ESAB Spot/Burnback/Trigger Latch Kit Installation guide

Brand: ESAB

Model: Spot/Burnback/Trigger Latch Kit

Category: Welding System

Type: Installation guide

This optional 3-function module permits using the

Migmaster 251 for spot welding, burnback control to

keep wire from sticking at end of weld, and trigger latch-

ing for long weld runs.

Before installing this kit, make sure all primary in-

put power to the power source is disconnected and/

or lock out procedures are in place.

INSTALLATION

1. Remove and discard the upper blank plate from

the control panel of the Migmaster 251 unit. Re-

tain the 4 mounting screws.

2. Remove the top hinged cover and left side panel

from the Migmaster 251 unit and set them aside.

3. Feed the control wires and the U-shape current

detector assembly of the Spot/Burnback module

through the rectangular hole in the control panel,

and then mount the module using the 4 mounting

screws retained from step 1.

4. Route the control wires through the hole marked

1 in the wire feeder compartment and above the

output studs. Restrain them with cable ties.

5. Remove the jumper plug from the upper right re-

ceptacle on the units main control PC board, and

then connect the control wires from the Spot/

Burnback module to this receptacle.

F-15-359

June, 1998

INSTALLATION & OPERATING INSTRUCTIONS

SPOT/BURNBACK/TRIGGER LATCH KIT

P/N 36694

For MIGMASTER 251 PACKAGE

NOTE: Do not discard the jumper plug. If it becomes

necessary to remove the optional module, the

jumper must be reconnected for proper opera-

tion.

6. Locate trim potentiometer R25 near the top center

edge of the main control PC board. This potenti-

ometer is set at a minimum position at the factory

and will not require any adjustments. However, to

adjust burnback time, using a small screwdriver,

rotate R25 trimpot carefully to get a desired

burnback time.

7. Mount the current detector to the work cable near

the negative (-) stud in the wire feeder compart-

ment. To do this, remove nut and reed switch from

the U shape steel piece. Slip the U shape piece

over the cable and then reassemble reed switch

and nut. Tighten nut until snug. Do not overtighten.

8. Reinstall the left side panel and then the top hinged

cover.

OPERATION

Spot Welding

1. Set the Spot/Std/Trigger Latch to SPOT position.

2. Set the Spot timer dial to the desired setting (0.1 to

5.0 seconds).

3. Use a No. 12 Spot Weld nozzle on your torch .

4. Trim welding wire back so that the end is slightly

inside the nozzle.

Be sure this information reaches the operator.

You can get extra copies through your supplier.

Install

Current Detector

Install

Spot Module

here.

Hole 1

Torch

Cable

Work

Cable

Figure 1 - Migmaster 251, Feeder Compartment (Right Side View)

Main Control

PC Board

Connect control wires

from Spot Module here.

Hole 1

(Ref.)

Figure 2 - Migmaster 251, Left Side View

R25 trimpot (set to min.)

5. Set the Migmaster 251 Voltage and Wire Feed con-

trols to the desired settings. Refer to the Migmaster

251 instruction manual, F-15-357, for other oper-

ating details.

6. Press the torch nozzle squarely on the top plate.

Apply enough pressure to hold the two pieces of

metal firmly together so there is no loose play be-

tween them.

7. Pull the trigger, holding the torch motionless and

firmly. The electrode wire and shielding gas will

be fed to the work, and the arc will be maintained

for the length of time set on the Spot timer of Step

2 above.

8. After the preset time has elapsed, the wire will stop

feeding, the arc will be broken, and the shielding

gas will stop flowing.

A good spotweld will penetrate through both layers

of metal and should have a small nugget on the

reverse side as shown in Fig. 3.

Figure 3. - Cross Section of Good Spotweld

Burnback

The burnback feature provides a time delay at the end

of a weld from the time the torch is released until the

main contactor is deenergized. This delay allows the

welding wire to burn back so it wont stick in the weld

puddle. The Burnback timer dial controls this delay time

from 0.05 to 0.5 seconds.

If the welding wire tends to stick in the puddle at the

end of a weld, increase the Burnback time. On the

other hand, if the wire burns back into the torch tip,

decrease the Burnback time.

Generally, the required time delay depends on the Wire

Speed setting on the Migmaster 251. The faster the

wire feeds into the weld, the greater the time delay will

be required.

Trigger Latch

When the 3-position switch of the module is in the Trig-

ger Latch position, the torch trigger will latch when cur-

rent is detected. The torch trigger can be released af-

ter obtaining the welding arc for long weld runs. To ter-

minate the arc, press and release the trigger again.

NOTE: If the arc is broken with the trigger latched, the

trigger will unlatch approximately 3 seconds

after loss of current detection.

NOTE: Trigger latch cannot be used with the Spool

Gun.

Figure 4 - Schematic Diagram, Spot/Burnback Module

TO MM 251 PCB1 P4

(SEE F-15-357)

SENSOR PROXIMITY ASSY. (S1) - 34372

PC BOARD ASSY. SEQ. CONTROL (PCB1) 31471

(4) BOARD SUPPORT - 950708

(2) POT LIN 250K 2W (R1, 42) - 599670

(2) KNOB - 13730611

PLATE - 32263GY

SWITCH DPDT 3 POS (S2) - 950458

SWITCH SEAL BLACK - 951474

F-15-359 6/98 1M

Figure 5 - Replacement Parts - Spot/Burnback Module, P/N 36694

ESAB Spot/Burnback/Trigger Latch Kit Installation guide

Brand: ESAB

Model: Spot/Burnback/Trigger Latch Kit

Category: Welding System

Type: Installation guide

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ESAB Spot/Burnback/Trigger Latch Kit Installation guide

ESAB Spot/Burnback/Trigger Latch Kit Installation guide

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