What you have there is a BGlobal smart meter, ignore the Npower label.
The meters are programmed by modem and can have any tariff sent down to them, so you wont have any clocks or teleswitches attached to it. There may be a contactor (single or poly) wired in to switch the load on to any heating circuits if you have an eco7 type setup, though if you have two rates they'll probably be an evening/weekend tariff.
The meters have loads of info on them, including the tariff. Press the lower button to cycle through the screen, you will need to be on 'set A' (it appears in the screen) if it's on 'set B' press and hold the lower button until the symbology on the meter goes to set A. Once you've done that you'll get the time, date, reads and a load more info on the screen at each press.
You'll eventually get to a screen which scrolls the 13-digit MPAN core, that or the meter ser number, to the left on this screen you'll see in smaller letters SSC...followed by 4 numbers, this is the tariff set on the meter. Evening/weekend normally has an SSC of 0920 or thereabouts, though it can vary a bit.
DO NOT remove the cover or play about with the meter, they have microswitches on the covers and will record any power cuts and possible tampering on the inbuilt alarms....ring EOn and ask them if they support BGlobal meters, if they do ask them to check the alarms and the tariff is correctly set, NPower may have inadvertantly done something to the meter....highly unlikley but you never know.
There is a possibility that E-ON dont use the smart meter reading systems, not every supplier does; that said it should still be set to the timings set by BGlobal when the meter was originally fitted.
It should be easy enough to see if a phase has been dropped, press the button untill you get set B displayed, then scroll through the display, you should get the current, voltage, power factor and a load more info on each phase (the phases are marked L1/L2/L3) If theres a dropped phase the readings for that phase will be zero.
