Post by: mecmt on November 11, 2018, 02:49:46 PM
Post by: Alan on November 11, 2018, 03:29:56 PM
Post by: mecmt on November 11, 2018, 04:04:00 PM
Post by: mecmt on November 11, 2018, 04:23:37 PM
Post by: Alan on November 11, 2018, 05:08:28 PM
In the mean time you can use a switch and a resistor to make your own manual soft start. Turn the switch off, turn on the PWR56, wait 1 second, turn the switch on. When the switch is off (open) current will flow from the PWR56 through the resistor to the track. The resistor limits the amount of current that flows to a level below the PWR56 short circuit protection trip point. Once all the keep-alive circuits in the rolling stock finish charging the current demand drops to a level the PWR56 can handle. When the lights come on in the rolling stock the keep-alives have finished charging. Turning the switch on (closed) bypasses the resistor allowing normal operation. You will need to remember to turn the switch off before powering up the PWR56 each time.
Use virtually any single pole single throw (SPST) toggle switch rated at least 5 amps (will be marked on side). Use a 5 ohm 100 watt resistor.
Resistor: https://www.ebay.com/itm/50W-100W-0-01-50-Ohm-Shell-Power-Aluminum-Housed-Case-Wirewound-Resistor-New/162961019268?hash=item25f13bd184:m:mY-wkIfgcVQ8wv-unNLSrmg:rk:4:pf:0 (https://www.ebay.com/itm/50W-100W-0-01-50-Ohm-Shell-Power-Aluminum-Housed-Case-Wirewound-Resistor-New/162961019268?hash=item25f13bd184:m:mY-wkIfgcVQ8wv-unNLSrmg:rk:4:pf:0)
Post by: mecmt on November 11, 2018, 05:24:39 PM
Post by: Alan on November 11, 2018, 06:05:17 PM
Here is a pic I found on the web. It is typical of the connectors found on almost all made in China power supplies.
Do not do any wiring with a cord plugged into a wall socket!!!
The 'L' stands for line and is where you connect the black wire of an AC power cord. The black wire is the narrow blade on the plug.
The 'N' stands for neutral and is where you connect the white wire of an AC power cord. The white wire is the wide blade on the plug.
The ground symbol is where you connect the green wire of an AC power cord. The green wire is the round 3rd pin on the plug.
Each of the above are high voltage house current. Cover the connections so they can never be accidentally touched or shorted together. The shock will knock your butt across the room. Use a 3 prong AC plug. Do not use a 2 prong AC plug.
The 'COM' stands for common. It is often referred to as DC ground or zero DC volts (not to be confused with the ground symbol on the 115V input). COM is the same as the black wire of a PWR56.
The +V terminals are the 15 volt positive output. +V is the same as the red wire of a PWR56.
The two COMs are tied together inside the enclosure. +V1 and +V2 are tied together inside the enclosure. It doesn't matter which you pick. They are the same. Two connections for output are provided for convenience since these power supplies are often used to power more than one device.
Post by: Alan on November 11, 2018, 06:14:55 PM
Take all rolling stock off the rails. Turn on the PWR56. Add rolling stock to the rails one at a time until all cars and locos are on the rails. Run trains. Everything work okay?
Post by: mecmt on November 11, 2018, 08:01:56 PM
Post by: TwinStar on November 11, 2018, 09:19:33 PM
Post by: Alan on November 11, 2018, 09:26:42 PM
Although I was wondering and still am if the PWR-56 could supply the power for O scale 2 rail.
Yeah, the PWR56 is more well suited to HO. The larger scales tend to be more power hungry. I am guessing your lighted cars use incandescent light bulbs too. That really runs up the current demand. Other than the radio repeater function and, to a much lesser degree, the temp reporting to an HC the PWR56 is not stellar. Much more power for much less money is readily available.
Post by: Alan on November 11, 2018, 09:37:16 PM
Alan, I have some of these not installed yet. What would you recommend to use to cover the L/N/Ground?
Anything that has sufficient dielectric strength. Kapton tape? Good quality electrical tape? A piece of plexiglass affixed over the whole terminal end of the enclosure?
Post by: TwinStar on November 12, 2018, 06:53:58 AM
Alan, I have some of these not installed yet. What would you recommend to use to cover the L/N/Ground?
Anything that has sufficient dielectric strength. Kapton tape? Good quality electrical tape? A piece of plexiglass affixed over the whole terminal end of the enclosure?
I was hoping it was that simple. Thanks!
Post by: G8B4Life on November 12, 2018, 07:43:43 AM
A piece of plexiglass affixed over the whole terminal end of the enclosure?
This is similar to what I did. I used one of these sorts SMPS to create a charging station at work (it works great, one SMPS with 16 charging leads instead of 16 individual plug packs!). The SMPS I bought (MeanWell) had a little plastic clip-cover for the terminals but being a workplace this was not enough so I found an old electrical enclosure and cut it up make a complete shroud for the terminal end of the SMPS. The same thing could be done with a plastic electronics project box. I'll get a photo when I'm at work tomorrow, I forgot to get one today.
I mention this as while tape or no cover at all might be fine for home, knowing Jacob is into Free-mo then if he's at a meet then I'd caution that the meet might becomes a workplace under some sort of law and the terminals would need to be covered properly.
Back to the OP and the PWR-56, I tend to agree the PWR-56 is not really designed for O scale. Infact the documentation for the LM-3S-G doesn't even mention it, only "Ring approved power supply" or battery power.
- Tim
Post by: Alan on November 12, 2018, 08:28:51 AM
I mention this as while tape or no cover at all might be fine for home, knowing Jacob is into Free-mo then if he's at a meet then I'd caution that the meet might becomes a workplace under some sort of law and the terminals would need to be covered properly.
Very good point. Out in the public is very different than at home in your basement. Safety first!
Additional things to consider when enclosing a SMPS.
- Mount horizontal and provide ventilation. The holes in the factory enclosure are there for a reason. Until you get up into the higher output models, these units use convection cooling i.e. no fans. It is important for the convection air currents to work properly that the unit be mounted horizontally. If you build another enclosure make sure it has plenty of air holes arranged similar to the holes in the original enclosure. Power rating is reduced 50% if you mount a SMPS vertically or on its side. Not a good idea.
- SMPS generate radio frequency (RF) interference. That is why you always see them in metal enclosures or conductive plastic bricks (PWR56 and laptop supplies). This is why it is mandatory to use a grounded AC line cord. The case is connected to the 115V input ground screw connection. A grounded case suppresses RF emission. If you build another enclosure for the power supply make it out of metal as well. Ground it to the original enclosure. Double layer RF shielding will guarantee your SMPS isn't messing with other radio devices at the show.
- Hole diameter matters. Notice the case has a lot of little holes. Use the same size holes for your second outer enclosure. Do not drill big holes and do not cut open spaces. The relationship between the hole diameter and the RF wavelength is specific.
Factoid: The metal case of a SMPS is not 100% effective at blocking RF emission. For loco break-in I have a small SMPS powering a loop of track. Initially, the SMPS sat on the table next to the loop. I discovered that if I held the HC such that the SMPS was in the line-of-sight between the HC and the loco I would immediately lose connection to and control of the loco. The connection would not re-establish when the loco moved around the loop to where the SMPS was not in line-of-sight. The only way to regain control was power down and re-start. Moving the SMPS well below the table so it is never close to line-of-sight solved the problem.
Post by: TwinStar on November 12, 2018, 11:26:19 AM
A piece of plexiglass affixed over the whole terminal end of the enclosure?
I mention this as while tape or no cover at all might be fine for home, knowing Jacob is into Free-mo then if he's at a meet then I'd caution that the meet might becomes a workplace under some sort of law and the terminals would need to be covered properly.
- Tim
I build 'booster boxes' out of plastic Home Depot/Ace/etc style 16-19" tool boxes. They have a floor of 1/2" Baltic Birch with a Mean Well power supply and a Digitrax DB150 mounted inside. I have two sets of Anderson Power Pole plugs with DC on one side and DCC on the other so that I can power DC at home and be Digitrax compliant at a Free-mo setup. I have a a 92X25MM AC axial fan and vents built into the box to provide cooling.
These are used with the lid latched closed (ventilation described above) so I would imagine a simpler cover would suffice. I can attach an exterior label requiring AC power to be removed before opening as well.
Post by: G8B4Life on November 13, 2018, 06:50:43 AM
My SMPS, and the one I used for the charging station at work don't have holes but slots, just like your MeanWell for the accessory bus (mine is the same style as yours but different model NES instead of SE, they were a good deal at the time). I wonder if I should read the specs for any derating, the one at work I mounted upside down under a shelf; it's still horizontal just upside down.
It sounds like you've got everything covered Jacob. Being inside the portable power distributor "toolbox" you probably do only need something simple to prevent something accidentally bridging the mains terminals. I'm surprised that the supplies didn't come with a clear plastic clip-strip for that purpose.
- Tim
Post by: TwinStar on November 13, 2018, 08:41:54 AM
It sounds like you've got everything covered Jacob. Being inside the portable power distributor "toolbox" you probably do only need something simple to prevent something accidentally bridging the mains terminals. I'm surprised that the supplies didn't come with a clear plastic clip-strip for that purpose.
- Tim
I was surprised too but I imagine the target market for these is someone with enough electrical experience to know how to build a proper cover.
Post by: TwinStar on November 13, 2018, 08:43:30 AM
Mount horizontal and provide ventilation.
IIRC the PWR-56 requires a horizontal mount as well. I have to assume this is significant.
Post by: mecmt on November 13, 2018, 05:48:58 PM
Post by: Alan on November 13, 2018, 07:28:45 PM
Here is the dilemma. With a power supply too small you will have the same problem you have now. With a power supply too large you run the risk of melting things or even starting a fire if there is a short circuit like from a derailed locomotive. Additionally, your track length, joiner integrity, frequency and length of feeder wires, bus wire length and gauge, and future expansion plans factor into the answer.
You perhaps have read a lot of forum discussions about wire size for bus and feeders. Too often the advice given is based on how much current is needed to operate trains. Better advice is based on the buss and feeders' ability to pass 100% of available power supply current with minimal voltage drop. This approach assures the power supply over-current protection will operate as designed in the event of a short circuit. So, the question that should be asked is how large of a power supply will my wiring arrangement safely permit, not how much power do my trains need. Hence why I ask if you have a multimeter. With a few measurements on your layout we can give you a good and safe answer before you buy a power supply.