Don't even think about it - the charger interlock on the Elcon outputs whatever the traction battery voltage is when not charging, and 0v when charging. It's pretty much useless, in other words, unless you just happen to have a contactor with a coil rated for your pack voltage.
A better way to implement a "universal" charger interlock feature is to use a relay with a 120VAC coil connected between line and neutral (so it will work on either 120V or 240V and then use the NC contacts to interrupt the 12V power to the controller (IGN on the Soliton1). That way, whenever the car is plugged into AC power the relay will be on so the NC contacts will be pulled open.
This isn't a foolproof setup - a purely mechanical switch that opens whenever a cord is plugged in, or even if the charging port door is open, is an even better method as it will prevent you from driving off even if there is not AC power present (e.g. - the breaker tripped).