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Systematics, Inc. West Chester, PA.  19380

11

FIG. 17.  STITCH WELDING

DIRECTION
OF TRAVEL

30 DEGREES

WORK

SHIELDING GAS

MIG SPOT WELDING ON STEEL

(

PBE250S

 ONLY)

NOTE

MIG Spot Welding is NOT
recommended for aluminum.

1. Trim the electrode wire so the

stickout from the contact tip
will be flush with the nozzle
face, and fit the spot nozzle in
place.

2. Set the VOLTAGE on the welder

around 20 volts, the WIRE FEED
control "8", the MODE Switch to
"SPOT", and the TIME control to
"3", then adjust the controls to
obtain a perfect weld.

3. Locate the torch on the area to

be welded and press the nozzle
firmly against the work to hold
the metals in place.

4. Guard the eyes against stray arc

flash. A weldor’s helmet is not
necessary when spot welding,
however, care must be taken to
avoid looking at the arc.

5. Activate the torch trigger to

start the weld sequence. When
the timer switches off the weld
current, release the trigger but
maintain firm contact between
the torch and work. Wait one
second for the weld puddle to
solidify, then move to the next
spot position. If the wire
"freezes" in the puddle, a quick
squeeze of the torch trigger
will melt it off.

6. To ascertain a good spot weld,

look at the back side of the
welded material. A small melt-
through  of approximately 1/16
inch diameter is ideal.

STITCH WELDING ON STEEL

(

PBE250S

 ONLY)

NOTE

Stitch Welding is used for
very light material.

1. Set MODE Switch to "STITCH".

2. Adjust the TIME control to set

the time the welder is "on" and
feeding wire. The lower the
setting, the shorter the "on"
time and the faster the unit
cycles on and off.

3. Weld using "Continuous Welding"

torch position and direction of
travel.

FIG. 16.  MIG SPOT WELDING

PRESS NOZZLE

FIRMLY

AGAINST WORK

SPOTWELD

NOZZLE

CONTACT

TIP

SPOTWELD

WORK

Summary of Contents for PBE250

Page 1: ...FINEST MIG WELDING SYSTEMS AVAILABLE TODAY THE PBE250REPRESENTSFOURTHGENERATIONTECH NOLOGICAL ADVANCEMENTS THIS SYSTEM IS DE SIGNED AND ENGINEERED TO PROVIDE YOU WITH YEARS OF PROFESSIONAL SERVICE IN...

Page 2: ...TIAL DAMAGES SO THE ABOVE LIMITA TIONS OR EXCLUSIONS MAY NOT APPLY TO YOU THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS AND YOU MAY HAVE OTHER RIGHTS WHICH MAY VARY FROM STATE TO STATE ARC WELDING CAN...

Page 3: ...he electrode wire dips into the pool and causes a short circuit The short circuit current flow causes a rapid temperature rise in the electrode wire and the end of the wire is melted off An arc is imm...

Page 4: ...5 Argon 25 CO2 For Aluminum Bronze Argon For Stainless Steel Argon 2 Oxygen For Flux cored CO2 or Argon CO2 mix GLOBULAR TRANSFER Globular transfer occurs at the intermediate range of 22 to 24 arc vol...

Page 5: ...HICH ARE NOT PROVIDED WITH THE PBE250 1 Full cover welding helmet with proper colored lens shade 9 to 11 depending on operator s pref erence 2 Proper shielding gas and cylin der 3 Leather welding glov...

Page 6: ...N MAKE SURE POWER SOURCE IS UNPLUGGED BEFORE MAKING IN PUT SELECTION CHANGE OVER 3 Attached to the power source s contactor is one 2 two posi tion plug which allows easy selection of input voltages of...

Page 7: ...ng remove the drive roll turn it over and reinstall it on the shaft continued on following page B SIDE FACING IN FOR 023 035 STEEL WIRES C SIDE FACING IN FOR 040 045 STEEL WIRES AND 3 64 ALUMINUM WIRE...

Page 8: ...of the torch approximately six inches CAUTION Keep hands and face away from the front of the torch and do not allow the wire to contact the Work The wire is electrically HOT when the torch trigger is...

Page 9: ...same type and thickness as the material to be welded OPERATING SEQUENCE 1 Make sure that the pieces of metal to be welded are free of grease dirt paint and scale Use a wire brush to remove paint and s...

Page 10: ...J TORCH SELECTOR CABLE Plugs into positive terminal for standard welding operation or negative terminal for straight polarity welding on very light sheet metal or for using flux cored gasless wire K P...

Page 11: ...STICKOUT NOTE When welding steel the ideal position for holding the torch is inclined approximately 30 degrees towards the direction of travel This allows the arc to be seen easily resulting in great...

Page 12: ...any anti spatter material on the torch or base metal and DO NOT attempt to lubricate the aluminum wire in any way Weld contamination will occur unless the wire base metal torch and work area are kept...

Page 13: ...ooking at the arc 5 Activate the torch trigger to start the weld sequence When the timer switches off the weld current release the trigger but maintain firm contact between the torch and work Wait one...

Page 14: ...r This can cause wire feeding problems so a new liner should be installed OPERATING HINTS BURN BACK In the event the welding wire burns back into the contact tip 1 Remove the nozzle from the torch 2 U...

Page 15: ...this unit contact tips M3 T30 etc gas nozzles M3T N50 nozzle insulators M3T B gas diffusers M3T D steel liner 020 030 M103L B steel liner 035 045 M104L N In the event of the failure of any part of thi...

Page 16: ...k torch cable activated for continuity no response Loose or broken connection Check or repair on wiring harness connections Wire feed motor unplugged Plug in motor RC1 Faulty control transformer Check...

Page 17: ...shielding gas Replace tank trigger tank empty activated Loose or broken Tighten or repair no gas flow connections connections but contactor Faulty Gas solenoid Repair or replace operates valve GS valv...

Page 18: ...loser to work Poor connections Check and tighten all connections Faulty diode Test diodes replace D1 D4 faulty diode s See page 17 Heavy spatter Incorrect machine settings Increase heat decrease wire...

Page 19: ...If there is no continuity in either direction the diode is in open circuit condition and must be replaced If there is continuity in both direc tions the diode is in short circuit condition and must be...

Page 20: ...REQUIRED 1 Remove the top cover assembly from the unit 2 Locate the printed circuit board s 3 Referring to Figure 19 locate the trim resistor this is lo cated in the upper right hand corner of the wi...

Page 21: ...W M3 212 TRIGGER ADJUSTING SCREW ONLY M3 213 TRIGGER PIN M3 214 TRIGGER SPRING QUICK CONNECTOR GROUP M3 120 FERRULE M3 301A CONNECTOR HOUSING M3 305A CONNECTOR STEM M3 306 CONNECTOR PLUG WITH SETSCREW...

Page 22: ...t cable is 25 feet in length 35 foot and 50 foot cables are optional The wire speed control knob is built into the gun handle With the following options the MHG7 can also be used to weld steel or stai...

Page 23: ...24 Systematics Inc West Chester PA 19380 NOTES...

Page 24: ...Systematics Inc West Chester PA 19380 25 NOTES...

Page 25: ...26 Systematics Inc West Chester PA 19380...

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