My friend is coming over with his beautiful old brass locos to run them for a bit. They are DC and so we run them with the DCC controller as a DC loco. However, I have felt in the past that it is best to remove all my DCC locos from the track while addressing the DC as loco 00 for the safety of the decoders. I forget why I have this in my mind.
Is removing my DCC locos a good precaution? This is a bit of a nuisance because I usually have a dozen or so out and tucked away in roundhouses, sidings etc. Thanks.
Hello All,
From what I'm understanding is that your DCC system can produced a "DC" signal for a given address. Similar to the Bachmann EZ-Command system; pg. 6.
The problem with the digital waveform, known as zero stretching from a DCC controller, is that if the DC loco is left idle on the track the analog (DC) motor might overheat to a catastrophic point.
If you are producing a zero stretching waveform your DCC motive stock should not be at risk.
However, if you are completely converting; changing track power sources from DCC to DC, I would recommend removing or isolating your DCC motive power.
Some decoders can handle both DCC and DC operation with the CV's correctly set. (See decoder manufacturers website for dual-function settings).
If the decoders are not set up for this you run the risk of blowing decoders. They will fry before the motor is damaged in this situation.
Keep in mind, any of the decoders that are setup for dual-function will also move when the DC throttle is applied.
Personally I would remove or isolate the DCC motive power and enjoy the operation of the DC brass locos.
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
jjdamnit However, if you are completely converting; changing track power sources from DCC to DC, I would recommend removing or isolating your DCC motive power. Personally I would remove or isolate the DCC motive power and enjoy the operation of the DC brass locos.
Rich
Alton Junction
Personally I would not run ANY DC engine using the address 00 zero stretching method. There's a reason current systems don't have this feature, and some engine manufacturers (Atlas for one) are installing small diodes on the dummy DCC plug to cause a small short if you attempt to run it on address 00.
I've heard of people doing it and having no trouble and I've also seen engines literally have a melt down. Do you (or your buddy) really want to take that gamble with his brass engines ? I sure wouldn't.
The better approach would be to just disconnect your DCC from the layout and connect a regular DC throttle to run them. It's just not worth chancing it.
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
Me thinks this is an accident looking to happen. Can you run the DC locos? Yes, it can be done. Is it good practice? No, not at all.
Just my opinion, nothing more.
ENJOY !
Mobilman44
Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central
Or, here's another slant....suppose you and your friend don't have a liking for sound-equipped locomotives. He likes his brass silent and reeeeeeaaaaaalllly good lookin'. You ask him to place his fine specimen on your DCC rails with your system willing to address "00" and you both smile expectantly. You acquire "00" on your throttle and begin to add speed steps. His super-detailed brass, formerly silent, will suddently begin to ziiiing and groan in protest at getting 60 hz pulses of rather itchy voltage pulsing in places that would make its eyes pop if it had any.
You'd both look at the loco askance, and then at each other, and you'd quickly reach for your throttle and shut off power to the rails. In all of that horrid experience, lasting perhaps ten seconds, the locomotive might have moved four whole inches down the rails, but sounding like one of those sparky rail grinders in the real world.
Yes, you can run DC locomotives on some DCC systems, but I have yet to read of a salutary experience from anyone. An unfortunate few have said they melted their plastic shell after leaving the loco parked too long while subjecting its drivetrain to the DCC pulses.
I actually did try it a couple of times myself using a cute and finely detailed, plastic shelled, Proto 2000 0-6-0 switcher before I had it converted to DCC. The second time was just for confirmation...it was a noisy bust.
Since you plan to use zero stretching, the decoder equipped locomotives will just ignore that since it isn't addressed to them.
If you were to remove the DCC sytem and connect an analog power source, there is a complication: if your DCC locomotives are not set to "DCC Only", they will switch to analog operation and accelerate as you open the throttle.
Another issue is the motors in the brass locomotives. Some motors, such as expensive coreless motors, will be destroyed by the digital waveform, and this happens quickly. Others may overheat. As well as groaning and complaining about the digital signal they are getting. So don't leave them on DCC any longer than needed.
Remove or isolate, words to live by, or at least, words to operate by.
Having regular decodered locos on that track while using zero stretching will have no effect on the decoders. If you instead disconnect the dcc system and hook up a dc power pack, they would all take off unless you set cv29 to disable dc operation.
Address 00 is safe for old heavy solid armature motors. The have the mass to dissipate excessive heat build up. A coreless motor will be quickly burned up.
Zero stretching was common in the early days of dcc with n scale until decoder a got smaller. There weren't mass loco fryings.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
There must have been enough motors damaged to warrant the manufacturers to do something about you not doing it. Apparently Atlas was getting tired of the rash of returned burnt motors, so installed a couple components on the 8-pin dummy plug that would prevent you from running the engine using 00. As soon as you place the engine on the track, it would create a soft short to your system. Easily by-passed by using a non-filtered dummy plug, but I'm sure your warrantee would be out the window.
All very good information.
A few years ago I used an infrared temperature scanner which is able to "see" through the motor case and the two points where the brushes contact the commutator get very hot when the loco is sitting still. The AC component in the DCC signal causes the armature to oscillate at the system frequency which you already know. The temperature does drop as the armature turns. Still an iffy issue.
Below is a link when this fellow used the Bachmann EZ Command which can operate a DC only loco.
http://members.shaw.ca/sask.rail/dcc/DCC-waveforms/DCC_waveforms.html
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
Now you see another reason to have one single power cutoff for your train room. All the manufacturers that support using address 00 also caution you against leaving a loco just sitting there on DCC track. Break for dinner, but leave the power on and...well, too late. Use it sensibly, is it NOT dangerous to use zero stretching.
The actual question from the OP was if he hsould take regualr decodered locos off the track to use zero stretching - that's not necessary, nothing will happen to a decoder when the command station issues stretched 0 packets. They will in fact respond normally to the DCC throttle except possibly with a slight lag - if only a few are running, you won't even notice it. If you previously had command lag with 100 locos running, with zero stretching there now may be lag at 50. There's nothing mysterious or arcane with zero stretching, in fact at higher speeds it pretty much is identical to what you'd get from an SCR throttle, although at a higher pulse frequency, which is better than th 60hz pulses you get from SCR throttles.
Funny thing about this topic (and I think I noted this before) but it's right downt he line - if your primary system is one that does not or never did support zero stretching, it's an evil, horrible thing nad will destroy locos. If your primary DCC system is one that does support it - it's ok, with the well known cautions, and most of us have tried it and did not fry locos.
I think it was Jeffrey ran a test some years ago where he deliberately cooked some locos just leaving them sit standing on DCC track to see how long they would hold up. In general, the cheaper older motors survived best.
Fear not the zero stretch - fear the wise guy who leaves the loco sitting on powered track and walks away for a break.
And as stated before - no coreless motors EVER. So if you have one of those new Kato F40PH's witht he truck mouted motors - never ever let that get a whiff of direct DCC. And never try to use a non-silent running decoder with a coreless motor, either. A non high frequency decoder hits the motor with a pulse that it little better than the straight DCC with no decoder. Coreless motors are easily damaged by those sorts of decoders as well. Anything with high freuency, "supersonic" or "silent running" is OK with all motor types - the Euro ones like CT, ESU, Lenz Gold, etc. even have a CV or three to adjust for the type of motor you connect - this is seperate from the BEMF adjustment.
rrinker Now you see another reason to have one single power cutoff for your train room. All the manufacturers that support using address 00 also caution you against leaving a loco just sitting there on DCC track. Break for dinner, but leave the power on and...well, too late. Use it sensibly, is it NOT dangerous to use zero stretching. The actual question from the OP was if he hsould take regualr decodered locos off the track to use zero stretching - that's not necessary, nothing will happen to a decoder when the command station issues stretched 0 packets.
The actual question from the OP was if he hsould take regualr decodered locos off the track to use zero stretching - that's not necessary, nothing will happen to a decoder when the command station issues stretched 0 packets.
I, for one, misread the OP's original question, or did I?
So, a visitor wants to run DC brass locos on the OP's DCC layout.
Are we saying that there is no need to remove or isolate the DCC locos?
Are we saying that the DC brass loco may be damaged, or will be damaged?
Not that the OP is asking this question, but can you run a DCC loco on a DC layout?
Should you ever run a DC loco on a DCC layout?
Should you ever disconnect your DCC system and run your layout on a DC power pack?
Should you ever disconnect your DC power pack and run your layout on DCC?
Or, should you just dedicate your layout to either DC or DCC and never run anything but DC locos on a DC layout and never run anything but DCC locos on a DCC layout?
richhotrainOr, should you just dedicate your layout to either DC or DCC and never run anything but DC locos on a DC layout and never run anything but DCC locos on a DCC layout?
This option gets my vote.
It seems like every time time I start enjoying the taste of the sausage someone has to drag me into the pork processing plant and show me how it's made.
Now I have to worry about coreless motors and "non-high frequency decoders".
Is there a list of which locomotives use coreless motors and which decoders are "non-high frequency"?
I have the right to remain silent. By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.
The short answer to the OP's question "Do I have to remove my DCC locos when running a dc loco on address "00", is no
floridaflyer The short answer to the OP's question "Do I have to remove my DCC locos when running a dc loco on address "00", is no
Actually, the OP's question was "Should I..." followed by:
GeromeIs removing my DCC locos a good precaution?
Which invites the subjective responses you seem to have an issue with.
richhotrain I, for one, misread the OP's original question, or did I? So, a visitor wants to run DC brass locos on the OP's DCC layout. Are we saying that there is no need to remove or isolate the DCC locos? Are we saying that the DC brass loco may be damaged, or will be damaged? Not that the OP is asking this question, but can you run a DCC loco on a DC layout? Should you ever run a DC loco on a DCC layout? Should you ever disconnect your DCC system and run your layout on a DC power pack? Should you ever disconnect your DC power pack and run your layout on DCC? Or, should you just dedicate your layout to either DC or DCC and never run anything but DC locos on a DC layout and never run anything but DCC locos on a DCC layout? Rich
He was talking about running the DC brass locos on address 00, also known as zero stretching because that's how it works - makes either the top half or bottom half of the DCC 0 bit longer than the opposite half, so a DCC decoder still sees this as a 0 bit in the command stream, but the effect is instead of a balanced waveform with equal parts above the common and equal parts below, which is a net 0 volts DC, you have more above or below, resulting in a net positive or negative DC and a DC motor will spin one direction or another.
Since the DCC signal is still fully present, a loco with a decoder will not move unless it gets commands to its address.
It is possible to cook DC motors if you leave them sitting on DCC track not moving. The mass of the armature and windings (ie, how well it can dissipate heat) determine how long this may be. WHen the motor is turning though, it allows airflow over the armature to keep it from overheating.
If you have CV 29 set to allow analog conversion, DCC locos will work fine on most DC power, just slightly slower due to the voltage drop in the decoder. Not as severe as dual mode sound locos - they deliberately keep power from the motor so you can get enough voltage to run the sound system so you get the tartup and idle sounds without the loco moving. Some DC power systems, such as those that use a pulse width modulation system, produce a DC signal that looks somewhat like DCC, and it can confuse the decoder. But it won't fry it. If you have CV29 set to not allow analog operation, the decoder will sit there on DC track and not move. It also will not fry the decoder.
I run DC locos on DCC all the time to test run them before putting a decoder in. Haven't fried one yet. Running a DC loco on DCC was the only way I was able to free up a very stiff Bowser PRR T-1 that had been built and packed away for 20+ years and never run. My DC power pack just tripped the overload trying to move it, but my Zephyr got it going, those rough pulses from DCC were just what it needed to get things turning. Not all systems support this.
If you want to run all DC locos - why not. However, things like autoreverses will not work, some circuit breakers may not be compatible with DC, and many DCC detection systems are also not compatible with DC. Most of the time, this means "won't work" not "will fry". This is the ONLY way to run DC on a DCC layout - DISCONNECT the DCC system. Connecting both at the same time WILL fry something.
ALso a why not. If the layout runs fine on DC, it likely will on DCC. There are some caveats on larger layouts wired for common rail but if you have one of those typical Atlas 4x8 or smaller plans, there's no reason it shouldn't work by swapping the DC power pack for a DCC system.
As adove - both is doable with some concerns, but NEVER EVER at the same time. One of the other - the BEST system is to have a plug on both the DCC system and the DC power pack, and a socket on the control panel, so that only one may be plugged in at a time. Slightly less 100% foolproof is a DPDT CENTER OFF toggle, with the DC connected to one side and the DCC to the other, the center goes to the layout. The center off prevents any make before break contact issues that would connect the DC to the DCC.
To be politically correct "should I remove........". He can do what he wants but the dcc locos will not be affected by using address "00". Most of the discussion on this thread revolves around running a DC loco on address 00, and the effect this will have on the dc loco. I have no problem running my few dc locos on address 00, I don't do it often and they do not run as well as on regular dc, and there is a buzzing sound. I park the dc locos on a siding and kill the power to that siding so the dc locos are not receiving power unless I want to run them. But the address 00 has no effect on the DCC locos.
YES!
Correct IF you are running DCC. If you hook up a DC power supply (in lieu of DCC) you need to turn off alternate power mode, or isolate the DCC locos.
If it sits for long periods of time without moving it is likely to overheat and do damage. Open frame motors are more sensitive to this as they have higher currents.
You can run a DCC loco on a DC layout IF it supports DC (Alternate power) mode AND it's set to on (usually CV29). In fact most manufactures now make their decoders support BOTH out of the box.
Not recommended, especially for high current motors, but possible.
Only if your DCC locos have alternate power mode turned OFF.
If your locos have DCC decoders, why not?
Don - Specializing in layout DC->DCC conversions
Modeling C&O transition era and steel industries There's Nothing Like Big Steam!
Reviewing the OP's post, he states that in the past they have run the brass dc locos on address 00 (apparently without incident) His question is is it a good precaution to remove all his dcc locos when doing so. From an electronic or electrical standpoint there is no reason to remove the dcc locos. If he feels better doing so then he should do it.
floridaflyer Reviewing the OP's post, he states that in the past they have run the brass dc locos on address 00 (apparently without incident) His question is is it a good precaution to remove all his dcc locos when doing so. From an electronic or electrical standpoint there is no reason to remove the dcc locos. If he feels better doing so then he should do it.
richhotrain floridaflyer Reviewing the OP's post, he states that in the past they have run the brass dc locos on address 00 (apparently without incident) His question is is it a good precaution to remove all his dcc locos when doing so. From an electronic or electrical standpoint there is no reason to remove the dcc locos. If he feels better doing so then he should do it. Is there any risk that the DCC command station or booster can be damaged? Rich
Is there any risk that the DCC command station or booster can be damaged?
Not running one DC loco. I have done that in the past with an old MRC 2000.
Is that a No?
Yes. Ruinning one DC only loco.
DCC systems have over current protection.
Right now, there is only the MRC 2000, Bachmann EZ Command and a Digitrax system that can do this. Not aware of what might be available across the Pond.
As I think about it, Lenz might have a system.
richg1998 Yes. Ruinning one DC only loco. Rich
You can run more than one but speed matching is not easy. Both DC locos will respond to the zero bit. No individual operation possible. The same as running two locos on a DC only layout. Don't try to confuse this issue more than you have to.
You will have DC locos running like a DC only layout with normal DCC locos.
The DC locos will be "sound" locos with the buzzing.
I use to have a Bachmann tender drive 4-4-0 with Lenz N scale decoder pulli a freight. A Roundhouse MDC DC only 0-8-0 was a pusher.
Agree richg, to throw a bit more into the mix, you can run a dc loco on address 00, while running a dcc on it's address. Don't know why one would do it but it is possible. I've tried it for a short period of time. Don't think there would be any long term effects but can't prove that.