• Electrodes are hot or discolored to a straw color
• Arms and adapters are hot
• Tooling is hot
• Machine frame or components are hot

If the electrodes are hot then you aren't getting enough water flow. It takes at least 2 liters per minute for proper cooling for BOTH the upper and the lower if you are at max duty cycle. Get some visible water flow indicators for each of the following parallel lines: Upper Cu, Lower Cu, TX and SCR. EACH line should have 2 liters per minute so the machine should have at least 8 liters per minute total. MFDC machines may need even more.

Arms, adapters, tooling, platens and other areas need some water if they are thinner than RWMA Bulliten 16 standards. Include these in the upper CU and lower CU water flow path. If they are air cooled then they probably are not sized correctly for the application.If there is water and/or correct size then the Cu joint near the hot spot is probably corroded and/or dirty. Take the Cu a part and properly clean.(Note: Do NOT use chemicals to clean the Cu. Use gray scotch brite pads and elbow grease.) Properly apply some SS-30 lightly to the joints and re-assemble. Make sure the connections are as tight as practical. Do not over tighten and strip the threads!

Hot spots in the tooling or the machine can come from one of two things. Either the CURRENT is running through them and heating them up, or they are made of magnetic or plain steel. Tooling components should be made from Stainless Steel, Aluminum, or strong plastic materials. The root cause is the electro-magnetic field which is from the high CURRENT AC of the welding process. It can be avoided with the use of MFDC. If there are hot spots in these non-magnetic materials then it must be from a CURRENT leak path. This would also be cause for extra high amperage needed to make the welds.