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Are their several different topics that are being confused with each other here? I believe there two different "safety disconnects"...one for mechanical safety and one for electrical safety (including the HVIL)...
First, the high voltage safety disconnect. As stated by REMY, when disabled, there should be no high voltage outside of the battery box(es). To do this, we usually have DC contactors on both power cables going in/out of the battery box(es). These contactors are controlled by the VCU (or BMS) and should (usually) also incorporate a HVIL circuit which assures that unless all the HV connectors are mated fully and locked (closing the HVIL circuit), none of the contactors can close. In addition, you should use a manual (lockable) disconnect switch like the one above from WILCONRAD (and what I will use in both of our boxes) which will manually break the series circuit of the battery.
The second is a drive motor safety disconnect: this is a disconnect that physically breaks one of the battery connections to the traction motor inverter to prevent the mechanical motion of the traction drive. I.e., the vehicle doesn't accidently move on it's own.
For example, here is the disconnect plug for the Nissan Leaf:
It ALSO has the HVIL pins in it so removing the plug also breaks the HVIL which should also open all the battery contactors preventing the high voltage from leaving the battery boxes. So, this plug alone doesn't prevent high voltage from leaving the battery boxes, but does prevent high voltage from getting to the traction inverter and (with a functioning HVIL circuit) disables the high voltage battery contactors from closing.
First, the high voltage safety disconnect. As stated by REMY, when disabled, there should be no high voltage outside of the battery box(es). To do this, we usually have DC contactors on both power cables going in/out of the battery box(es). These contactors are controlled by the VCU (or BMS) and should (usually) also incorporate a HVIL circuit which assures that unless all the HV connectors are mated fully and locked (closing the HVIL circuit), none of the contactors can close. In addition, you should use a manual (lockable) disconnect switch like the one above from WILCONRAD (and what I will use in both of our boxes) which will manually break the series circuit of the battery.
The second is a drive motor safety disconnect: this is a disconnect that physically breaks one of the battery connections to the traction motor inverter to prevent the mechanical motion of the traction drive. I.e., the vehicle doesn't accidently move on it's own.
For example, here is the disconnect plug for the Nissan Leaf:
It ALSO has the HVIL pins in it so removing the plug also breaks the HVIL which should also open all the battery contactors preventing the high voltage from leaving the battery boxes. So, this plug alone doesn't prevent high voltage from leaving the battery boxes, but does prevent high voltage from getting to the traction inverter and (with a functioning HVIL circuit) disables the high voltage battery contactors from closing.
