1) Identify product on following page:http://www.hugo-mueller.de/elapsed-time-counters/mueller-bw-30-bg-30,p,en,8,34.html
2) Sales sheet shows model numbers and voltages and shows that product is hour meter:
BW30 is AC alternating current with choices 230Vac 115Vac or 24Vac
BG30 is DC direct current 12-48VDChttp://www.hugo-mueller.de/download/34_DB_BW30_BG30_BW22_GB.pdf
3) Hour meters normally have 2 terminals, but there is not a photograph of back of product.
Hoping you will photograph your product and post image on your website and add a comment to this thread with web address of image, along with other information you have.
4) Usual set up for timers and counters: terminal 1 is for black wire L or L1, and terminal 2 is for white wire N or L2.
If terminals are not labeled, then wires can be connected either way, but as you face terminals, terminal 1 is on left.
Hour meters are wired in parallel, not series.
For example hour meter on 240V pump: 2 wires go to pump.
Simply connect each hour meter terminal to one of the wires.
Another way to illustrate: If you test electricity using two-prong tester, you touch each tester lead to one of the wires. Hour meter connects same way.
6) How hour meters work:
Hour meters count number of hours electricity is turned on.
For example I have 240V Grasslin hour meter connected to water well pump.
Water well has pressure switch that turns pump on-off.
If hour meter is connected before pressure switch, then meter simply runs continually since it receives power all the time.
So hour meter has to be connected after the pressure switch. And then meter counts only when power is turned on to well pump. This way I see how many hours my pump runs and then estimate pump cost by multiplying hours x pump wattage.
Add a comment for more free help.
Also take advantage of fixya phone service.
For a price, expert speaks with you over phone while you work on timer or any do-it-yourself project.
Fixya is always less expensive than a service call.