owner`s - Miller Welding

April 1979 FORM: OM-1025
Effective With Style No. HK-18
MODEL
GA-20C
OVWNER'S
MANUAL
MILLER ELECTRIC MFG. CO.
718 $. BOUNDS ST. P.O. Box 1079
APPLETON, Wi 54912 USA
NWSA CODE NO. 4579
PRINTED IN U.S.A,
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LIMITED WARRANT
EFFECTIVE: JANUARY 1, 1979
This warranty supersedes all previous MILLER warranties and is ex-
clusive with no other guarantees or warranties expressed or implied.
LIMITED WARRANTY —Subject to the terms and conditions
hereof, Miller Electric Mfg. Co., Appleton, Wisconsin warrants to
its Distributor/Dealer that all new and unused Equipment furnished
by Miller is free from defect in workmanship and material as of the
time and place of delivery by Miller, No warranty is made by Miller
with respect to engines, trade accessories or other items manu-
factured by others. Such engines, trade accessories and other
items are sold subject to the warranties of their respective manu-
facturers, if any. At the present time, the manufacturer's warranty on
the Mag-Diesel engine on DEL-200 is limited to six months and on
all other engines to one year.
Except as specified below, Miller's warranty does not apply to
components having normal useful life of less than one (1) year, such
as spot welder tips, relay and contactor points, MILLERMATIC parts
that come in contact with the welding wire including nozzles and
nozzle insulators where failure does not result from defect in
workmanship or material.
Miller shall be required to honor warranty claims on warranted
Equipment in the event of failure resulting from a defect within the
following periods from the date of delivery of Equipment to the
original user:
1. Arc welders, power sources and components . 1 year
2. Original main power rectifiers. . . 1... 224244 3 years
(labor - 1 year only)
3. All welding guns and feeder/guns , . . . ...... 90 days
4. All other Millermatic Feeders . . . . . . . . . . .. | year
5. Replacement or repair parts, exclusive oflabor . - . 60 days
6. Batteries . . 1 2 1212 1 44 4 1 4 4 446 . . 6 months
provided that Miller is notified in writing within thirty (30) days of
the date of such failure.
As a matter of general policy only, Miller may honor claims
submitted by the original user within the foregoing periods,
In the case of Miller's breach of warranty or any other duty
with respect to the quality of any goods, the exclusive remedies
therefor shall be, at Miller's option, (1) repair or (2) replacement or,
where authorized in writing by Miller in appropriate cases, (3) the
reasonable cost of repair or replacement at an authorized Miller ser-
vice station or (4) payment of or credit for the purchase price (less
reasonable depreciation based upon actual use) upon return of the
goods at Customers risk and expense. Upon receipt of notice of
apparent defect or failure, Miller shall instruct the claimant on the
warranty claim procedures to be followed, |
ANY EXPRESS WARRANTY NOT PROVIDED HEREIN AND
ANY IMPLIED WARRANTY, GUARANTY OR REPRESENTA-
TION AS TO PERFORMANCE, AND ANY REMEDY FOR
BREACH OF CONTRACT WHICH, BUT FOR THIS PROVISION,
MIGHT ARISE BY IMPLICATION, OPERATION OF LAW, CUS-
TOM OF TRADE OR COURSE OF DEALING, INCLUDING ANY
IMPLIED WARRANTY OF MERCHANTABILITY OR OF FITNESS
FOR PARTICULAR PURPOSE, WITH RESPECT TO ANY AND
ALL EQUIPMENT FURNISHED BY MILLER IS EXCLUDED
AND DISCLAIMED BY MILLER.
EXCEPT AS EXPRESSLY PROVIDED BY MILLER IN WRIT-
ING, MILLER PRODUCTS ARE INTENDED FOR ULTIMATE
PURCHASE BY COMMERCIAL/INDUSTRIAL USERS AND FOR
OPERATION BY PERSONS TRAINED AND EXPERIENCED IN
THE USE AND MAINTENANCE OF WELDING EQUIPMENT AND
NOT FOR CONSUMERS OR CONSUMER USE. MILLER” WAR-
RANTIES DO NOT EXTEND TO, AND NO RESELLER IS
AUTHORIZED TO EXTEND MILLER'S WARRANTIES TO,
ANY CONSUMER.
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ERRATA SHEET
After this manual was printed, refinements in equipment design occurred. This sheet lists exceptions to data appearing later in
this manual.
Item Part No. Listed Replaced With
No. In Parts List Part No, Deseription Quantity
39 034 857 049 857 TUBE, head 609 .... iii KR RK KEG 1
BE SURE TO PROVIDE MODEL AND SERIAL NUMBERS WHEN ORDERING REPLACEMENT PARTS,
OM-1025 Page A
1-1.
1-2.
1-3.
SECTION 1 - INTRODUCTION
Cable
Ampere Rating And Approx. Weight
100% Duty Cycie Wire Hose | Cooling In Pounds
derp Diameter Length | Method | Net | Shipping
200 Amperes 030” Through 10° Air 7 8
With CO, 045” Hard 15 Air 10 11
Figure 1-1. Specifications
1-4. SAFETY
GENERAL
This manual has been prepared especially for use in familiar-
izing personnel with the design, installation, operation, main-
tenance, and troubleshooting of this equipment. All informa-
tion presented herein should be given careful consideration to
assure optimum performance of this equipment.
RECEIVING-HANDLING
‘Prior to installing this equipment, clean ali packing material
from around the unit and carefully inspect for any damage
that may have occurred during shipment. Any claims for loss
or damage that may have occurred in transit must be filed by
the purchaser with the carrier. A copy of the bill of lading
and freight bill will be furnished by the carrier on request if
occasion to file claim arises.
When requesting information concerning this equipment, jt is
essential that Model Description and/or Stock Number and
Serial {or Style) Numbers of the equipment be supplied.
DESCRIPTION
This gun is designed specifically for the Gas Metal-Arc
Welding (GMAW) process. It is aircooled and rated at
200 amperes dcrp at 100 percent duty cycle using CO9
shielding gas. The gun is shipped from the factory as-
sembled and ready for operation with the specific wire
size components ordered. Only minor changes of parts in
the gun and wire control/feeder are necessary to convert
to 0.030 and 0.035 or 0.045 inch diameter hard wire.
The short circuiting transfer mode of Gas Metal-Arc Weld-
ing is a consumable electrode welding process in which
the electrode, the arc, and the weld puddle are contained
in a protective atmosphere of shielding gas. Consumable
welding wire is automatically and continuously fed into
the arc. High current densities permit the use of the high
welding speeds; gas shielding prevents atmospheric con-
taminations, thus eliminating the need for fluxes that
would result in slag removal.
2-1.
CAUTION |
Prior to installing the gun, ensure that the welding.
power source is completely shut down. If the con-
trol/feeder obtains its power from another source,
ensure that the control/feeder is disconnected from
| its power supply. J
GUN/FEEDER CONNECTOR INSTALLATION
(Figure 4-1)
The outlet guide is provided as part of the gun
| assembly. |
1. Loosen the gun/feeder connector securing knob on the
wire drive assembly. (For location of wire drive as-
sembly, refer to the Owner's Manual for the appro-
priate wire feeder.)
INSTALLATION
2-3.
Before the equipment is put into operation, the safety sec-
tion at the front of the welding power source or welding
generator manual should be read completely. This will help
avoid possible injury due to misuse or improper welding
applications.
The following definitions apply to CAUTION, IMPORTANT,
and NOTE blocks found throughout this manual:
CAUTION Е \
à rer
Under this heading, installation, operating, and main-
tenance procedures or practices will be found that if
not carefully followed may create a hazard to per-
| sonnel. |
IMPORTANT
Under this heading, installation, operating, and main-
tenance procedures or practices will be found that if
not carefully followed may result in damage to equip-
i ment. i
“NOTE
Under this heading, explanatory statements will be
found that need special emphasis to obtain the most
efficient operation of the equipment.
.
IMPORTANT
The outlet guide should be positioned as close as
possible to the drive rolls without touching them,
This gives the wire maximum column strength thus
I eliminating waves, 1
2. Insert the gun/feeder connector, which includes the
installed outlet guide, into the wire drive assembly
opposite the inlet wire guide.
3. Tighten the gun/feeder connector securing knob.
GUN SWITCH CONNECTION (Figure 4-1)
Align the key on the gun switch connector with the
keyway on the Switch Control receptacle; insert the con-
nector and rotate clockwise.
REPOSITIONING GUN SWITCH (Figure 4-1)
The gun is shipped with the gun switch positioned as
illustrated in Figure 4-1. The gun switch can be repos-
itioned on top of the gun handle by following the pro-
cedure outlined in Steps 1-7 below.
OM-1025 Page 1
3-1.
Page 2
1. Remove head tube securing screw {7) in gun handle.
2. Remove pin (5) and locking ring (8) holding handle
halves together.
3. Separate two halves of gun handle.
4. Rotate head tube (4) 180°. Ensure that machined
depression in head tube (4) is lined up with hole for
head tube securing screw (7).
GAS METAL-ARC WELDING (GMAW)
1. Ensure that proper electrical connections have been
made to the welding power source, and the controi/
feeder if applicable {refer to the respective Owner's
Manuals).
2. Ensure that the proper shielding gas is connected to
the shielding gas valve.
3. Ensure that the welding wire has been properly
threaded and that correct initial tensions have been
set on the drive rolls {refer to the appropriate
Owner's Manual}.
4, Turn on the shielding gas supply.
5. Place the wire feed control{s) in the required posi-
tion for the welding set up.
6, Place the controls on the welding power source in
the required position for the welding set up (refer
to welding power source Owner's Manual).
7. Energize the welding power source, and the
control/feeder {refer to the respective Owner's
Manuals).
CAUTION |
vom.
If the welding power source is energized and the
switch lever on the gun is depressed, open-circuit
voltage will be present on the welding wire and
| any metal part making contact with it. |
When installing new equipment, or after prolonged
shutdown, allow shielding gas to flow continuously
for at least one minute prior to welding in order
to purge the shielding gas line. Place the Wire
Speed control to the minimum setting to avoid
| wasting the welding wire while purging. ;
8. Press the Purge button {if applicable) or the switch
lever on the gun handle to purge the gas line,
O, Actuate the switch on the gun handle to run the
wire out beyond the end of the gas nozzle (if
applicable). Cut the wire off approximately 1/4” to
3/8” from the nozzle.
10. Set the Wire Speed control slightly in excess of
anticipated wire speed.
IMPORTANT
It is better to have the wire speed rate too fast
than too slow, If the wire feed rate is too slow
upon initial welding, the wire may burn back into
I the contact tube, thus damaging it. I
IMPORTANT
Ensure that the switch leads do not become twist-
I ed when the head tube is rotated. | N
5. Join handle halves together and rotate locking ring.
6. Insert pin (5) through handle halves and switch lever.
7. Replace head tube securing screw (7) and tighten.
SECTION 3- SEQUENCE OF OPERATION wesc
CAUTION |
Prior to welding, it is imperative that proper pro-
tective clothing (welding coat and gloves) and eye
protection (glasses and/or welding helmet) be put
on. Failure to comply may result in serious or
permanent bodily damage.
CAUTION
The welding wire and all metal parts in contact
with it are energized while welding. Do not touch
the welding wire or any metal part making contact
with it.
11. Hold the end of the gas nozzle approximately 1/2"
from the workpiece.
12, Press the switch lever on the gun handle. Gas will
start to flow, wire will start to feed and the arc
will be established. If wire slippage is noticed,
tighten drive roll pressure adjustment 1/4 turn at a
time until slippage stops. Do not overtighten.
Ensure that the welding power source is completely
shut down and that power is removed from the.
feeder/control prior to performing drive roll pres-
sure adjustment.
13. After the controls on the welding power source,
and the control/feeder (if applicable) have been
adjusted for normal operation, welding power
source (and the contrôl/feeder) will function auto-
matically whenever the gun switch is depressed.
Releasing the gun switch lever will extinguish the
arc and cause wire feed and gas flow to stop.
3:2. SHUTTING DOWN
1. Turn off the shielding gas at the source.
CAUTION: |
If welding is performed in a confined area, failure |
to turn off the shielding gas supply could result in
a build-up of gas fumes, thereby endangering per-
i sonnel re-entering the welding area. j
2. Deenergize the welding power source, and the control/
feeder.
UTE |
Ensure that the welding power source is completely
shut down and that power is removed from the
feeder/control (if applicable) prior to attempting
maintenance work on this gun or associated equip-
4-1. INSPECTION AND UPKEEP
Usage and shop conditions will determine frequency and
type of maintenance required.
1. Inspect gun for broken areas, cracks and loose parts;
tighten, repair and replace as required.
2. Carefully remove any weld spatter or foreign matter
which may accumulate around the nozzle orifice,
3, Remove any accumulation around the switch,
4. Repair or replace as required all hose and cabling; give
particular attention to frayed and cracked insulation
and areas where it enters equipment.
5. Remove grease and grime from components; moisture
from electrical parts and cables.
6. Blow out the casing with compressed air when chang-
ing wire. This removes any metal chips and dirt that
may have accumulated.
4-2. CONTACT TUBE REPLACEMENT (Figure 4-1)
1, Remove the nozzle (1).
1
EA
aN
Gun Switch
Gun Switch Monocoil Liner 9
Connactor |
1
\
12
Gun/Feeder Connector
TC-048 002
Figure 4-1. Gun Components
SECTION 4 - MAINTENANCE ===
2. Cut off any portion of the electrode wire which ex-
tends beyond the end of the contact tube,
3. Remove the contact tube (2) and replace with appro-
priate contact tube,
4. Replace the nozzle (1) and resume operation.
4-3. CHANGING WIRE SIZES (Figure 4-1)
Ensure that the welding power source is completely
shut down and that power is removed from the
control/feeder {if applicable) prior to changing the
т wire, control/feeder components, or gun components. y
Whenever the electrode wire size is changed, blow *
out both the monocoil liner and monocoil casing
with compressed air.
In changing the gun from .030” to .035” wire {or vice
versa} it is only necessary to change the contact tube.
When changing from .030" or .035” to .045” wire lor
vice versa) the monocoil liner, contact tube, and wire
guides must be changed. (For inlet wire guide installation,
refer to the appropriate welding power source or control/
feeder Owner's Manual.)
1, Remove the nozzie (1).
2, Cut off any portion of the electrode wire which
extends beyond the end of the contact tube.
3. Remove the contact tube (2).
4, If only the contact tube requires changing proceed
to Step 17.
5, Retract the remaining electrode wire onto the wire
spool.
6, Remove the contact tube adapter (3) from the
head tube (4).
7, Disconnect the gun assembly from the control/
feeder.
8. Remove the outlet wire guide (9) from the gun/
feeder connector,
9. Loosen the monocoil liner set screw (6) in the gun
handle. —
10, Pull out and remove the monocoil liner from the
gun/feeder connector end of the gun assembly.
11. Loosen the set screw (9) holding the bushing (11)
to the monocoil liner and remove the bushing (11)
and o-ring (12).
12. Slide the o-ring {12) and bushing (11) on the new
monocoil liner as illustrated in Figure 4-1 and
tighten the bushing set screw (9).
13. Lay the gun out flat (no coils in the cable/
conduit).
14. Insert the new moncocoil liner from the gun/feeder
connector end of the gun assembly. Ensure that
the liner is seated against the rear of the contact
tube.
15. Install the rear outlet wire guide (10).
OM-1025 Page 3
Page 4
The new monocoil liner will be longer than neces-
sary. Cut off the excess liner 1/4” beyond the
| head tube. Deburr the liner if necessary. i
16. Install the contact tube adapter (3) into the head
tube (4) and tighten the monocoil liner set screw
(6) in the gun handle to lock the liner in place.
Do not overtighten.
17. Install the new contact tube (2).
18. Replace the nozzle (1}.
19. Make gun connections, if applicable, as instructed
in Sections 2-1 and 2-2.
20. Thread new size electrode wire,
If the welding power source i$ energized and the
switch lever on the gun is depressed, open-circuit
voltage will be present on the welding wire and
[ any metal part making contact with it, J
21. Resume operation.
April 1979 FORM: OM-1025
| Effective With Style No. HK-18
MODEL
GA-20C
39
Hi
21 27 28 29 22
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Go,
25
Includes
23 N 30 Items 27, 28 & 29,
26
32 31
TC-049 927
Figure A — Exploded View Of GA-20C Gun
OM-1025 Page 1
Quantity
Model
8MM | 9MM | 1.2MM
Item Factory | ‚031 | .035 047
No. Part No. Description .030” [ .035” | .045”
Figure A Exploded View Of GA-20C Gun
1 049100 NOZZLE, screw type 0.620 orifice 2-1/16 long .. 1.122220 14 0044 400 aa 11000 1 1
2 000067 TUBE, contact .030 & 035 wire ... 1.222012 2 4004 40 14 a a 14 4 ae 0e a 4 aa an 6 1
2 000068 TUBE, contact .030 & ‚035 Wire oti iii et ie titrate nanan i 1
2 000069 TUBE, contact 04 Wire oi ii iii i ii tees artes ines 1
3 049309 ADAPTER, tube - contact .......... cine enens eee 1 1 1
4 6049853 ADAPTER W/RINGS, nozzle oti tit ttt te eet ata a 4 ea aa 40 1 1 1
5 082063 NUT, locking - conduit 7/8-20 111111204014 4 4 4 4 4 4 44 4 4 4 a 4 4 4 a ua a a aa 000 1 1 1
6 081957 SWITCH, leaf ....... cities ee ere ee 1 1 1
7 601869 NUT, steel - hex jam B/16-18 1.111202 4 144 4 4 4 i teense eevee 1 1 1
8 1049737 SCREW, set - steel socket hd 5/16-18 ..............,. 0... e arar. 1 1 1
9 049321 HANDLE, gun - Bottom Li ii i ee eee ee ae ae 1 1 1
10 059294 SPRING, compression 0.210 OD x 5/8 long . .. iii iii, 1 i 1
11 6049313 TRIGGER, QUN LL. oo i ct tt eet ee teas cer anaes 1 1 1
12 077650 TUBING, vinylgINo.7x3/4 ............. ee ee eae 1 1 1
13 049872 CORD, power (consisting of) 1.020200 44 44 44 48 46 4e 4 4 a 44 4 ee 4 ee 040 1 1 1
14 079878 . HOUSING, plug - plastic {consisting of) .............0... ara. 1 1 1
15 079535 ., TERMINAL, male 1 pin oon i ee ee er tee ce era 2 2 2
16 079531 .CLAMP, cable 29/64............ ....edersrierredca:recorerendoroaora rn 1 1 1
17 604525 .CORD, portable No. 18 2/C (order by ft) .............._0.0000 0000 e A 2ft. 2ft. 2ft
18 081909 SPLICE, parallel 20-16 wire 1.111010 2 1114 44 4 24 44 4 4 4 4 8 4 4 4 44 nadaa da 2 2 2
19 049319 STRAIN RELIEF, bottom - cable... 1.022000 00 1 4 0 4 4 4 4 4 4 a 4 a 0 ea da an 0 ee 1 1 1
20 049874 CONNECTOR, cable - feeder end .. 1.111112 4 11 Va 44 4 4 2 4 a 4 4e ea 44 a a a a 4 0 i 1 1
21 079974 O-RING, 1/21Dx 0.103 11200 44 4 44 8 4 4 88 44 44 4 A 4 A 4 4 4 4 8 0e ae aa 0e 0 2 2 2
22 049310 GUIDE, wire - outlet 030-035 wire 1... 1110202 24 04 4 4 44 4 44 8 4 4 KR KM 1 1
22 049311 GUIDE, wire - outlet 045 wire 1.211204 4 44 4 4 4 4 0 14 4 8 4 4 4 44 benny anna 1
23 049312 RING, locking-handie ....12200 20000004 4 4e 44 A 44 ie ee er eae 3 3 3
24 049876 NUT, connecting - cable .. 1.112240 0 004 44 4 44 a 4e a 4 4 a 4 a a 4 ea a ea ae 0 ee 2 2 2
25 049318 STRAIN RELIEF, top - cable .. 1.210400 0 04 44 14 4 24 a 8 4 4 ea 4 a a 4 a a a a a da eau» 1 1 1
26 049302 LINER, monocoil .030 - .035 wire x 10 ft or {consistingof) ................ 1 1
26 049300 LINER, monocoil .030 -.03b wire x 15 ft {consistingof) ................... 1 1
26 049304 LINER, monocoil .045 wire x 10 ft or (consisting of) ..................... 1
26 049306 LINER, monocoil .045 wire x 15 ft (consisting of). ........... eee... e... 1
27 079975 .O-RING, 3/16 1D x 0.103 ...... RR RR RR е, 1 1 1
28 049307 .COLLAR, locking- liner «vrei ie te eee tr et ei teens 1 1 1
29 081959 . SCREW, set - steel 6-32 x 3/32 11111224 1 44 44 4 8 4 4 4 8 4e 0 4 à a 4e a a da na ae = i i 1
30 049301 .LiNER, monocoil .030 - 035 wire x 10 ftor ......................... > 1 1
30 049299 .LINER, monocoil ,030 -.035 wire x 15 ft ........ e. KK 1 1
30 049303 . LINER, monocoil .045 wire x 10 ftor .. 1.121041 0 04 44 44 44 4 8 ea 4 8 aa a au 0 1
30 049305 .LINER, monocoil .045 wire x 15ft ........ e... . . . 4 0 ie ieee ean 1
31 049298 STRAIN RELIEF, extension - cable ............... e. e,0;0r0rr ree. 2 2 2
32 049317 CABLE/CONDUIT, 1Oftor "1111000 4 Lea aa aa a LL LE a ea a an à 1 1 1
32 049316 CABLE/CONDUIT, 15ft ....... e... ite eee eet eee ee eee a ane 1 1 1
33 049320 HANDLE, gun = 10D tv tet et eee ee ee ee ee 1 1 1
34 059293 RIVET, steel - solid flared hd 7/32 dia x 1-1/4 long ........... .ee..xarada. 1 1 1
35 1602173 SCREW, set - steel socket hd 10-32 x 1/4 .......... ....e.0. 0 re r0a0ocro 1 1 1
36 049871 STRIP, paper 0.20 x 7/8 X 1... ii ii te eee nk 1 1 1
37 0498/5 CONNECTOR, cable -gunend ....14.2204 04 0 4 144 44 44 1 4 da A4 A 4 a aa ea 40 1 1 i
38 049854 TUBING, glass - acrylic 1/2 x 4-1/4 i eee ee eee i 1 1
39 034857 TUBE, head B00 .030- 035 Wire or .............. ee eee eee eines 1 1
39 6049858 TUBE, head 809 ‚030 - 035 wire ........... ieee een 1 1
39 049857 TUBE, head 609.045 wireor ,........... . .s0r0dorarecerecacerdoaoo | 1
39 049858 TUBE, head 800 040 Wire .. ove tee ee ee ee na ae 1
BE SURE TO PROVIDE MODEL NUMBER WHEN ORDERING REPLACEMENT PARTS.
OM-1025 Page 2
Parts For Optional Equipment
Factory | |
Part No. Description | Quantity
049 098 NOZZLE, screw type 0.370 orifice x 2-3/32 LL 111211444044 4 ier ii i ee aaa
049099 NOZZLE, screw type 0.370 x 2-3/32 1.110210 i ir et ee eee
058 369 NOZZLE, slip type 0.620 ID x 2-1/16 .....1202202 010410 104 4e aa 4 ea ee ee ee ee a eee ea ee aa 4 6
049 101 NOZZLE, slip type 0.370 orifice x 2-3/32 112412 04444 44 4 44 44 ee eee ite eee
049 102 NOZZLE, slip type 0.495 orifice x 2-3/32 1.111104 REKEN aaa
058 375 NOZZLE, spot 0.746 ID x 2-3/8 oi i i tte i se ie ea
058 372 NOZZLE, spot-insidecorner 0.740 ID x 2-3/8... ii ee ieee 06
058 374 NOZZLE, spot- outside corner 0.745 ID x 2-3/4 iii ieee aaa
049929 NOZZLE, screw type 0.620 orifice x 2-1/16 ‚000000000000 0 iii 6 AA a 6 eu»
049930 NOZZLE, slip type 0.620 orifice x 2-1/16 ...........—recexecir:ecaneerrearere raredarereo,
md ==> — —. — o o o E]
BE SURE TO PROVIDE MODEL NUMBERS WHEN ORDERING REPLACEMENT PARTS,
Page 3