Measuring power uptake of heated bed?

[JohnInOttawa 104]

While the UM3X' project printer' is now passing all diagnostics and active levelling, I notice a significant difference in time to target heat for its bed vs my UM3 (non extended).  My initial inspection doesn't show up any connection problems or signs of arcing, but I would like to be able to observe as much as I can.  I'll have an imager on the unit for the next test, but as I also have a watt meter that I can put inline between the power supply and the mains outlet, I wondered if it would make sense to compare each of my printers' wattage during a heating cycle.

 

Would it make sense to expect both the Ultimaker 3 and 3X to use the same power to heat?  The only difference I can think of would be the length of the cable from the board to the bed and I can't imagine that radically altering consumption.

 

Maybe related, I have noticed that active levelling executes differently on the UM3 and 3X, with the 3X doing a protracted heating cycle first, then levelling quickly, while the UM3 does not seem to do much of a heating cycle at all.  I have yet to synchronize the firmware, so that may be a factor.

 

Any other suggestions welcome!

Thanks!

John