Siemens 3RT1036-1AP04 contactor output voltage drops to 100-120V from 220V input

HI   I have 220V ac siemens Power contactor.  The contactors seems working correctly. However if gives very less voltage at the output of the contacts. For example if voltage at the inputs are 220V (AC), when the contacts are closed, the voltage at the ouput is 120 or 100V. Can somebody help me what is the problem and how to fix it. The contactor number is 3RT1036-1AP04 (Siemens)
 

Hi Noman-I wonder if one of the contacts is not closing. With the coil energized try measuring the voltage between the top contact and the bottom contact of each pole.  The voltage should be under a volt. If you find one of the poles with significant voltage drop across it, that's the culprit.I see that's a 3-pole contactor.  Are all three poles being used?  If not, move the wires from the pole with excessive voltage drop over to the unused pole.-Rick     

Hi Norman.... I wouldn't normally comment on a post like this - bit out of my normal area - except that I recently recovered some contactors off an old lift switchboard that exhibited very high resistance on some contacts.  Out of curiosity I took them apart and found the contacts caked with black sooty gunk.  I cleaned them with a wire brush and (when they were very pitted) fine emery paper, and they were very much improved.  However I wouldn't recommend this as a paying proposition - it was very fiddly and for the price of contactors, I'd go buy a new one in a commercial situation.  I am curious - (a) is this a contactor that has seen a fair bit of use?  (b) were you seeing those voltages on or off load (what sort of load?) and (c) do you have a new contactor to compare with?As Rick says, especially if one pole is better than the others then you've probably got the same problem - accumulated gunk from years of sparky operation...Cheers / David