may eventually not operate at all on straight-DC.]

5. I still like and will continue to use (in pulse power only) the Atlas Trainman engines.

Do any you have any thoughts about this? Were these tests in any way helpful to you? I myself have learned a good bit.

DougC
Click to expand...

Doug, I don't know what to say about you still having problems w/all of your throttles still getting hot. What is "Pulse Power" on your throttles, since I don't have any of that on any of my MRC powerpacks.
You are running 50 ft. lengths of wire from your transformers all the way to the end of the track. When you say you have 4 mainlines w/seperate transformers to each track, are all of the transformers the same size?
If you have 4 seperate mainlines, then you have 8 Buss wires, is this correct?
I'm still trying to figure out why all this overheating in your power supplies.
 
All:

Thank you all for your responses. My post seems to have opened up a sort of “can of worms” that goes from the Trainman locos to the new Gensets’ locos, but we we’ll see if I can sort some things out here.

Jayl1 – looks like diburning answered your question about Trainman locos for us in the positive – Atlas locos use the same drivetrain and motors. I didn’t know they used the same motors, hence my guess at a lower quality motor in the Trainman series.

Bobwrgt – a good suggestion. I plan to call MRC tech support; they might have some knowledgeable input (in addition to what’s on this thread.)

ALCOS4EVER – I might try to contact Atlas – don’t seem to have much success (i.e. no response) whenever I do.

No problem on the hijack; diburning gave some good info on the Atlas Gensets and MRC’s Tech 6s.

Diburning – thanks for the info on Trainman motors and drivetrains being the same as Atlas’ better models.

If I can figure out what the Atlas’ jumper plug is and can take it to Radio Shack or to someone who knows what the resistor is, if I can cut it’s connection at one end to disable it I’d be willing to try that. Do you think that’s doable? I don’t think I have any other jumper plugs (and I’ll admit I don’t know what they look like.)

Diburning, I just had a thought and a question for you. I have read that if a person is using just DC you can remove Bachmann’s DCC boards in their engines, direct-wire the motor and some headlight LEDS, and this will eliminate the motor hum and not affect performance. I’ve been doing this and it has worked. Well, if I remove Atlas Trainman’s GP38-2s DCC boards that would get rid of the resistor and its jumper plug wouldn’t it? And if so I don’t think there would be any downside, and I could then retest a couple of locos and post the results. What do you think? Thanks.

IowaFarmBoy – from this MissouriHillBilly - I’ve never tried running one singly; I’ll have to do that to see if it heats up the power pack. Thanks. If it doesn’t that tells me that the load it pulls has something to do with heating up the power pack.

Larry: Per your reply (quoted below) -

“Doug, I don't know what to say about you still having problems w/all of your throttles still getting hot. What is "Pulse Power" on your throttles, since I don't have any of that on any of my MRC powerpacks.
You are running 50 ft. lengths of wire from your transformers all the way to the end of the track. When you say you have 4 mainlines w/seperate transformers to each track, are all of the transformers the same size?
If you have 4 seperate mainlines, then you have 8 Buss wires, is this correct?
I'm still trying to figure out why all this overheating in your power supplies.”

First, diburning might have the answer to the power pack overheating. It may be in that resistor in the jumper plug, that is, in the loco itself. Working on that (see above, especially the larger type paragraph with the question for diburning.)

As for what Pulse Power is I’d have to go on the net and find a technical description (that I probably wouldn’t understand.) It’s of course obviously a different type of power than “regular.”

All my power packs are identical, and each has its own loop to control.

Except for Track #1 that now has its own #16 stranded copper wire buss (and short #22 track feeds), the other four loops don’t have buss wires. Each of these four has #22 solid copper wire going from each power pack, thru some slide and rotary switches, to various points (about 5 per loop) by the most direct route (looks haphazard) under the layout. I’d say the longest distance is about 15’.

Because of the testing done on the track that has the proper buss wire and a track that has no proper buss wire but the “sloppy” #22 wire, and the fact that the Trainman engines heat up on either (and on any other of my tracks,) that tells me the problem is in the locos and not the track (at least so far; IowaFarmBoy’s suggestion - run the loco by itself with no load - may show something.)

Wright2626 – I’ll admit I don’t know how to measure resistance from positive to ground. Does this mean measuring something across the motor? If so might this have something to do with a resistor in the jumper plug per diburning above? Can a person measure this resistance with an ammeter or voltmeter?

I sort of figured that measuring the amps on various locos on two differently-wired track loops (one with good buss and the other wired sort of haphazardly), might show some resistance of some type or other through significant variations in amp readings. Since there were no significant variations in reading, and they were all what I would call low, I’m guessing the resistance is therefore minimal (but this may not be what you’re talking about.)
 
The jumper plug jumps the leads together, the pickup to motor to pickup and headlights to motor.

You CAN wire the loco up without the circuit board. However, you will need resistors for the LEDs if the original resistors were on the circuit board and wired to the leads. Athearn Blue Box locomotives had no wires at all.

If you are careful, you can snip the resistor off of the Atlas jumper plug with no problems (I've never had to since I run DCC)
 
I'm no electronics expert, but its my understanding that pulse width modulation technology generally causes heat build up in DC motors. I also think DCC decoders prefer PWM as their source of DC power. I also know that in the early stages of DCC, decoder overheating was a big issue, even so much as modelers punching out the windows in the cabs to get some airflow under the shell, so I'm told. PWM may even cause a hum in dual mode decoders at low speeds.

It sounds like Atlas is designing their boards to prevent excessive heat build up going to their motors and any decoder that may get plugged into the circuit board. That heat may get transferred back to your power pack during pulse mode. Whereas, the Bachmann's may not have that protection built into their boards, a simpler less expensive board, which may also be causing a hum.

It would be interesting to know if the Bachmann locomotives' motors get hot while on pulse mode, and the Atlas locomotives stay cool.

As you know during our discussion of the TM headlights, I think Atlas has modified its circuit boards with the introduction of the 10000 series serial numbers.

It would also be interesting to know if older versions of TM's, with the 4-digit serial numbers, cause the same problem with your power pack.
 


it just sounds like the atlas engines have more resistance than your other engines. voltage=ampsxresistance. if you are running at 6 volts, and using 1 amp, your resistance would be 6 ohms. if you are running 6 volts at 0.5 amps, your resistance has to be 12ohms. the power pack has to work harder to get the current flowing. if that makes any sense. so, if you were able to bypass the board than the power pack should run cooler.
 
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