I asked a question on the Tesla Forum regards to the contator and the what the rated voltage is and got this good explanation:
"You sound like you're confusing coil rating and contactor interrupter rating.
The coil voltage is the voltage passed through the electromagnetic coil, which has a dc resistance. Passing current through the coil will engage the contactor. Depending on the contactor application, 12V to 24V is pretty typical. The main reason is that most vehicles have a 12V or 24V bus - like Model S - so it's convenient to use that vs generating a specific voltage. A 48V coil is odd. Most coils however are perfectly capable of operating over 25~50% of rated voltage, as they can dissipate the extra power safely. For example most 12V relays will have an absolute do-not-exceed voltage of around 15 to 20V.
Going by the fact that they appear to be using a 48V coil, the Zero bike might not use a conventional 12V system and instead run everything (lights, computers, fans, etc.) off the unregulated DC bus, which is rather odd...
The other rating is the interrupting voltage. This is the highest voltage the contactor can safely interrupt and still meet lifespan expectations. The interrupting voltage should be higher than the pack voltage.
You also have to account for interrupting power, the maximum power the contactor can interrupt. (Power = Voltage x Current.) There are usually "several-time" ratings (for example, inverter failure, software must abort, high current flowing) as well as a typical rating; the average battery bus contactor will interrupt current when it is close to zero, because the inverter will have been shut down by then and the only current flowing is leakage/parasitics/quiescent draw from standby stuff.
Pitting on the contacts suggests the 2nd is not happening reliably so you are wearing out the contactor quickly."
So I looked at the contactor spec on the side of the one I pulled out of the Zero more closely, the contactor does say:
Coil: 48V DC
Contact: 48V DC 200A
So this implies that the coil which activates the contactor is indeed 48V which I would have thought as well to have been 12V.
Also the contactor interrupting voltage does appear to be 48V which is under the battery/pack voltage of 58V.