I have just bought a Clarke 155 en without an instruction manual. I would be most grateful for some help in setting this up. I notice that the earth clamp is plugged into the positive on the front and the negative lead goes into the machine near too the cable feed. Is this right? I am a complete welding novice but have grand ideas that I may be able to weld the chassis of a Land Rover that I have just bought for my son. Any help greatly appreciated.: