What is required to be done by a Comeng assisting train before coupling?

In a Comeng train, prior to coupling, it is essential to turn the Red Emergency Control (EC) switch to ensure that the train is in a safe state and that the emergency functions are properly managed. This step helps to prevent any unintended activation of systems that could lead to hazardous conditions during the coupling process. The Red EC switch is specifically designed to handle emergency situations and put the train in a controlled state.

Setting the trip and power, isolating the coupler electrically, and resetting the emergency circuit are important procedures in maintenance and operational protocols, but they do not specifically address the immediate safety concerns associated with coupling. The primary focus before coupling is ensuring that the systems are ready and safe to engage with another train, which is why turning the Red EC is emphasized in this scenario.