Over the past few days, I've been tidying up the layout's wiring and creating a neater "desk" for my LGB MTS power supply, with the option to include an MTS booster. Before plunging in, it occurred to me that it would be a good idea to find out just how many amps I'm typically using. I also thought the results might be handy for others.
If you don't want to read the details, here are the key points for me from the tests:
1) Base load for DCC (i.e. before any trains are moving) may be significant if you have several ancillary modules attached.
2) Running unrealistically quickly or on steep gradients (like my 1 in 20/ 5%) uses a lot of amps. Running slowly looks better and may save you the cost of a big transformer or booster!
3) Unless you are running more than 6 LGB motors simultaneously, chances are you don't need a booster. If your other demands (lights, point modules etc) and your trains' speeds are low, 8 motors may just be possible, though it's pushing things.
To test, I attached my trusty multimeter between 50110 transformer and 55006p central station, thereby getting a measure of AC demanded of the transformer, not the DCC signal.
Here are the results (all shown in amps), measured today until rain stopped play:
Track disconnected, 55006p attached - 0.175
Track connected - 0.4
The 400 milliamp figure is my layout's "baseline", showing the inherent current consumption of the MTS central station (175 millliamps), plus two Massoth reversing loop units and 3 Massoth point/ switch modules (225 milliamps over 5 units).
Now to [STRIKE]play with[/STRIKE] test some locos....
LGB Mallet (2 motors)
stationary, lights off - 0.45 (DCC chip consuming 50 milliamps at idle?)
stationary, lights on - 0.54 (3 lights each taking 30 milliamps)
moving, MTS setting 6 (of 14), lights on - 0.6-0.9 amps (varying with gradients)
moving, MTS setting 12 of 14, lights on - 0.9-1.5 amps
2 * LGB 2095 diesels (4 motors)
stationary, lights off - 0.46 (2 DCC chips consuming 60 milliamps total at idle?)
stationary, lights on - 0.56 (3 lights each taking 33 milliamps)
moving, MTS setting 6 (of 14), lights on - 1.45-1.98 amps (varying with gradients)
moving, MTS setting 12 of 14, lights on - 2.6-3.7 amps
I also did some tests with the Mallet hauling seven LGB 2-axle hoppers, but the current draw was not significantly different. I suspect that tying 6 heavy coaches on the 2095s would increase the current draw, but need a drier day to test that theory!
Finally, switching points via a DCC module causes a severe, albeit momentary load on the transformer. Switching one point took typically 900 milliamps: switching two at the same time about 1400. Whether this momentary load would casue the transformer to trip out due to overload I haven't been able to test - yet!
If you don't want to read the details, here are the key points for me from the tests:
1) Base load for DCC (i.e. before any trains are moving) may be significant if you have several ancillary modules attached.
2) Running unrealistically quickly or on steep gradients (like my 1 in 20/ 5%) uses a lot of amps. Running slowly looks better and may save you the cost of a big transformer or booster!
3) Unless you are running more than 6 LGB motors simultaneously, chances are you don't need a booster. If your other demands (lights, point modules etc) and your trains' speeds are low, 8 motors may just be possible, though it's pushing things.
To test, I attached my trusty multimeter between 50110 transformer and 55006p central station, thereby getting a measure of AC demanded of the transformer, not the DCC signal.
Here are the results (all shown in amps), measured today until rain stopped play:
Track disconnected, 55006p attached - 0.175
Track connected - 0.4
The 400 milliamp figure is my layout's "baseline", showing the inherent current consumption of the MTS central station (175 millliamps), plus two Massoth reversing loop units and 3 Massoth point/ switch modules (225 milliamps over 5 units).
Now to [STRIKE]play with[/STRIKE] test some locos....
LGB Mallet (2 motors)
stationary, lights off - 0.45 (DCC chip consuming 50 milliamps at idle?)
stationary, lights on - 0.54 (3 lights each taking 30 milliamps)
moving, MTS setting 6 (of 14), lights on - 0.6-0.9 amps (varying with gradients)
moving, MTS setting 12 of 14, lights on - 0.9-1.5 amps
2 * LGB 2095 diesels (4 motors)
stationary, lights off - 0.46 (2 DCC chips consuming 60 milliamps total at idle?)
stationary, lights on - 0.56 (3 lights each taking 33 milliamps)
moving, MTS setting 6 (of 14), lights on - 1.45-1.98 amps (varying with gradients)
moving, MTS setting 12 of 14, lights on - 2.6-3.7 amps
I also did some tests with the Mallet hauling seven LGB 2-axle hoppers, but the current draw was not significantly different. I suspect that tying 6 heavy coaches on the 2095s would increase the current draw, but need a drier day to test that theory!
Finally, switching points via a DCC module causes a severe, albeit momentary load on the transformer. Switching one point took typically 900 milliamps: switching two at the same time about 1400. Whether this momentary load would casue the transformer to trip out due to overload I haven't been able to test - yet!
