So I'm making a manual precharge circuit for a solar car's motor controllers, and need to use a 12 V source to switch a contactor on/off thus switching between a resistive path and a short circuit from battery to the motor controllers. I was planning on using a 12V lead-acid battery as my source, however, the contactor (besides inductance) has a low (real) resistance (0.417 Ohm), so I'm worried that I would short the battery by putting the contactor input/control terminals across it. Would this be the case? Here is the link to the contactor spec sheet: https://www.te.com/commerce/DocumentDelivery/DDEController?Action=srchrtrv&DocNm=EV200_R_TBD_KILOVAC_EV200_Ser_Contactors&DocType=CS&DocLang=English
1 Answer
That resistance you quote is for the auxiliary contacts, not the coil. The coil takes a peak current of 3.8A (ie a 4 ohm load) and features a built in economizer which limits the current draw after closing to 130mA (ie a 92 ohm load).
You need to be looking at the coil operating part of the data sheet: