Specifications: Spot Welder Power Supplies

Power Supply Model	IS-120A	IS-444B	ISA-500A	IS-471B
Power Source:	3 phase 480VAC / 440 VAC / 20VAC +10% -15% 50/60 Hz
Output Frequency:	1 kHz / 800 Hz / 600 Hz (selectable)
Output Voltage:	Single Phase 650V, Peak at 480V input
Rated Capacity:	52 kVA at 480 VAC	182 kVA at 480 VAC		325 kVA at 480 VAC
Maximum Primary  Output Current:	200 A (8% duty cycle)	500 A (15% duty cycle)		1000A (12% duty cycle)
Control Systems:	Secondary Constant Current	Secondary Constant Current
	Secondary Constant Power	Secondary Constant Power
	Primary Constant Current (RMS)	Primary Constant Current (RMS)
	Primary Constant Current (Peak)	Primary Constant Current (Peak)
	Fixed Pulse	Fixed Pulse
	Secondary Constant Voltage
Control Modes:	N/A		Forging, Chaining,   Successive	N/A
Weld Schedules:	15 schedules
Timer Settings:	ms Mode	ms Mode		Cycle Mode
Squeeze Delay	0000-9999 ms	0000-9999 ms		000-999 cycles
Squeeze	0000-9999 ms	0000-9999 ms		000-999 cycles
Weld 1	000-600 ms	000-600 ms		00-30 cycles
Upslope	000-400 ms	000-400 ms		00-20 cycles
Cool	000-999 ms	000-999 ms		00-99 cycles
Weld 2	000-600 ms	000-600 ms		00-30 cycles
Downslope	000-400 ms	000-400 ms		00-20 cycles
Hold	000-999 ms	000-999 ms		00-99 cycles
Off	0000-9999 ms	0000-9999 ms		00-99 cycles
Pulses	1-9 and Cycle Mode (see right)	1-9		1-9
Maximum Secondary Current Settings:	0.1 -- 20.0 kA	2.0 -- 40.0 kA		4.0 -- 80.0 kA
Weld Monitors:
Current	00.0-20.0 kA	00.0-40.0 kA		00.0-80.0 kA
Voltage	00.0-9.99 V	00.0-9.99 V		00.0-9.99 V
Power	00.0-20.0 kW	00.0-40.0 kW		00.0-80.0 kW
Pulse Width	10%-100%	10%-100%		10%-100%
Program Unit:	MA-627A (sold separately)
Monitor Unit:	MA-628A (sold separately)
Dimensions (H x W x D):	11 x 7 x 25 inches  (686 x 483 x 1600 mm)	27 x 12 x 20 inches  (1702 x 762 x 1295 mm)		27 x 12 x 26 inches  (1702 x 762 x1664 mm)
Weight:	33 lbs. (15 kg)	99 lbs. (45 kg)		139 lbs. (63 kg)

Specifications: Seam Welder Inverter Power Supplies

Power Supply Model	IS-433B	IS-470B
Power Source:	3 phase 480 VAC  /  440 VAC  /  220 VAC  +10% -15%  50/60 Hz
Output Frequency:	1 kHz  /  800 Hz  /  600 Hz (selectable)
Output Voltage:	Single Phase 650V, Peak at 480V input
Rated Capacity:	182 kVA at 480 VAC	325 kVA at 480 VAC
Maximum Primary Output Current:	500 A (15% duty cycle)	1000 A (12% duty cycle)
Control Systems:	Primary Constant Current
	(PWM RMS Value)
	Primary Constant Current
	(PWM Effective Peak)
	Fixed Pulse
Control Modes:	N/A
Weld Schedules:	7 schedules
Timer Settings:	ms Mode
Squeeze Delay	n/a
Squeeze	0000-9999 ms
Delay	000-999 ms
Weld 1	000-600 ms
Upslope	000-400 ms (included in Weld 1)
Cool	000-999 ms
Weld 2	n/a
Downslope	n/a
Hold	000-999 ms
Off	n/a
Pulses	1-9
Maximum Secondary Current Settings:	1.0 - 20.0 kA	2.0 - 40.0 kA
Weld Monitors:
Current	00.0-20 kA	00.0-40 kA
Pulse Width	10%-100%	10%-100%
Program Unit:	MA-627A (sold separately)
Monitor Unit:	N/A
Dimensions (H x W x D):	27 x 12 x 20 inches  (1702 x 762 x 1295 mm)	27 x 12 x 26 inches  (1702 x 762 x 1664 mm)
Weight:	99 lbs (45 kg)	139 lbs. (63 kg)

Specifications: DC Inverter Transformers

Transformer Model	IT-40	IT-85	IT-130	IT-250
Rated Capacity:	40 kVA at 50%	85 kVA at 50%	130 kVA at 50%	250 kVA at 50%
Maximum Input Voltage:	650 V	650 V	650 V	650 V
Input Frequency:	1000 Hz	1000 Hz	1000 Hz	1000 Hz
Unloaded Secondary Voltage/Turns Ratio:	4.28 V (152:1)	8.9 V (73:1)	13.0 V (50:1)	13.0 V (50:1)
	8.55 V (76:1)	9.5 V (68:1)	13.8 V (41:1)
Cooling Water:	1 gal/min	2 gal/min	4 gal/min	4 gal/min
Dimensions (H x W x D):	6.75 x 5.0 x 14.85 in  (432 x 330 x 965 mm)	6.75 x 6 x 11.9 in (432 x 381 x 762 mm)	10.26 x 6 x 15.5 in (660 x 381 x 991 mm)	10.25 x 7.75 x 19 in (660 x 483 x 1219 mm)
Weight:	60 lbs. (27 kg)	60 lbs. (27 kg)	110 lbs. (50 kg)	130 lbs. (59 kg)

Inverter Welding Delivers Performance and Payback

Courtesy of Miyachi

With quality and production demands increasing, DC inverter resistance welding offers benefits that traditional AC welding cannot address. In the broadest sense, inverter welding offers more flexibility than conventional AC welding. Virtually any application that can be done with an AC weld control can be done with inverter technology.

Inverter Performance Benefits

Many resistance weld failures can be traced to inconsistent secondary welding current. Adaptive feedback systems used in inverter technology utilize pulse width modulation to continuously monitor and adjust the weld current throughout the weld, compensating for non-uniform workpiece resistance, worn electrodes, and power source fluctuations, resulting in extremely consistent weld current delivery throughout every weld. The benefits derived include shorter weld times, lower currents and forces, faster speed and throughput, longer electrode life, less weld splash, and less surface deformation of the part.

Efficient Weld Current Delivery Improves Quality

In resistance welding, a weld joint (or nugget) is formed as weld current flows through the workpieces, encountering different electrical resistanaces and generating heat. AC controls, by definition, cycle weld current on and off twice per cycle. The AC “cycling” can cause embrittlement and irregular nugget formation, hurting weld quality and strength. By contrast, inverter systems deliver current without cycling, thus continuously heating the weldments. Weld times can be adjusted in one millisecond increments. This precise control allows inverter welders to utilize shorter weld times and control how current can be introduced into the parts by “shaping” the current weldform. Lower weld current and less force (compared to AC weld controls) and be utilized to achieve the desired molten state of the weldments for optimal nugget formation.

Hard to Weld Materials

Inverters are capable of successfully welding a broad range of materials. Softer metals, particularly those with high electrical and thermal conductivity are good candidates for inverter resistance welding. Higher electrical conductivity means that higher weld currents must be used. High thermal conductivity requires that the weld current must be delivered quickly to minimize the heat affected zone. Zinc coated galvanized steels also fall into this category.

High Current Output – Small Transformer Package

Compact inverter equipment features small, lightweight welding transformers for use in manual, automated, and robotic (transgun) configurations. In AC resistance welding, higher current outputs generally require extremely large transformers. The physical size and weight of the AC welding transformer is especially critical in transgun configurations, often limiting the current output available. Inverter transformers are often as much as 50% smaller, lighter, and deliver higher current outputs than conventional AC transguns.

Inverter Realities

Inverter performance benefits can result in higher production rates with less time lost to electrode maintenance and changes. According to many manufacturers, weld failures, part rejects, and costly re-works have been dramatically reduced. Shorter weld times, lower weld currents, and balanced line loads, lessen the primary current demand – reducing electrical usage and expense. Adaptive feedback control modes and millisecond programming make precise control over the resistance welding process a reality. DC inverter welding allows for a broader process window to overcome workpiece variances and production changes. This larger process window is one of the primary reasons that inverter welding meets today’s demand for higher quality and delivers such an attractive return on investment.