Aircraft struck a ground power cart with the right prop when the trainee Marshaller guided the DHC-8 into the gate on the CRJ line.

Narrative

When we arrived at the gate there were no rampers there to marshal us into the gate so we waited outside of the gate until the wing walkers arrived. The Marshaller showed up and held us outside of the gate until the wing walkers arrived; we continued to wait. When all the rampers were in place; the Marhsaller raised his wands and started to guide us in to the gate. I taxied slowly in to the gate as directed by the Marshaller. After the power cart; which is located on the right side of the plane when we park; disappeared from my vision; I asked my First Officer how the power cart looked on his side. He said it was clear. The Marshaller was starting to raise his arms to cross them when the #2 propeller struck the power cart. We secured the engines and the plane as soon as possible. We evacuated the passengers. There were no injuries to the passengers or the crew. The Marshaller was guiding us on the CRJ-200 mark for the gate not the DHC-8 mark. Both marks are on the same line but the CRJ-200 mark is deeper in the gate than the DHC-8 mark. The Marshaller that was guiding us in to the gate was a trainee. The training program for rampers should be changed so that a trainer is right by the trainee to give them guidance immediately should they make a mistake.