ESAB Digimatic II Four Schedule Microprocessor Control Troubleshooting instruction

INSTRUCTIONS for

F-15-070-A
April, 1994

DIGIMATIC II

FOUR SCHEDULE

MICROPROCESSOR

CONTROL

P/N 31551

FOR AUTOMATED MECHANIZED

MIG WELDING

SPECIFICATIONS

Input Power Required 1A., 115 volts, 50/60 Hz, 1 ph
Height 15.5-in. (394mm)
Depth 8-in. (200mm)
Width 13-in. (330mm)
Weight (approx.) 20-lbs. (9.1kg)

In the same way that Digimig changed the face of semiautomatic mig welding, the Digimatic II's
microprocessor accuracy and flexibility revolutionized Automatic Mechanized MIG Welding. The
Four-Schedule Digimatic II is truly "the first Intelligent Mechanized Mig System".

FEATURES/BENEFITS

Presettable Wire Feed Speed (IPM) and Volt­age (VOLTS) ...Provides ability to easily and
accurately preset the exact welding param­eters desired, before the welding sequence
begins!

Patented Microprocessor Controlled Closed
Loop System ...Provides most accurate means
of maintaining wire feed sped (amperage) and
welding voltage. The microprocessor com­pensates for deviations in ambient tempera­ture, primary voltage fluctuation and changes
in arc dynamics or wire feed force conditions,
to assure that preset parameters are main­tained.

Four Presettable Welding Schedules...Unlike the origi­nal single- schedule Digimatic II, this unit allows you
to preset up to four (4) completely different welding
schedules that can save control setup time and im­prove productivity. By presetting four of your most
common welding requirements, all you have to do is
switch weldments and select the appropriate sched­ule for that particular job.

Eight Presettable Conditions Per Schedule...In se­quence, including, PREFLOW, STRIKE, START,
WELD, CRATER, ANTI-STICK (Burnback),POSTFLOW
and WIRE RETRACT. Total weld condition
presettability means improved weld quality and pro­ductivity.

These INSTRUCTIONS are for experienced operators. If you are not fully familiar with the principles of operation
and safe practices for electric welding equipment, we urge you to read our booklet, "Precautions and Safe
Practices for Arc Welding, Cutting and Gouging," Form 52-529. Do NOT permit untrained persons to install,
operate, or maintain this equipment. Do NOT attempt to install or operate this equipment until you have read and
fully understand these instructions, contact your supplier for further information. Be sure to read the SAFETY
PRECAUTIONS on page 3 and 4 before installing or operating this equipment.

1

CONTENTS

Specifications ...................................................................................................................... 1

Features/Benefits ............................................................................................................. 1/5

Safety Precautions ........................................................................................................... 3/4

I. INSTALLATION .................................................................................................................. 5

A. Required Equipment ....................................................................................................... 5

B. Optional Accessories ...................................................................................................... 6

C. Mount/Connect Equipment.............................................................................................. 8

II. CONTROL FUNCTIONS .................................................................................................... 9

A. Front Panel Controls ....................................................................................................... 9

B. Inside Panel Controls .................................................................................................... 10

C. Additional Program Controls ........................................................................................ 12

III.PRESETTING WELDING SCHEDULES .......................................................................... 12

IV.WELDING SEQUENCE ................................................................................................... 14

V. TROUBLESHOOTING...................................................................................................... 15

VI.REPLACEMENT PARTS DATA ....................................................................................... 21

Figure 1 - Interconnection Diagram .................................................................................... 8

Figure 1-A. - OM-48 J-Governor Hookup ............................................................................ 9

Figure 1-B - Plumbing Box Hook-up .................................................................................... 9

Figure 2 - Front Panel Controls ........................................................................................ 10

Figure 3 - Inside Panel Controls ........................................................................................ 12

Figure 4 - MPU Dip Switch Location .................................................................................. 13

Figure 4-A - Typical Time Parameter Setup ...................................................................... 14

Figure 5 - Typical Weld Condition Sequence Per Schedule .............................................. 16

Figure 6 - Sequential Troubleshooting Flow Diagram ........................................................ 20

Figure 7 - Control Assy. Replacement Parts/External ....................................................... 21

Figure 8, 9 - Control Assy. Replacement Partts/Internal .................................................... 22

Figure 10 - Plumbing Box Replacement Parts ................................................................... 23

Figure 11 - Control Schematic Diagram ............................................................................ 24

Figure 12, 13 - Control Wiring Diagrams ...................................................................... 25\26

2

345

Sure Start Interlock...To assure troublefree starts,
the Digimatic II has an interlock circuit which will
not allow wire feed to initiate unless the power
supply contactor is closed and STRIKE voltage is
present.

Presettable STRIKE Time...Assures safe consis­tent starts. If for any reason the Strike Time is
exceeded (wire does not feed or misses the work)
the Digimatic II will automatically shut down and
flash the preset STRIKE TIME in the VOLTS dis­play window.

Arc Detector Circuit...Senses that both Welding
Voltage and Amperage are present to facilitate
transfer from Strike to Start condition param­eters, and also provide a signal to initiate travel of
a carriage or fixture.

Automatic Controlled Shutdown ...To assure that
all welding is performed only at the preset param­eters, Digimatic II will automatically shutdown in
the rare event that either voltage or wire feed
speed cannot be maintained during the welding
sequence.

The Digimatic II will always sequence through a
controlled shutdown including dynamic motor
brake, anti-stick and postflow. Simultaneously,
the cause is indicated by a flashing VOLTS or IPM
display.

Remote Control Capabilities...To provide easy
interfacing with fixtures, the Digimatic II incorpo­rates remote Start/Stop and Wire Inch Capabili­ties which can be controlled by switches or relays
at a central control panel.

Single or Repeat Timed Weld Capabilities ...Be­cause the Digimatic II incorporates a Repeat weld
timer, adjustable up to 999 cycles (16.5 seconds),
the Digimatic II offers more than conventional con-
tinuous seam, or Single Times welding capabili­ties. It can also be preset for Repeat Timed skip
or stitch welding applications.

Automatic Adaptive Anti-Stick or Manual
Burnback Time Feature...A patented adaptive anti­stick circuit automatically adjusts the same
amount of wire burnback, regardless of wire size,
speed or voltage. Or, you can manually preset a
Burnback Time to specifically suit a specialized
application.

Missweld Time...depending on the criticality of
the weld, this feature allows you to preset the
number of cycles of arc time that can reasonably
be missed during a welding condition and still
produce an acceptable weld. If more than the
allowable number of arc cycles are missed, the
unit will shutdown/abort and flash the preset
Missweld Time cycles in the IPM display window.

Wire Retract Feature...Provides the ability to pre­set a Wire Retract time which will assure that the
wire is well removed from the work area and not
subject to possible postweld bending due to
contact with the workpiece or fixture.

Independent Presettable Cold Wire Inch...To

reduce down time for reloading welding
wire, the Digimatic II cold wire Inch
sped can be independently adjusted (up
to 999 ipm) without affecting any of the
other preset welding conditions.

Circuit Protection...Resettable cir­cuit breaker for 115 VAC, 50 or 60 HZ
input power minimizes down time and
maintenance.

Unique Diagnostic Set-up/Test
Circuit...Provides the ability to to­tally test the Digimatic II electronics
as well as run it through a complete
timed sequence of preset weld conditions
without actually welding.

Individual Digital Meters Provide Large 1/2-in.
Display of Voltage And Wire Feed Speed IPM...After
the arc is struck, the meters automatically trans­fer from preset to display of actual VOLTS and
IPM for each welding condition as the Digimatic II
sequences through the preset welding sequence.

Arc Hours Readout...This unique feature pro­vides a direct measure of productivity by accu­mulating and displaying, upon command, actual
welding Arc Hours.

I. INSTALLATION

A. EQUIPMENT REQUIRED

1. Digimatic II Four-Schedule Control Assy. P/N

31551.

2. EH-10A Digital Welding Head (20-999IPM). The

welding head is composed of three basic units; a wire
feed motor- tachometer unit, a gear reduction unit, and
the accessory support assembly. This control (4-sched­ule) is only usable with a EH-10A Digital Welding Head,
and either of two welding head (following) are available
for use. The wire sizes accommodated are:

Hard ................................ .030 -1/8-in. (.8 - 3.2mm)

Soft ............................... .030 - 3/32-in. (.8 - 2.4mm)

Flux Core ...................... .045 - 1/8-in. (1.2 - 3.2mm)

5. Welding Torch. A mechanized mig welding torch
having a rated capacity suitable for the welding appli
cation, such as:

a. ST-12 Water-Cooled Torch (for currents up to 700

amps) P/N 46V59, or—

b. ST-21M Water-Cooled Mechanized Torch (for cur-

rents up to 600 amps.) P/N 690509, or—

c. MT-500M Air-Cooled Torch (for currents up to 500

amps) P/N 17705.

6. Power Supply Control Cable (J1) Assembly.

Depending on the type of power supply used (trans­former- rectifier/SCR, or inverter), one of the following
control cables is required.

a. Two Roll Drive EH-10A Head - P/N 600416. This

head provides wire feed speeds from 20 - 999 IPM
using a 40:1 gear reduction ratio, and a two-roll acces­sory support wire drive. The motor-tachometer power
and control leads are provided by a pair of 52 inch long
cables connected to a 5-pin amphenol. For further
information refer to booklet L12-873.

b. Four Roll Drive E-10A Head - P/N 600417. This head

is the same as P/N 600416, except that it incorporates
a four- roll accessory support wire drive assembly.
For further information, refer to booklets F12-873
and F12-821.

NOTE: If the motor direction is to be changed, inter-

change the blue and grey wires on the reversing
relay terminals R-9 and R-7 respectively.

3. Feed Rolls. Select the proper feed roll, for the wire
size to be used, from the data provided in booklets
F12- 873 and F12-821.

4. Constant Voltage Power Supply. In order to use the
Digimatic II Control, it must be operated with
C.V. power supplies designed with “electroni­cally controlled arc voltage regulation” , such as: *

a. 12-conductor control cable with 14-pin amphenol

plug each end for transformer-rectifier/SCR power
supplies such as VI-450*,ESAB-450*-650’s*, -450
Pulse*, etc.—order one of the following cables:

P/N 30780, 30-ft. long assembly.
P/N 30781, 60-ft. long assembly.

7. Shielding Gas Regulation. A gas regulator/flowme­ter and fitted hose are required to bring gas to the
torch, such as:

a. R-5007 Argon Regulator/Flowmeter, P/N 998124.
b. Heavy Duty Gas Hose, P/N 19416 (12-1/2-ft.), or P/

N 19415 (25-ft.).

c. Gas Hose Coupling, P/N 11N17.

8. Water Cooling Requirements. When using a water
cooled torch (ST-12 and ST-21M), the following are
required to supply and drain the cooling water:

a. Water Hose, 12-1/2-foot, P/N 40V76—or,
b. Water Hose, 25-foot, P/N 406196.
c. Water (In/Out) Adaptor (Connects hose to 1/4

NPT), P/N 11N16.

d. Water Hose Coupling, P/N 11N18.

VI-450A Mig Power Supply, P/N 680180; or, ESAB
450 Power Supply, P/N 678530; ESAB 450 Pulse, P/
N 679981; or, ESAB 650CV/CC Power Supply, P/N
677910; or ESAB 650CV Power Supply, P/N 679321;
or ESAB 400i, P/N 31920, or SVI-450i, P/N 31950.

*Some of these power supplies provide two (2) Posi-

tive output Slope terminals—Flat and Steep. The
micro- processor control is factory set to operate
from the power supply Flat slope output terminal.
If the power supply Steep slope output terminal is to
be used, you must check and readjust the Hot Start
as described in Section III-I-1, in order to provide
the best arc starts possible.

B.OPTIONAL ACCESSORIES

1. Digital D.C. Ammeter Kit, P/N 679111. This kit

permits direct visual indication of welding current up
to 999 amps d.c., and is available as a field
installed option. The kit is designed for easy snap­on/plug-in installation and consists of an LED Display
P/C Board (P/N 675284), an Ammeter Control P/C
Board (P/N 675334), and assorted mounting hard­ware—for installation refer to booklet L14-220.

2. Control Cable Kit, P/N 600412. This kit consists of
three (3) separate cable assemblies which can
beused to signal various external control functions
provided from or to the Digimatic II, as shown in Fig.
1 and as follows:

6

a. Gas Cable Assy. P/N 678036. This cable ener-

gizes an external solenoid to provide gas shielding
during the preflow, welding, and postflow cycles.
The assembly is a 25-foot, 2-conductor cable with
a 3-pin amphenol plug to self-lead wire connec­tions.

b. Remote Start Output Cable Assembly, P/N

678037. This cable provides connection for Weld­Start operation from a remote maintain
contact switch. The assembly is a 25-foot, 6­conductor cable with a 6-pin amphenol plug to
self-lead wire connections.

c. Remote Inch/Arc Detector (Carriage) Cable As

sembly, P/N 678038. This cable provides connec-

tion for Cold- Wire Inch operation from a remote
momentary contact switch, power (115 VAC) to
energize a remote solenoid for continuous water
cooling, and also provides an Arc Detector signal to
initiate a carriage or fixture drive mechanism. The
assembly is a 25-foot, 8-conductor cable with a 8­pin amphenol to self-lead wire connections.

3. Motor-Tachometer Extension Cable Assem-

bly, P/N 996808. This assembly allows you to ex-

tend the welding head location using a 25-foot, 6
conductor cable (1-conductor not used) with a 5-pin
amphenol plug (which connects to the control’s J2
receptacle) and an 5-pin amphenol receptacle (which
connects to the EH-10’s plug).

4. Gas and Water Solenoid Valves, P/N 636386. Used
to control flow of shielding gas and cooling water.

5. Reel/Spindle Support, P/N 634288. This support
arm is utilized to mount either wire spools or coils. Will
mount to any fixture or to the OM-48 carriage when
the required support adaptor P/N 996498 is used.

6. Spindle Assy., P/N 948259. Mounts to Item 5 above
and is used for 12-in. diam. spools.

7. H.D. Spoke-Type Wire Reel, P/N 19V89. Mounts to
Item 5 above and is used for 65 lb coils.

8. Spool Enclosure Kit, P/N 600240, covers and pro­tects 12-in. spools from dust and moisture.

9. WC-5B Coolant Recirculator, P/N 19947 (F- 14-

422)

For use with water cooled torches such as the ST-12.
A three-gallon tank provides 1.8 gal/min. at 60
psi pump capacity , using 5.4 amps, 115 volts, 60 Hz
input.

10. OM-48 Carriage/J-Governor Packages.

NOTE: The Digimatic II is primarily designed to interface

with fixture builder controls as shown in Fig. 1.

However, it can be connected to a J-Governor/
OM-48 Carriage package. The OM-48 is avail-

able in two different speed ranges, P/N 01E52
with a 4 - 112 IPM travel speed range and P/N
01E54 with a 2 - 56 IPM speed range. Both pack­ages include a solid state J-Governor for speed
control. The Digimatic II inch/arc detector cable
P/N 67803 is required to connect the control to
the J-Governor. Carriage track is not provided
with the OM-48 packages but, is available in ten
foot (10') lengths under P/N 38V16. An optional
J-Governor digital travel speed meter P/N
14292 is available as a special customer or­der.

Refer to Section I-C and Figure 1A for OM-48/J­Gov. wiring hook-up.

11.Plumbing Box, P/N 677261.

NOTE: The Digimatic II is primarily designed to interface

with individual gas and water solenoid opera­tions commonly used in most fixture builder
welding applications as shown in Figure 1.How­ever, with some field-modification (to obtain
the desired type of control), the Plumbing Box
can be adapted to provide a convenient work­ing companion with the Digimatic II control.

The plumbing box assembly contains the
solenoid valves which provide shielding gas
and cooling water control. It is also equipped
with a pressure switch in the water line which
(if connected) will shut down the welding
operation when the water supply is inade­equate. Depending on how the cooling water is
to be controlled. Automatic or Continuous,
one of the following interconnecting setups are
required:

a. For Automatic - Gas and Water operation,

order cable assy. P/N 678036.

b. For Automatic-Gas and Continuous - Water

with Pressure Switch operation, order cable
assemblysP/N 678036 and P/N 678037.

Refer to Section I-C for installation instructions, and
Figure 1-B for Plumbing Box/Digimatic II wiring modi­fications and hook-up.

C. MOUNTING/CONNECTING THE EQUIPMENT

Since the operating controls are mounted on and
inside the Digimatic front panel, the box should be
located so that the meters and controls are within
easy reach of the operator. The control can be
mounted on a side-beam carriage or other vertical
surface by using the mounting holes provided.

7

Figure 1 - Interconnection Diagram

WELDING OUTPUT CABLES ARE SHOWN HOOKED UP FOR

*

D.C. REV POLARITY - IF D.C. STRAIGHT IS DES-SIRED,
INTERCHANGE THE WELDING CABLES AT THE POWER
SUPPLY OUTPUT TERMINALS.

DEPENDING UPON THE TYPE OF WELDING HEAD USED,
& ITS LOCATION - ORIENTATION IN YOUR PARTICULAR
INSTALLATION, YOU MAY NEED TO REVERSE THE MOTOR
LEADS IN THE CONTROL TO ESTABLISH PROPER WIRE
FEED DIRECTION TO DO THIS, INTERCHANGE THE BLUE
AND GREY WIRES ON THE REVERSING RELAY TERMINALS
R-9 AND R-7 RESPECTIVELY.

8

For complete Interconnection Diagram of the
Digimatic II Control with all required and/or optional
related accessories, see Figure 1. For additional
interconnection and wiring of specific optional ac­cessories see the following:

1. For specific hook-up of the Digimatic II with OM-48

Carriage/J-Governor packages see Figure 1-A.

2. For specific hook-up of the digimatic II with Plumbing
Box for torch shielding gas and cooling water control
interconnection and wiring modifications, see Figure
1-B and the following instructions.

a. For Automatic Gas and Water operation, connect

2/c cable (P/N 678036) from J5 receptacle to
Box terminals T1-1 and T1-2. Customer must
supply and add jumper wire between Box termi­nals T1-1 and T1-3 (refer to Fig. 1B).

b. For Automatic - Gas and Continuous - Water

operation, connect 2/c cable (P/N 678036) from J5
receptacle to Box terminal T1-1 and T1-2, Do not
add jumper wire. Disconnect water solenoid
(WSV) wires from terminal T1-2 & T1-3, and re­reconnect WSV wires to an external (customer
supplied) source of 120 VAC power, as shown in
Fig. 1-B.

c. If Automatic - Gas and Continuous - water with

Pressure Switch Control is desired, repeat all
steps in 2-b above, and add the following: 1.)
Disconnect wire from N/C contact of Pressure Sw.
and recon nect it to the N/O contact, as shown
in Fig. 1-B; 2.)Connect 6/c cable (P/N 678037)
from receptacle J4 asfollows: Blu. wire to T1-4 and
Orn. wire to T1-5; 3.) Disconnect insulated jumper
plug between J4-E and -F inside of control cabi­net, see Fig. 1-B.

Figure 1-A, OM-48/J-Governor Hook-Up

Figure 1-B - Plumbing Box Hook-Up

9

II. CONTROL FUNCTIONS

A. FRONT PANEL CONTROLS

For location of control features refer to Fig. 2.

1. Power Switch. Pulling-out the mushroom-style red

button of this switch turns power on in the control as
indicated by the illuminated display windows. To turn
power off , simply push-in the red button and the dis­play windows and control will deenergize.

A

6a

A

6b

A

7

A

6c

the preset times (in cycles) for gas preflow and gas
postflow respectively.

b. After starting the welding sequence—if an abort

shutdown condition occurs (indicated by flash­ing digital display), the Purge/Reset rocker can
be actuated and the control will automatically reset
for a new start.

3. Schedule Select Switch. This four-position rotary
switch allows you to program and select Schedule No.
1 and program (using the Condition Selector, section
II-B-1) a complete welding sequence for a particu­lar application. All of the remaining schedules (No. 2,
No. 3 or No. 4) can be programmed in the same
manner for each different welding application.

4. Inch Up-Down Rocker. This switch is used to cold
inch the wire, up or down, as a preset speed which
you have programmed on the inside panel (II-B-2-b).

IMPORTANT: Cold inching is only possible when the
weld Start-Stop rocker switch is in its stop (or off)
position.

A

1

NOTE: Immediately after the control is turned on,

A

8

Figure 2 - Front PanelControls

a number (e.g.:3) will appear in the IPM read­out window and will only be displayed for 1­second. This information identifies the cur­rent program (E-PROMS) used in your con­trol. When a Program is changed,the new E­PROMS will automatically indicate a 2,3,etc.
to identify the program number being used.
If a revision is made to an existing program,
a decimal number .1,.2,.3, etc. indicating
the numerical revision will also appear in
the VOLTS readout window simultaneously.

A

2

A

4

A

3

A

5

5. Start-Stop Rocker. This two-position (no neutral)
switch initiates the welding sequence when placed in
its START position; and, depending on the type of
welding—Continuous Seam or Timed, terminates the
welding sequence in its STOP position as follows (for
typical setup procedures, refer to Section IV-F):

a. Continuous Seam welding applications. The stop

signal does not immediately terminate the weld-
ing sequence, it only terminates the weld condition
parameter. The sequence then transfers to the
remaining condition parameters (crater fill,
burnback, postflow/retract).

b. Single or Repeat Timed welding applications.

Although the stop signal is not normally used for
timed-welds, you may wish to prematurely termi­nate a burn-thru or unstable weld condition. When
the stop is used; all welding action (including
crater-fill) will terminate, except burnback and
postflow/retract).

6. Digital Readout Windows. Three individual 3- digit
windows labeled AMPS (optional ammeter), IPM and
VOLTS are provided to display actual welding current,
preset or actual welding parameters (wire feed speed
and welding voltage) and time parameters as follows:

2. Gas Purge/Reset Rocker. A momentary on switch,
this rocker provides a dual function when actuated.

a. Prior to starting the welding sequence, it

actuates the gas solenoid and lets you purge
the shielding gas line of the torch. At the same
time, the IPM and VOLTS windows will also display

a. AMP Digital Readout. This window is nomally

blank unless the optional Ammeter Kit is provided
to monitor actual welding current. When installed,
the window displays D.C. current (AMPS) in a
range from 0 - 999 amperes in one amp incre­ments.

10

b. IPM Digital Readout. This window is primarily

used to display wire feed speed (IPM) for each of
the four welding conditions(Strike, Start, Weld, and
Crater) during a typical welding sequence. De­pending on the position of the inside condition
selector switch (functionally defined in II-B); the
IPM window displays actual and/or preset wire
feed speed in a range from 20 to 999 inches­per-minute, in one-inch increments for each weld
condition in the program sequence.

* With power turned ON, but not welding, the IPM win-

dow will continuously read the Preset STRIKE Condi­tion wire speed setting. When the arc is struck, the IPM
window will then continuously read the Actual welding
wire speed as the weld conditions cycle thru the weld­ing sequence.

In addition to the above, and using the Condition and
Time selector controls on the inner panel (functionally
defined in II-B), this window can also display the follow­ing programmed
times:

- PREFLOW. Shielding gas time from 0 to 999
cycles, (16.5 sec.) in one cycle increments (60
cycles per second).

- START TIME. Start time duration is factory preset
at 6 cycles, and can be increased up to 999 cycles,
in one cycle increments.

- WELDTIME. Weld condition duration for
timed-welding (must be set to zero for Continu­ous-Seam Welding), from 1 to 999 cycles, in
one cycle increments.

- CRATER TIME.Crater fill duration, from 1 to
999cycles, in one cycle increments.

- MISSWELD TIME. Presets the number of cycles
of arc time that can reasonably be missed (from 1
up to 999 cycles) during the WELD condition and
still produce an acceptable weld. If the number of
missed cycles match the preset cycles, the unit will
abort. Since the number of missed cycles to be
preset is based upon many variables, the re­quired setting for a given application
obviously involves good judgment and technique.
As an example, to set up a critical 45 cycle
spot weld, you might want to preset
no more than 5 cycles of missweld a r c
time. Be careful not to make the missweld time too

short, otherwise nuisance aborts will occur. If
this feature is not desired, preset
the time for zero cycles.

- INCH PRESET. Cold wire inch speed from 50 to
999 inches-per- minute, in one inch increments.

c. VOLTS Digital Readout. This window is primarily

used to display arc voltage (VOLTS) for each of the
four welding conditions (Strike, Start, Weld, and Cra­ter) during a typical welding sequence. Depending on
the position of the inside Condition Selector switch
(functionally defined II-B); the VOLTS window dis­plays actual and/or preset arc voltage range from
12 to 50 vdc, in one-tenth (0.1) volt increments, for
each weld condition in the program sequence.

* With the power turned ON, but not welding, the VOLTS

window will continuously read the Preset STRIKE
condition voltage setting. When the arc is struck, the
VOLTS window will then continuously read the Actual
welding voltage as the weld conditions cycle thru the
welding sequence.

In addition to the above, and using the inside "Condition"
and "Time" selector controls (functionally defined in II­B), this window can also display the following pro­grammed times:

- POSTFLOW. Controls time for gas postflow after
the arc extinguishes from 0 to 999 cycles.

- STRIKE TIME. Preset time period allowed for the wire
to come down and hit the plate during the Strike
Condition. If the wire does not strike the plate within
the allowed time period, the Digimatic will automati­cally shutdown, and flash the strike time in the
VOLTS display window. Simultaneously, it also pro­vides an abort output signal to stop carriage or
fixture travel. Time range is factory preset for a
minimum of 20 cycles and can be increased in one
cycle increments.

* The strike time setting is dependent upon the strike

IPM setting. The lower the speed, the longer the strike
time needs to be, otherwise nuisance shutdowns will
occur.

- BURNBACK TIME. Manually adjustable burnback
time period which when preset will over-ride the
automatic adaptive anti-stick feature. This time pe­riod can be set in one cycle increments. When set to
zero , the Automatic Adaptive Anti-Stick feature will be
operational.

- REPEAT TIME (or Pause Time). Time period preset
between timed-welds from 1 to 999 cycles, in one
cycle increments.

- RETRACT TIME. At the end of the anti-stick se­quence and during the postflow cycle, the wire feed
motor will reverse for automatic wire retract for a
preset time period. A setting of 10 to 30 cycles is
recommended to prevent excessive withdrawal of
the wire into the contact tip. If a normal stop is
desired, preset this time for zero cycles.

11

- ARC HOURS. Selectable display (record) of accumu­lative welding time in one tenth of an hour increments.
After 99.9 hours it will automatically return to zero.

7. Welding Condition (LED) Lights. These lights
are labeled START, WELD, and CRATER, and they
energize individually as the welding program se­quences through each of these weld conditions.
Prior to the Start, and after the Crater Conditions,
none of these lights will be on .

8. Reset Circuit Breaker. A seven (7) ampere
circuit breaker provides protection to the 115 volt
control circuit and the wire feed motor. If an overload
occurs, the breaker will trip and suspend all
operation. To restore service, simply depress the
breaker button on the front panel.

B. INSIDE PANEL CONTROLS

For location of internal control features, refer to
Fig.3

label, but is the required position used for pre­setting the Missweld and Retract Time features.
The sixth position of this selector, labeled RUN, is
the normal operating setting used after the
control is fully programmed and ready for
use. The IPM and VOLTS parameters, for each of
the following welding conditions, are preset
using the INC./DEC. toggle located directly

- STRIKE. This condition sets the desired ap­proach speed of the wire before striking the
workpiece, and the open-circuit voltage needed
to control the short-circuit current for arc initia­tion.

- START. This condition can be used to set an
appropriate wire speed and voltage parameter
to create a hotstart to help stabilize the arc (for
its preset time) prior to the weld cycle.

- WELD. This condition sets the desired wire
speed and voltage used during the actual weld
cycle.

1. Condition Selector. This six-position rotary switch is
used to select two sets of parameters, Welding and
Timing, for each of the four available schedules:

a. Weld Parameters. The selector’s primary func-

tion, when used with the appropriate Inc./Dec.
toggle, allows you to preset and display (see II-A­6-b & c) the wire feed speed (IPM) and voltage
(VOLTS) weld parameters for its first-four posi­tions labeled—STRIKE, START,WELD, and CRA­TER. The fifth position of this selector has no

B

1

- CRATER. This condition allows you to set a
higher or lower weld speed and/or voltage
(for a preset time period), depending on the
welding condition needed, to regulate the weld
termination size or crater-fill appearance at the
end of the weld.

b. Time Parameters. The secondary function of this

selector is to setup the Time parameters located
within the charts adjacent to each of the weld
conditions. These times are preset by using the
Times/A.H.-Inch Selector (following).

2. Times/Arc Hours-Inch Preset Selector. This two
position, momentary on , toggle must be actuated in
order to preset or change the following parameters:

a. Time Functions. This position actuates the

times-parameters for the sequences shown in
the chart beneath each digital display window.
These sequences are preselected by positioning
the Condition Selector to the pair of time-param­eters to be programmed from its Strike, Start,
Weld, and Crater settings. To check or observe the
time settings, actuate the TIMES position; and to
set or change the settings, simultaneously
operate the INC/DEC toggle switch directly below
the parameter (chart) being set—the time setting in
cycles will appear in its digital display. The times­parameters which can be programmed in each
display window are shown in Figure 3, and were
previously described in Section II-A-6-b (IPM
window) and Section II-A-6-c (VOLTS window).

B

4

Figure 3 - Inside Panel Controls

B

2

B

3a

B

3b

b. Arc Hours-Inch Preset Function. This switch

position operates in the same manner as the Times
function position; except that it only actuates the

12

programs to preset the Cold-Inch speed parameter
and to monitor or reset the accumulative Arc­Hours (welding) time.These functions are
preselected by positioning the Condition Selec­tor to its Run setting. To checkor monitor these
parameters actuate the A.H.- INCH position;
and to set or zero the data, simultaneously operate
the INC/DEC toggle switch directly below the func­tion being set. The cold-inch parameter will appear
in the IPM window, and the arc-hours time will
be shown in the VOLTS window.

NOTE: Actuating this position (Arc Hours/Inch Preset)

during an actual weld allows you to check the
factory-preset numbers that will determine
the quality of starts (hot, cold, etc.) for your
preset welding condition. These numbers are
preset to provide optimum starting characteris­tics required for most welding applications. This
is a diagnostic tool available to the experience
operator or serviceman and need not be acti­vated during a normal operation unless you
are experiencing weld starting problems, or
weld condition (speed and/or voltage) aborting
problems. The factory- set starting condition
is represented by numbers that are displayed,
on command, in the digital IPM and VOLTS
windows. For good welds and starts, these
numbers should be in a range from 105 to 115
(with 110 being the norm) in the IPM window,
and from 90 to 100 (with 95 being the norm) in
the VOLTS window. If your weld starts are not
acceptable, please refer Section III-I-1 for a
simple adjustment procedure that will enhance
good starting. If you are experiencing inordinate
speed and/or voltage aborts, please refer to
Section V-G (Troubleshooting) for checking and
resetting servo functions.

and also the following; Postflow (time), Strike Time,
Burnback Time, Repeat Time, Retract Time and to
zero (dec.) the Arc Hour accumulation. By setting
and/or operating the appropriate Control Selector
(see B-1 and -2 above), each parameter setting will
be displayed in the digital window directly above
this toggle.

4. TEST Toggle Switch—AMPS and VOLTS. As the
title implies, these two toggles simply provide a conven­ient way of test-sequencing all of the program para­meters to either diagnose a problem or to
demonstratethe control assembly without actually
striking a welding arc. A complete set of actual
weld parameters must be preset for this test except
for the following: all voltage conditions and missweld
time parametersmust be set to zero—otherwise an
abort will occur.

To do this, place the two-position "Volts" toggle into
its TEST position—the WELD position being the loca­tion for normal operation. The Volts-Test position
does two things: first, it safely disconnects the actual
contactorcircuit in the power supply; and second, it
provides a 12-volt signal to simulate the arc voltage
required to sequence the welding cycle.

With this accomplished; open up the accessory sup­port to release wire feed pressure, and place the
Start- Stop rocker on the front panel into its START
position, and the control will sequence thru the
programmedPreflow time and enter the Strike condi­tion.

Make sure that the Strike time is set long enough to
give you ample time to operate the Amp test toggle—
a setting of 200 cycles is recommended for Strike
time.

3. Inc./Dec. Toggle Switches. A control toggle (two
position, momentary on ) is provided below the IPM
and VOLTS digital display windows. These two toggles
are used to preset the individual welding condition
and time-sequence parameters desired for the
welding operation, as follows:

a. IPM-TIME Increase/Decrease Control. This toggle

switch is used to set and/or vary wire feed speed
(IPM) for the required weld conditions , and also
the following; Preflow (time), Start Time, Weld
Time, Crater Time, Missweld Time and Inch Pre­set (ipm). By setting and/or operating the appro­priate Control Selectors (see B-1 and -2, above),
each parameter setting will be displayed in the
digital window directly above this toggle.

b. VOLTS-TIME Increase/Decrease Control. This

toggle switch is used to set and/or vary the arc
voltage (VOLTS) for the required weld conditions,

Figure 4 - MPU "Dip Switch" Location

13

During the Strike condition; you must actuate the
momentary "Amps" toggle to its TEST position, to
simulate closure of the arc/current detection circuitry
that verifies the arc has initiated. This action automati­cally allows you to enter the timed Start condition, and
the subsequent Weld, Crater, etc., conditions to evalu-

ate and/or demonstrate the welding sequence.

NOTE: The momentary WELD position of the Amps

toggle has no significance in the Test proce­dures. The normal spring-return center posi­tion, and/or its toggled Weld position essen­tially perform the same function.

C. ADDITIONAL PROGRAM CONTROLS

The MPU (microprocessor) board incorporates an
integral 4-rocker/position dip switch (see Fig. 4)
that is primarily used for internal program func­tions. Switch positions No. 1, No. 2, No. 3 and No. 4
are factory-set in the open (or off) position and must
never be changed.

III. PRESETTING THE WELD SCHEDULE(S)

Remember, the front panel SCHEDULE SELECT
switch allows you to preset a complete and different
welding program for each of the four (4) available
schedules. To preset a typical schedule, do the
following.

A. Pull the Power button out to energize the control, and

then place the Schedule Select switch to position No.

1. The control is now operationally ready to preset a
Schedule No. 1 welding sequence program as des­cribed in steps B thru I following:

NOTE: Upon completion of Schedule No. 1, place the

SCHEDULE SELECT switch to each of the re­maining positions (No. 2, No. 3 and No. 4) and
preset a different welding sequence program in
the same manner as Schedule No. 1.

Figure 4-A - Typical Time Parameter Set Up

2. Set the STRIKE open-circuit voltage require-

ment (VOLTS) by operating the INC./DEC. toggle
directly below the VOLTS digital display, and
the desired setting will appear in its window.

3. Leave the rotary selector in the STRIKE position
to set the PREFLOW and POSTFLOW Time
parameters (as shown in Fig. 4A). Actuate the
Times/A.H.-INCH toggle switch to its TIMES
(Cycle) position, and observe that the existing
numbers shown in the IPM and VOLTS windows
will change—the new parameters being the pair
of time functions in the chart(s) adjacent to the
selected condition (in this case, the pre- and
postflow data).

To reset or change these Time parameters (see
Fig. 4A); actuate and hold the TIMES toggle posi­tion, while simultaneously operating the appro­priate INC./DEC. toggle switch below each of the
time parameters being set. The preset time inter­vals will be displayed in their respective IPM and
VOLTS digital windows.

E. Reposition the rotary Condition Selector to the Start

position, and program the following:

B. Unlock the front panel door of the control cabinet to

gain access to the inside panel controls.

C. Make sure the Test-Volts toggle switch is in the

WELD position.

D. Place the rotary Condition selector to the Strike posi-

tion, and program each of the following (see Sect. II­A-6-b, -c and II-B-1,-2):

1. Set the STRIKE wire feed speed (IPM) by oper­ating the INC./DEC. toggle directly below the
IPM digitaldisplay, and the desired setting will
appear in its window.

1. Set the START wire feed speed (IPM) and arc
voltage (VOLTS) parameters using the procedures
outlined in III-D-1 and -2.

2. Leave the rotary selector in the START position to
set the START TIME and STRIKE TIME param­eters and use the procedure outline in III-D-3.

F. Reposition the rotary Condition to the Weld position,

and program the following:

1. Set the WELD wire feed speed (IPM) and arc
voltage (VOLTS) parameters using the procedures
outlines in III-D-1, and -2.

14

2. Leave the rotary selector in the WELD position to
set the WELD TIME and BURNBACK TIME
paramet-ers and use the procedures outlined in III­D-3, and also the following:

a. WELD TIME setting requirements for:

(1) Continuous Seam Welding—set time to

zero .

(2) Single Time Weld without carriage

travel (customer must deenergize the
arc detection output signal)—set time
from 1 up to 999 cycles.

(3) Single Time Weld with carriage travel

(the Arc Detector Circuit provides a
signal to initiate travel of a carriage, or
fixture)—set time from 1 up to 999 cycles.

(4) Repeat Timed Weld (same as 3) except

that the elapsed time between welds is
preset in the REPEAT TIME parameters.

b. BURNBACK TIME setting requirements:

(1) If automatic adaptive anti-stick is de-

sired—set time to zero.

(2 )If manual burnback (anti-stick) is

needed—set time required from 1 cycle
on up.

G. Reposition the rotary Condition Selector to the Crater

position, and program the following:

1. Set the CRATER wire feed speed (IPM) and arc
voltage (VOLTS) parameters using procedures
outlined in III-D-1 and -2.

2. Leave the rotary selector in the CRATER position
to set the CRATER TIME and REPEAT TIME
parameters and use the procedure outlined in III­D-3.

H. Reposition the rotary Condition Selector to the blank

position, and program the following:

1. Set the MISSWELD TIME* and RETRACT TIME
parameters using the procedures outlined in III-D-

3. *The Missweld cycle only monitors the WELD
Condition. If not desired, set Missweld Time to
zero .

I. Reposition the rotary Condition Selector to the RUN

position for the following operations:

1. This is the normal operating setting used when the
control is fully programmed and ready-for-use.

As mentioned earlier in the Note following Section
II-B-2-b, the control is preset at the factory toprovide
the optimum starting characteristic for most weling
conditions. However, due to factors such as inaccu­rate parameters (for a given wire type and size),
welding technique, shielding gas, power supply
slope and/or response, you may have to readjust
the factory-set starting characteristics to prvide
the best arc starts possible. To do this, it is neces
sary to readjust the factory-set condition to provide
a hot start characteristic in which the initial starting
voltage (open-circuit voltage) will be slightly higher
than actual welding voltage (arc voltage) and speed
which initially is somewhat lower than the selected
wire feed speed desired.

To set-up the control to provide this, do the follow
ing:

a. Program the welding condition you need in the

IPM (wire feed speed) and VOLTS (arc voltage)
windows, and fine-tune these parameters until
you have the welding arc desired - Do not at this
point concern yourself with the arc starts , this
follows.

* If the Weld Crater conditions are both Timed ; simply
preset the appropriate time desired for each condition

- .1 up to 99.9 seconds for Weld, and .1 up to 99.6
seconds for Crater.

If the Weld condition is a Continuous Seam weld,
the CRATER condition can either be Timed or
skipped completely.If Crater Fill is desired; enter

from 1 to 999 cycle in the Crater Time parameter. If
Crater Fill is not desired; simply enter zero in the
Crater Time parameter, and this sequence will
be skipped after the STOP switch terminates the
Weld condition sequence.

** Repeat Time—if repeat timed welds are not used, set

this time to zero. If repeat welds are desired, the
cycles set will control the elapsed time between the
Timed weld parameters.

b. If after the welding condition is fine-tuned you

find that the arc starts are unsatisfactory, pro­ceed as follows:

(1) During an actual weld, depress and hold the

Arc Hours/Inch Preset toggle position
and observe the numbers displayed in the
IPM and VOLTS windows.

(2) For proper starts, the number in the IPM

window should be in the range from 105 to

115. If it is not, adjust the Inc/Dec toggle
(below the IPM window) until the displayed
number reads 110.

(3) Similarly, the number in the VOLTS win-

dow should be in the range of 90 to 100.
Again, if it is not, adjust the Inc/Dec toggle
(below the VOLTS window) until the dis­played number reads 95.

15

Figure 5 - Typical Welding Conditions Sequence Per Schedule

(4) These adjustments to the control should

now provide good arc starts to a viable
welding condition.

(5) A good rule-of-thumb to follow when-

ever you set up a new welding condition
and you experience unstable starts, is to
simplycheck the start characteristic num­bers (while welding) to make sure they are
within the ranges described in the preced­ing steps.

2. Set the cold wire INCH wire feed speedandmontor
or reset (zero) the ARC HOURS by actuating Arc
Hours-Inch Preset toggle switch position, while op­erating the appropriate INC./DEC. toggle below
their respective charts. The preset cold-inch wire
feed speed, and accumulated arc hour usage will be
displayed in the appropriate IPM/VOLTS digital
windows.

IV. WELDING SEQUENCE

After the desired parameters have been weld-tested
and satisfactory results achieved, the preset condi­tion can be lock-in by securing the front panel door
to the cabinet with a lock. None of the welding
parameters can be altered once the cover is closed.

To operate the preset welding schedule do the fol­lowing (a typical welding sequence is shown in Fig.

5):

A. Pull the Power switch button out to energize the con-

trol. (For one second, the IPM and VOLTS will display
an identification program number for the MPU printed
circuit board in your control.)

B. Operate the GAS PURGE switch to purge the shield-

ing gas line of the torch.

C. Place the SCHEDULE SELECT switch to the desired

schedule No. 1, No. 2, No, 3, or No. 4.

D.Operate the cold wire UP/DOWN INCH switch to posi-

tion the wire above the workpiece.

E. You are now ready to weld in the selected schedule.

Place the Start-Stop switch in its START position, and
the control will automatically sequence thru Preflow,
Strike, Start (also initiates arc detector carriage drive
signal), and into the Weld condition programmed.

F. To stop welding, proceed as follows:

1. For continuous seamwelds, simply operate the
STOP switch (or a remotely actuated stop
button or micro switch), and all welding will
cease except Crater-Fill, Burnback, Postflow and
Retract.

2. For single "Timed" weld setup, the control will
automatically provide an orderly sequenced shut
down; however, in order to start another weld, you
must press the Stop switch (panel or remote)
and then reoperate the Start position to reinitiate
the preset sequence.

3. For repeat "Timed" weld setups, the control will
automatically continue to cycle through its preset
weld on and weld off sequence, until theDigimatic’s
Stop (or remote stop device) is operated.

4. The control can, or will, also shutdown as a result
of the following:

16

a. If preset Strike Time or Missweld Time is ex-

ceeded, and /or preset wire feed speed or arc
voltage parameters cannot be maintained,
the Digimatic will shutdown and simulta­neously indicate the cause by flashing a digital
display in the IPM or VOLTS window.

A. General

1. Check interconnection between digimatic control and

power supply. Make sure that the contactor and volt­age control switches are placed in the Remote
position.

(1) If the Strike Time parameter was exceeded,

its preset time-interval will flash in the
VOLTS WINDOW—and you may have to
preset a little more time.

(2) If the Missweld time cycles was exceeded,

its preset time will flash in the IPM window
and the unit will abort/shutdown— make
sure that all parameters accurately reflect
the welding application.

(3) If the wire feed speed (IPM) and/or arc

voltage (VOLTS) parameters cannot be
maintained in any of the welding condi­tions (Strike, Start, Weld, or Crater), the
flashing display will only signal the original
preset Strike parameter(s).

b. In order to restart an abort shutdown, simply

depress the Gas Purge/Reset rocker switch to
clear the abort, and then repress the Start rocker
switch to start a new weld.

V. TROUBLESHOOTING

Listed below are a number of trouble symptoms,
each followed by the checks or action suggested to
determine the cause. Listing of checks and/or ac­tions is in most probable order, but is not necessar­ily 100% exhaustive. In addition to the following
troubleshooting symptoms/checks, we have also
provided a Sequential Troubleshooting Flow Dia­gram (Fig. 6) which can be very useful in your
diagnosis.

Always follow this general rule: Do not replace a
printed circuit (PC) board until you have made all the
preceding checks. Always put the Power switch in
off position before removing or installing a PC
board. Take great care not to grasp or pull on com­ponents when removing a PC board. If a printed
circuit (PC) board is determined to be the problem,
check with your ESAB supplier for a trade-in on a
new PC board. Supply the distributor with the part
number of the PC board as well as the serial number
of the wire feeder. Do not attempt to repair the PC
board yourself. Warranty on a PC board will be null
and void if repaired by customer or an unauthorized
repair shop.

2. Energize the power supply and the control.

3. Immediately after the control is turned on , a number

(e.g.:3) will appear in the IPM readout window and will
only be displayed for 1-second. This number identi­fies the current program (E-Proms) used in your
control. When a Program is changed, the new E­Proms will automatically identify the new program
number being used. If a revision is made to an
existing program a __________________________
decimal number .1,.2,.3,etc. indicating the numerical
revision will also appear in the VOLTS readout win­dow simultaneously.

4. After the one (1) second delay; the preset Weld
parameters, corresponding to the position of the Con­dition selector switch, will be displayed in the IPM/
VOLTS windows. With the switch in its normal Run
position the STRIKE parameters will initially be dis­played.

5. It is also important to set the STRIKE time long enough
to provide adequate time for the current detector to
energize before the Strike timer times out. If the Strike
timer times out the unit will abort and the preset Strike
time parameters will flash in the VOLTS window.

6. If the control is not functioning properly (or as de­scribed above); for example, the numbers that ap­pear in one or both of the display windows are mean­ingless (all zeros, eights, decimals,etc.), or are com­pletely incorrect in relation to your settings, - the
memory must be cleared. This condition might occur
after a bad lightning storm, extremely bad power line
surges, etc. To clear the memory, do the following:

a. Turn off the unit’s 110-volt Power switch.

b. Using one hand, hold both of the Inc./Dec. toggle

switches in their INC position while reapplying 110­volt power with the other hand.

c. Almost immediately after the Power has beenturned

On, release the Inc./Dec. toggle switches to the
neutral (spring-return center) position and each of
the windows should display one zero, indicating a
successful reset or clearing has taken place.

7. You can now enter the desired information as des­cribed in this booklet.

17

B. No preset numbers, or meaningless numbers, ap

pear in display windows.

start switch circuit components—switch, plug,
receptacle, etc.

1. Make sure the LED Display board harness/plugis
plugged into the P5 receptacle on the MPU board.

2. Check that 110 vac is available across terminals T1-

1 and T1-3, if present;

3. Check for (+) 5 volts between terminals T1-12 and T1­10; if voltage is present, replace the MPU board. If
voltage is not present, check the voltage

regulator (VR). The voltage regulator is located
on the bottom of the control box.

4. Check the input and output voltage of the regulator VR
as follows:

The input should be approx. 11 volts, as measured
across capacitor C4 (between T1-10 and VR-1)
located on the VR socket. If voltage is not present
check the output of transformer CTR-1. It should read
10 volts AC from the center tap (Grn/Yel) to both of
the green windings taps. If CTR-1 good, but the input
to VR is still not present, check plug P3 per the
schematic diagram. If no opens or shorts are found
and input is still missing (to VR)—replace I/O
board. If input to VR is present, but output is missing—
replace VR. If numbers still do not appear in win­dows—replace I/O and/or MPU boards.

5. If all microprocessor memory is lost, it may be due to
low (sagging) line voltage or excessive line voltage
drops. This may occur if auxiliary equipment (such as
carriage drives(s), drill motor, hot plates, etc.) also
derive their 115- volt power from the same power
supply as the Digimatic control. Do NOT connect
auxiliary equipment to the 115-volt duplex receptacle
on the power supply. If problem still exists, call for
factory assistance.

C. Motor does not run.

1. Check to make sure all required (and/or optional)

accessories are correctly assembled as described in
Section I.

2. Make sure that plug P2 is securely connected to
receptacle P2 on the I/O Board, and then release the
clapper arm (pressure roll) on the Accessory Support
Assembly.

c. If motor will not turn using either of the above

switches, replace the J governor board. If motor
still refuses to run, replace the I/O and MPU
boards respectively.

D. Motor runs, but not at right speed.

1. Check tachometer assembly mounted on the end of

EH-10 wire feed motor.

2. Make sure the tach disc is securely fastened to the
motor shaft and that the strobe markings are not
scratched. Check that the disc is properly centered in
the strobe pickup on the p.c. board.

3. If all items in step 2 are in order, and motor speed is
still incorrect, replaced MPU board.

E. Arc VOLTS display reads zero after TS is oper­ated.

1. Check that the 5-pin plug is securely connected to the

P3 receptacle on the MPU board.

2. If no reading is displayed, check for arc voltage feed­back between terminals T1-18 and T1-19 (test points
TP1 and TP2, respectively, on I/O board). This volt­age signal should correspond to that shown on the
power supply voltmeter.

3. If voltage still reads zero, but power supply indicates
a potential, trace the voltage pickup wiring from
the power supply to digimatic. If wiring is correct
and problem persist, proceed to step 4.

4. Disconnect the P3 plug from its MPU board socket
and, using a meter check for +/-12 volt power supply
output between plug pins P3-1 and P3-2 (for +12 v.),
and between plug pins P3-4 and P3-2 (for -12 v.)
respectively. If voltage is present, replace the MPU
board.

F. Control Shut Down - either present VOLTS or IPM

displays will flash. The control will flash thparam­eter, VOLTS or IPM, that cannot be maintained.

If this condition occurs, the respective servos need
to be checked and, if necessary, readjusted as follows:

a. Operate the Start Switch (arc voltage of 10 volts

ormore must be present) and the motor shaft/feed
roll should turn. If motor doesn’t run, release start
switch and;

b. Operate the INCH switch. If the motor inches , but

will not operate from the start switch, check the

Please note that the servo checking/setting procedure
for the Digimatic II control contained herein is different
from all previous Digimatic controls. Therefore, you
need not adjust the voltage servo trimpot or speed
servo trimpot on the I/O p.c. board - these trimpots are
factory-set and sealed, and should never be adjusted
(as was required of older Digimatics).

18

1. This symptom can occur as a result of the either or all
of the following; the Speed and Voltage servo adjust­ments are incorrect and the conditions "set " may not
be maintainable. To check and, if necessary, readjust
the servos - proceed as follows.

NOTE: Prior to checking the servos, make sure the

control is connected to a suitable ESAB power
supply in order to obtain the necessary
o.c.v.(open circuit voltage); otherwise, the mo­tor will not run.

2. The Speed and Voltage servos in this control are
simultaneously checked and displayed by depressing
and holding the Arc Hrs./Inch Preset switch (on inside
panel) in its "down" position during an actual weld and
the wire feed motor running. The speed servo number
is displayed in the left (IPM) window and should be
about 110, and the right (VOLTS) window will display
the voltage servo number. This number will between
90 and 100* for the actual welding condition.

* Voltage servo setting below 95 will normally provide

hot arc starts; whereas, setting over 100 will not.

3. If a Speed abort had occurred (IPM window flashing),
check and/or adjust the speed servo as follows:

Open the pressure roll clapper (so as not to feed wire),
toggle-down the Arc Hrs/Inch Preset switch position,
and either place the weld Start/Stop switch in START
position or toggle down the INCH switch. Check the
number in the IPM window - it may appear unsteady
but readable and should be about 110.

If the speed servo cannot be adjusted at all, the
problem may be in the J-Governor, and/or I/O, and/or
MPU p.c. boards which must be replaced as required.

4. If a Voltage abort had occurred (VOLTS window flash­ing), check and/or adjust the voltage servo as follows:

This is a two-man operation. Set a welding condition
which closely corresponds to your welding application
and the proper speed (ipm) for a given wire size, and
then place the Weld switch in Start position and strike
a welding arc. While welding, toggle-down the Arc
Hrs./Inch Preset switch position and read the
number displayed in the VOLTS window, it may
appear unsteady but readable and should be 95.

If the number is not in the 90-100 range, use the Inc./
Dec toggle (below the VOLTS window) to adjust the
number to 95 - while holding the toggle position
mentioned above and while welding.

5. If the voltage servo cannot be adjusted, check
for proper operation of the power supply as follows:

a. Set the Digimatic voltage display to zero (thissetting

will override the servo).

b. Place the Panel/Remote switch on the power sup-

ply in PANEL position.

c. Make a weld by controlling the arc voltage directly

from the power supply potentiometer. If a weld can
be made with good control over powers connecting
voltage control cable, or in the Digimatic control.

If it is higher or lower, use the Inc/Dec toggle (below
the IPM window) to adjust the number to 110 - while
"holding" the A.H.\Inch Preset as mentioned above
and while the wire feed motor is running.

e. Check the control wires in the interconnecting volt-

age control cable for continuity between the appro­priate terminals in the power supply and Digimatic
using the schematic diagrams.

f. If continuity is correct, replace the I/O board and/or

the MPU board.

19

IMPORTANT: In addition to the Welding Condition Sequence Diagram (Figure 5) and the Trouble Symptom/checks described
in Section V, the Sequential Troubleshooting Flow Diagram (Figure 6) can be very useful in diagnosing your problem.

Before using the Flow Diagram, make sure the Digimatic Control is connected to a suitable ESAB power supply designed for
electronically controlled arc voltage regulation (see Section 1-A-4). The power supply muct be setup for "remote" operation, and
the control preset and energized to provide the desired welding condition parameters.

If you wish to troubleshoot the Digimatic Control without using a power supply, two TEST toggle switches labeled "Amps" and
"Volts", on the inside control panel provide a convenient way to "test-sequence" all of the welding condition parameters without
actually striking an arc. To do this, the control must be connected to an external 120 VAC power source (by customer),

preset all "arc voltage" condition parameters to zero (0) cycles, and preset the "Strike-Time" parameter to at least 150
cycles. The extended strike-time period is necessary to allow enough time to manually simulate an arc detection signal by

momentarily actuating the "Amp" toggle TEST position. Now, place the "Volts" toggle to its TEST position, and release the clapper
on the accessory support to remove wire feed pressure. With this accomplished, follow the Flow Diagram instruction sequence
until the weld condition is into the Strike-Time sequence. During this time period you must actuate the "Amps-Test" toggle (to
simulate arc detection), otherwise the strike-time will time out and the control will abort as shown in the diagram. If done correctly,
the unit will automatically continue through the remaining welding sequences.

20

Figure 6 - Sequential Troubleshooting Flow

Diagram

VI. REPLACEMENT PARTS DATA

1. All replacement parts are keyed on the illustrations which follow. Order replacement parts by part number and part
name, as shown on illustrations. DO NOT ORDER BY PART NUMBER ALONE.

2. Always state the series or serial number of the machine on which the parts are to be used. The serial number is
stamped on the unit nameplate.

CABINET LOCK - 950416

(J1) 19-PIN RECPT. - 950762

(C20) CAPACITOR - 950265
(SW4/PRS)
ROCKER
SW. - 950295

(J3) 8-SOCKET RECPT. - 647233

(CB) CIRCUIT
BKR. - 950874

(MLS)

OPERATOR - 950915

CONTACT - 950916

BUTTON - 950917

(SW1/SSS)
ROCKER
SW. - 2062270

(SW5/UDIS)
ROCKER
SW. - 2062363

(SSW)4-POS. ROTARY

SW.- 678915

KNOB - 950282

(D3, D4) DIODE - 995464

(on SSW)

(J4) 6-SOCKET RECPT. - 993952

(J5)3-PIN RECPT. 598397

(J2) 5-SOCKET
RECPT. - 996514

(VR) VOLTAGE REGULATOR - 950159
TRANSISTOR SOCKET - 950158
(C4) CAPACITOR - 995544

Figure 7 - Digimatic II Control Assembly, P/N 31551

21

OPT, DIGITAL D,C, AMMETER
KIT - 679111
(See L14-220)

(MSS) 6-POS. ROTARY SW. - 679914
KNOB - 950282
WASHER - 950291

DISPLAY P/C BD. ASSY. - 675269

(SW 10/A TST)
(SW8/AH)
(SW7/SID)
(SW6/VID)

(SW9/V TST) TOGGLE SW. - 950229

TOGGLE SWS. ­950087

}

(R1) RESISTOR -17240003

(REVRLY) REV. RELAY - 951089

(BR) BRDIGE - 635152

(CTR3) CONTROL
TRANSFORMER ­994303

Figure 8 - Digimatic II - Inside Control Panel

(T1) TERMINAL BOARD - 995103

(I/O) INPUT/OUTPPUT P.C. BD.
ASSY. - 674956

(MPU) MICROPROCESSOR
P.C. BD. ASSY. - 18139

J-GOV. P.C. BD. ASSY. - 994236

CURR. DETECT. P.C. BD.
ASSY. - 675280

(2) P.C. BD. RECEPTACLES ­636608

(FNI) FILTER NETWORK - 996918
Includes:
(C1, C2) CAPACITOR - 672348
(C3) CAPACITOR -993716
TIE POINT - 94W84

(CTR 1 & 2) CONTROL
TRANSFORMER ASSY. - 30684

(FB) FILTER BOARD ASSY. - 31421

Figure 9 - Digimatic II - Inner Cabinet Components

22

Figure 10 - Optional Plumbing Box - P/N 677261 (Front, Rear and Inside View)

23

Figure 11 - Schematic Diagram

24

25

Figure 12 - Wiring Diagram, Sht. 1 of 2

26

Figure 13 - Wiring Diagram, Sht. 2 of 2

27

ESAB Welding & Cutting Products, Florence, SC Welding Equipment

COMMUNICATION GUIDE - CUSTOMER SERVICES

A. CUSTOMER SERVICE QUESTIONS:

Order Entry Product Availability Pricing Delivery
Order Changes Saleable Goods Returns Shipping Information

Telephone: [phone] / Fax: [phone]

Telephone: [phone] / Fax: [phone]

Telephone: [phone]/ Fax: [phone]

B. ENGINEERING SERVICE: Telephone: [phone] / Fax : [phone]

Welding Equipment Troubleshooting Hours: 7:30 AM to 5:00 PM EST
Warranty Returns Authorized Repair Stations

C. TECHNICAL SERVICE: Telephone: (800) ESAB-123/ Fax: [phone]

Part Numbers Technical Applications Hours: 8:00 AM to 5:00 PM EST
Performance Features Technical Specifications Equipment Recommendations

D. LITERATURE REQUESTS: Telephone: [phone] / Fax: [phone]

E. WELDING EQUIPMENT REPAIRS: Telephone: [phone] / Fax: [phone]

Repair Estimates Repair Status Hours: 7:30 AM to 3:30 PM EST

F. WELDING EQUIPMENT TRAINING:

Telephone: [phone] / Fax: [phone]
Training School Information and Registrations Hours: 7:30 AM to 4:00 PM EST

G. WELDING PROCESS ASSISTANCE:

Telephone: (800) ESAB-123 / Fax: [phone] Hours: 7:30 AM to 4:00 PM EST

H. TECHNICAL ASST. CONSUMABLES:

Telephone : [phone] Hours: 7:30 AM to 5:00 PM EST

Eastern Distribution Center

Central Distribution Center

Western Distribution Center

Hours: 7:30 AM to 4:00 PM EST

IF YOU DO NOT KNOW WHOM TO CALL

Telephone: (800) ESAB-123/ Fax: [phone]/ Web:http://www.esab.com

F-15-070 92-0801 1/92 1M Printed in the U.S.A.

Hours: 7:30 AM to 5:00 PM EST