Anthony Ashley Posted June 22, 2013 Share Posted June 22, 2013 I am building an N gauge layout 35 by 16 feet. It also has a lower level with 2 turn tables. It will have a large number of locos operating. To determine how many power districts with power boosters I require I need to understand the power requirements for each loco. The locos will be a mixture of sound and non sound. I therefore need to determine the power requirements for both sound fitted and non sound fitted locos while standing idle on the layout and while being operated. I have an NCE 5 amp power house pro controller. Once I have determined the power requirements for each section of the track I can divide it up into power districts. I have a thread showing the layout development and plans at the thread North Welsh Coast Railway - Welsh Dragon rail on page 2. Once I have sorted the power arrangement as with the number of boosters I shall consider how many circuit breakers and then track detection issues. This is my first layout so I m in need of assistance if any one can help. I am happy to email my plan to any one if they are able to assist. Regards, Anthony Ashley Link to post Share on other sites More sharing options...
Vonzack Posted July 2, 2013 Share Posted July 2, 2013 Hi Anthony, It would be great if there was an 'X locos at Y mA' type solution to your question, but in reality, each loco may draw different amounts of power from your system. The only guidance I can give is that generally I assume a loco sat on the layout will draw around 100 mA while idle, when moving it will draw up to 500 mA, but assume the maximum. If you use these figures for your calculation, you should be able to work out your Power Requirements and where your Power Districts need to be. Sound locos would be different, but I'm not sure what the typical mA overhead would be for a sound decoder, I would guess maybe 100-200 mA. Remember, if your boosters are capable of 5A, then you also want to leave some head room for your chosen Power Managers (these split your booster power into Power Districts) to detect a short, so work things out based on a max draw of 4A. The other advice I would give you is to block your track based on your assumed train lengths and don't include pointwork in the blocks. If you want to use automation to be able to stop a train in the block, further divide it so that you have a deceleration and stopping zone of around 30cm (this leaves you free to choose your automation software). I hope I've been of some help, but I guess I've raised allot more questions for you, but you have to start somewhere ;-) Cheers, Mark. Link to post Share on other sites More sharing options...
mjkerr Posted July 3, 2013 Share Posted July 3, 2013 My previous layout had 60 locos (motors) and I can handle up to 8 at any one timeThere is no need for additional power suppliesHowever, I would suggest installing breakers so that any derailments only shut down the affected zone and not the entire layout, maling them easier to identify Link to post Share on other sites More sharing options...
Anthony Ashley Posted July 4, 2013 Author Share Posted July 4, 2013 Mark and MJ, Thanks for the comments. I have reworked my power consumption figures and arrives at the following outcome. I have conducted further research and believe I can get away with 3 LEDs per coach drawing .01amp per LED for N gauge. The blog indicated that half the power results in a very slight dimunition in light, which will probably give me a more realistic light for the 1960s anyway. The above loco rakes then change to the following calculations: (full power) Loco with sound and 8 coaches with 3 LED per coach-49 amp (loco o.25+.24 for lights=.49 amp) (full power) Loco with sound and 10 coaches with 3 LED per coach-49 amp (loco o.25+.3 for lights=.55 amp) (full power)Loco with sound and 16 coaches with lights with 3 LEDs each- .48 amp (loco o.25+ .48 for lights=.73 amp) Operating goods loco with sound and brake tail and interior light - .27 amp What do you think? Please add you comments. Regards, Anthony Ashley Link to post Share on other sites More sharing options...
Edwin_m Posted July 4, 2013 Share Posted July 4, 2013 If you put the three LEDs in series they should still light at DCC voltages and will only use 10mA (0.01A) for all three. Link to post Share on other sites More sharing options...
Crosland Posted July 4, 2013 Share Posted July 4, 2013 If you put the three LEDs in series they should still light at DCC voltages and will only use 10mA (0.01A) for all three. And don't forget "diversity" [1]. You wil rarely have all locos operating at full power. Andrew [1] A term from household electrical instalation where, e.g., a cooker circuit can be rated less than the theoretical maximum required by the cooker if every element where running continuously at full power. Link to post Share on other sites More sharing options...
Anthony Ashley Posted July 5, 2013 Author Share Posted July 5, 2013 Edwin and Andrew, Thanks very much for your comments. At one stage I thought I was going to have a power usage of 2.25 amps for a 16 coach N gauge rake. This would clearly severely limit the number of rakes on the layout at any one time. If I am able to power the LEDs in series as suggested my power bill for a 16 rake train drops to .25 (loco with sound)+.016 (3 LEDs per coach with 16 coaches) Total for the rake=.41 I have determined that on average the rake length is 10 coaches. Power consumption is therefore .25+.01 =.35 For the 5 amp booster I can therefore run approx 14 locos per power district. This is probably sufficient power to run one power district on the up an done on the down line. However given the size of the layout and therefore the distance of the wire run, 1 power district per main line would require a length of wire 96 feet. I an using 2.5m2 cross section or 13 gauge wire. I understand the maximum advisable run for 13 gauge wire is about 50 feet, hence the need to divide the main up line into 2 power districts and similarly with the down line. Can anyone confirm if these calculations are accurate. Regards, Anthony Ashley Link to post Share on other sites More sharing options...
Anthony Ashley Posted July 5, 2013 Author Share Posted July 5, 2013 POWER CONSUMPTION These figures are based on .010 amp for an LED which if run in series still uses .010amps. All comments are welcome. Regards, Anthony Ashley Link to post Share on other sites More sharing options...
Crosland Posted July 5, 2013 Share Posted July 5, 2013 For the 5 amp booster I can therefore run approx 14 locos per power district. This is probably sufficient power to run one power district on the up an done on the down line. However given the size of the layout and therefore the distance of the wire run, 1 power district per main line would require a length of wire 96 feet. I an using 2.5m2 cross section or 13 gauge wire. I understand the maximum advisable run for 13 gauge wire is about 50 feet, hence the need to divide the main up line into 2 power districts and similarly with the down line. Your 96 feet of 13 gauge wire wil have a resistance of approx 0.2ohm and a voltage drop of 1V at 5Amps. Under normal conditions the voltage drop will be much less than this, as the load is distributed around the layout. If you wire as a ring <duck for cover> then the resistance and voltage drop wil be halved. Do, however, do the "coin test" and check that the booster(s) trip with a short circuit at the farthest point of the layout, and fit filters to such a large layout. Rather than split the layout into up/down or up/up/down/down as you propose, you could split it left/right so each half is only 48 feet and side stepping the discussion about rings. Andrew Link to post Share on other sites More sharing options...
Anthony Ashley Posted July 7, 2013 Author Share Posted July 7, 2013 POWER<br /><br /><br />Andrew,<br /><br />Thanks for your comments<br /><br />On second thoughts if I take the main power bus from the booster and send it left and right from the booster the length will be less than 50 feet other way, even for 1 power district. Will this produce a drop in power of .5 amps as you have indicated above.<br /><br />Regards,<br /><br />Anthony Ashley Link to post Share on other sites More sharing options...
Crosland Posted July 8, 2013 Share Posted July 8, 2013 POWER<br /><br /><br />Andrew,<br /><br />Thanks for your comments<br /><br />On second thoughts if I take the main power bus from the booster and send it left and right from the booster the length will be less than 50 feet other way, even for 1 power district. Will this produce a drop in power of .5 amps as you have indicated above.<br /><br />Regards,<br /><br />Anthony Ashley Don't forget the current has to go there and back, so your 50ft in each direction is stil 100ft round trip when calculating voltage drop. Andrew Link to post Share on other sites More sharing options...
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