Lincoln Speedtec 405SP Options FAQs
Straight answers to the questions people ask when choosing options such as coolers, feeders, cables and trolleys for a high-current MIG power source.
Do I need a water cooler and a water-cooled torch?
A water-cooled torch carries high current for long periods with less heat building up in the handle, so it suits heavy, continuous welding. Air-cooled torches are often rated lower for continuous use, and a torch's rating depends on the gas and the duty cycle, so always compare the torch's rating for your own gas and duty cycle.
If your work is mostly short runs below the torch's air-cooled rating, a water cooler may not be needed. If you do run a water-cooled torch, it must have a working cooler connected. Check the torch and power source data before you decide.
How does a water cooler protect the torch, and what should I check?
Coolers normally include a flow switch or sensor. If the flow drops, for example from a kinked hose, a blocked line or low level, it signals the power source to stop welding so the torch does not overheat.
Before striking an arc, run the coolant and check hoses and fittings for leaks while it is flowing. Look for cracks, bulging or soft spots. Leaking coolant near the torch is also an electric shock risk, so stop and fix leaks straight away. Keep the cooler's fins and fan clean and check the level every day.
What does an interconnecting cable carry, and how long can it be?
A cable between the power source and a separate wire feeder usually carries the welding current, a control signal and the shielding gas, and on water-cooled versions the coolant hoses as well. A loose welding connection can overheat, so tighten each connector fully as the handbook says.
Maximum length depends on the maker, the process and the cable size, because long runs cause voltage loss. Do not join cables together unless the handbook allows it. Use the length the maker specifies for your machine.
Why are there air-cooled and water-cooled versions of the same cable?
The water-cooled version includes coolant hoses so that the cooler can supply the torch through the feeder, while the air-cooled one does not. The two are not normally interchangeable, because the connections and the cable construction are different.
Choose the version that matches how your torch is cooled. Check that it also suits your power source and feeder, because connectors and control wiring differ between machines. The handbook for your power source lists the matching cable types.