Inspired by Alonso's booster question (the "a question" topic), I made some measurements of the power consumption of my locos when controlled digitally. I have previously made measurements in analog AC operation. Some general results:
<ul><li>Delta locos draw most power. 6090x come second, C-Sine are lower and the "Glockenancker"-motors have the lowest consumption. </li>
<li>Märklin's own figures on power consumption are exaggerated. I have measured 12-15 VA on an accelerating 37761 railcar (60901 motor) going uphills with internal lights on, in AC operation. In digital operation with the same model there is no way to get near that figure.</li>
<li>In digital operation, the power consumption is speed dependent but not very load dependent. This is similar to what you see with analog and Delta locos in AC mode. In AC mode, the power consumption of the fully regulated motors seem more load dependent than speed dependent. </li></ul>

The highest power consumption I measured in digital mode on any model was 8.6 VA. This was a 39700 Railcar (C-Sine), going full speed up a 5% grade with head lights and inner lights on. This is a C-Sine model, but it has many inner lights, that's why it was the worst. With lights off, it drew only 3.6 VA under the same conditions.

My only Delta loco, a 3132 (DHG 700 diesel) drew 8.2 VA alone and 8.4 VA with four cars, in the same 5% grade.

A 37744 (BR216 diesel, 60901 motor) consumed 4.9 VA with lights on. With four cars it rose to 5.0 VA and with 20 cars to 5.5 VA.

A 37646 (MaK diesel, "Glockenancker"-motor with Märklin regulated decoder) drew 3.1 VA with lights on. With four cars 3.9 VA and with 20 cars 4.4 VA. Of this, the lights contribute with about 0.8 VA. On flat ground with lights off and four cars, it only consumed 1.9 VA.

A 37645 with LokPilot decoder (same as the 37646 except for the decoder) generally drew 0.25 VA less than the all Märklin version. The difference was the same independent on load conditions.

Two older locos, a 3067 NOHAB diesel and a V60 diesel, converted with 60904 and 60903 respectively consumed around 5.5 VA alone and 5.9 VA with four cars, i.e. around 12-18 % more than the 60901 loco.

Note that the figures are at full speed and 5% grade uphills. On flat ground and/or lower speed the consumption is lower. The motor plus head lights on a fully digital loco should hardly exceed 4 VA when running in normal speed on flat ground. Inner lights, smoke generators and TELEX will add a lot of power consumption of course.

Power consumption is not very speed dependent either for 60901 locos. At speed step 1, it is around 75% of the full speed consumption and at speed step 6 it is 80-90% of the full speed consumption. The consumption of the C-Sine and "Glockenancker"-motors is more speed dependent, 70-75% of full speed consumption at speed step 6, and down to around half at speed step 1. This is for the motor alone. When you take head lights and inner lights (not to mention smoke generators and telex) into account, the savings by "careful driving" will be even less.

No, I have converted all my locos except a 3104 and an old SBB crocodile, and those two are not in good shape. I made some tests long ago that indicated around 7-8 VA for all three types. This was with head lights but with no other features. It was not very load dependent. The current was almost independent of speed, which means that the VA rating was almost proportional to the voltage. I never tested with cars at that time, but I had a 5% grade in the test loop.

In theory, if you had no lights on, no other devices (eg turnouts)and good track/contacts then you could run 13 c-sines... Neat!

You can only run 5.5 deltas... Big difference and possibly justifies the extra cost of c-sine engines..

I don't know anyone who could afford 13 c-sines (about A$8,000), but I wish I was one of them..

Sigh!

Dear Stuart, sorry I could not see your name on the reply screen.

Costas

Uffff!! To much complicated method for me. Any case a great job and a big help to calculate how many of our apreciated "bugs" can we run on our tracks. Thanks Perz.