 Welding-site conditions and welding-wire diameter govern efficiency and size of power supply required for a job. Select a 100-A unit that runs from single-phase 115-V input for low-duty-cycle welding of aircompressortansasme sheet to l/s in. thick, feeding wire to 0.030-in. diameter. Medium-duty power supplies, 150-200 A, normally take single-phase 220-V input to weld steel to 3/16, in. and 0.035-in. wire at low-duty cycles. For high-duty cycles, as in mechanized welding, select a 250-A code machine, single or three-phase input at various voltages-these weld aircompressortansasme material to 1/2 in. thick with wire as large as 0.045-in. diameter. Taking three-phase input only and wire up to 1/6-in. diameter, 400-A units serve code for mechanized aircompressortansasme continuous-welding applications. For pulsed GMAW, shops use inverter and transistor power sources, constant-current or constant-voltage, that offer independent setting of pulse parameters. They employ synergic controls preprogrammed for a range of wire-feed speeds-the operator code sets only one dial, for average current. For flux-cored-arc welding, shops use CV or CC types, 300 to 1,500 A, 25 to 50 V, rated 60- to 100-percent-duty cycle. CV types are more popular because wire-feed speed, set before welding, controls welding current. Cc types require a variable-speed or voltage-sensing wire feeder.Gas-tungsten-arc welding (GTAW) requires a constant-current (AC or DC) power supply with a steep aircompressortansasme volt-amp curve to minimize current change for variation in voltage or arc length. They come rated to 1,500 A, 10 to 75 V, at 40- to 100-percent-duty cycle. Most GTAW power supplies come equipped with high-frequency circuitry for arc initiation and stabilization, code gas valves, and cooling-water valves for high-current welding. High-frequency arc start is useful when the maximum open-circuit aircompressortansasme voltage allowed by NEMA standards, 80 to 100 V, will not establish and maintain a stable code arc. Searching for accessories for your air compressor? We offer the best selection of cheap air compressor accessories on the internet. Check out our website for great deales on all of our air compressor accessories!
|