I assembled the cut-50f unit. I plugged the unit into a standard 20amp 110v outlet and attached my air hose. I then attached the ground to the metal I was going to cut. I turned the power on and it immediately made a popping sound from in side the case, then blows breaker. Then a burnt smell came from the unit.I sent in a request on what to do. I will change my rating once my unit is fixed.Nov. 7 2019 Updated response from seller:They wanted me to recreate on video their machine causing a electrical short and smoking. "Please put your life and your property in danger on video so we can send it to the manufacture." This what they asked me to do.I am so far very concerned with how they are handling a defective product that they sold.This was my response:"I will not try to recreate what happened with videos, it may catch on fire or cause injury.Plesse send a replacement unit and a postage paid return shipping label for the defective unit.If you can not send a working unit, email me a postage paid return shipping label and I will return unit for a full refund.It surprises me that you would require your customers to take such dangerous actions that could possible could cause a fire, bodly injury or death.Thanks for your quick response to this matter."I will update once I hear back.Nov 9th, 2019 Update:They are sending me a new Cut-50F plasma cutter. I will update my review and star rating once I have had a chance to use the new unit.Nov 14th update:After a little back and forth with the seller, they did send me a new unit and it so far has worked as expected.