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16
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• Welding current limit can be preset from 5 to 315
amps and is displayed on the Ammeter when not
welding.
• Auto Balance circuitry automatically provides the
proper amount of cleaning and penetration when
AC TIG welding. Manual AC wave balance adjust-
ment is also possible.
• 2-Step/4-Step Arc Start Switch Capability.
• TIG Pulser with On/Off Selection, and Pulses Per
Second adjustment. Background current and duty
cycle are automatically adjusted according to the
peak welding current.
• Fixed preflow time of 0.5 seconds. Preflow time is
eliminated if welding restarts during gas afterflow of
previous weld. This avoids unnecessary delays
when making repeated welds.
• Adjustable afterflow time control.
• Local/Remote current selection.
• Stick/TlG selection.
• Continuous/Start/Off High Frequency selection.
• DC+/AC/DC- Polarity Switch.
• Power Factor Correction for lower input currents and
smaller input wire sizes.
• Remote Receptacle for Amptrol or Arc Start Switch.
• Low Voltage Arc Start Switch Circuit (24 V AC) for
maximum operator safety.
• Gas and optional Water Valves: Inlet & outlet fittings
conform to Compressed Gas Association (CGA)
standards.
• Built-in High Frequency Generator.
• 115 Volt Receptacle with 10 amp Circuit Breaker.
• 220 Volt European (Schuko) type receptacle with 2
amp circuit breaker for water coolers (50/60Hz
machines only).
• Excellent arc starting and stability up through 315
amps.
• High resistance to AC arc rectification.
• No tungsten spitting within current range of
electrode.
• Compact size, requires only a 19 in x 30 in
(485 mm x 760 mm) footprint.
GENERAL DESCRIPTION
The Square Wave TIG 255 is a constant current,
single range square wave AC/DC TIG (GTAW) arc
welding power source with built-in high frequency
stabilization. It also has stick (SMAW) capability. It is
available from the factory in one model only; there are
no factory installed options, only variations in input
voltage and frequency.
The Square Wave TIG 255 includes advanced
features such as Auto-Balance™, 2-Step/4-Step Arc
Start Switch operation and a TIG pulser. In addition,
fixed preflow and variable afterflow timers are
included for shielding gas and cooling water control.
Recommended Processes And
Equipment
The Square Wave TIG 255 is recommended for the
TIG (GTAW) and stick (SMAW) welding processes
within its output capacity of 5 to 315 amps, on both
AC and DC polarity. It is compatible with all Magnum
TIG accessories (see Accessory section in this
manual), as well as many industry standard
items, such as TIG torches, hoses, and water coolers.
Operational Features and Controls
The Square Wave 255 has the following controls as
standard: TIG 2-Step/TlG 4-Step/Stick mode
selection, Local/Remote current control selection,
Continuous/Start Only/Off high frequency selection,
Auto/Manual AC wave balance selection with the
manual wave balance adjustment, TIG pulser On/Off
selection with frequency adjustment, afterflow
adjustment, and DC+/DC-/AC polarity selection.
Design Features and Advantages
• Designed to NEMA EW-1 & International IEC-974
Standards.
• Single output range of 5-315 amps covers the
majority of all TIG welding applications.
• Solid State Output Contactor: no noise, no parts to
wear.
• Digital Ammeter and Voltmeter for precise readings
from 5 to 315 amps welding.
OPERATION