Miller Electric ST-800 202-A User manual

OWNER’S MANUAL
©1997 MILLER Electric Mfg. Co.
April 1997 FORM: OM-817A
Effective With Serial No. KG102608
Process Selector Control
1. Specifications
Process Selector Control For SMAW, GTAW, GMAW, And FCAW Welding Processes
Rated At 100 Volts, 650 Amperes At 30% Duty Cycle
Electrically Isolates Weld Current At Electrodes
Allows Changing Process Without Changing Cable Connections
ST-800 202-A
2. Safety Symbol Definitions
Warning! Watch Out! There are possible hazards as
shown in the adjoining symbols. Beware of electric shock from welding electrode or wiring. Touching the electrode while in contact with the work or
ground can cause electric shock. Always wear dry
gloves. Keep all panels and covers closed.
Beware of electric shock from wiring. Keep all panels and
covers closed. Welding processes cause flying pieces of metal and slag. Wear safety glasses with side shields.
Have only trained and qualified persons install, operate,
or service this unit. Call your distributor if you do not un-
derstand the directions. For WELDING SAFETY and
EMF information, read wire feeder and welding power
source manuals.
Hot parts can cause burns. Welding makes parts very hot
−
let them cool before touching.
3. Location And Mounting
1 Welding Power Source
2 Process Selector Control
Place control as shown.
3 Brackets (Optional)
4 Intellitig Unit
Use brackets as shown when at-
taching control to a D-60 model wire
feeder or Intellitig unit.
Tools Needed:
1
2
2
3
4
ST-800 214-A / ST-800 215-A

OM-817 Page 2
4. Weld Cable Connections
WARNING
ELECTRIC SHOCK can kill.
•Do not touch live electrical parts.
•Turn Off welding power source, and disconnect input power before making any input or output weld cable connections.
swarn12.1* 2/93
See welding power source Owner’s Manual for weld cable and connection location
information. See wire feeder Owner’s Manual for connection location information
as applicable. See High-Frequency unit Owner’s Manual for connection location
information as applicable.
NOTE
Ref. ST-099 082-C / Ref. ST-098 115-B
1 Electrode 1
2 Electrode 2
3 A Terminal
4 B Terminal
5 C Terminal
1
E #2
E #1
C
B
A
( + )
( −)
FROM ELECTRODE 2
FROM ELECTRODE 1
FROM WORK
FROM
POWER
SOURCE
S1
2 345
Tools Needed:
13/16 in
Figure 4-1. One Electrode Positive (+) And One Electrode Negative (−) Connection

OM-817 Page 3
Ref. ST-099 082-C / Ref. ST-098 115-B
1 Electrode 1
2 Bus Bar
3 Electrode 2
4 A Terminal
5 B Terminal
6 C Terminal
Tools Needed:
13/16 in
E #2
E #1
C
B
A
( + )
( −)
CONNECT BUS BAR
FROM ELECTRODE
FROM WORK
FROM
POWER
SOURCE
S1
E #1 TO E #2
13 4562
Figure 4-2. One Electrode Either Polarity Connection
Ref. ST-099 082-C / Ref. ST-098 115-B
1 Electrode 1
2 Electrode 2
3 A Terminal
4 Bus Bar
5 B Terminal
6 C Terminal
Tools Needed:
13/16 in
E #2
E #1
C
B
A
( + )
FROM ELECTRODE 2
FROM ELECTRODE 1
FROM
POWER
SOURCE
S1
CONNECT WORK TO POWER SOURCE ( −)
CONNECT BUS BAR
A TO B
12 3 564
Figure 4-3. Two Electrodes Same Polarity Connection (Electrode Positive Shown)

OM-817 Page 4
Ref. ST-099 082-C / Ref. ST-098 115-B
1 Electrode 1
2 Electrode 2
3 A Terminal
4 B Terminal
5 C Terminal
Tools Needed:
13/16 in
E #2
E #1
C
B
A
MIN. IND.
MAX. IND.
FROM ELECTRODE 2
FROM ELECTRODE 1
FROM
POWER
SOURCE
S1
CONNECT WORK TO POWER SOURCE ( −)
12 345
Figure 4-4. One Electrode CV And One Electrode CC Connection
(For Welding Power Source With CV And CC Terminals)
5. Remote 14 Receptacles Information
Socket* Socket Information
A24 volts ac.
BContact closure to A completes 24 volts ac contactor control
circuit.
Remote Contactor I115 volts ac.
JContact closure to I completes 115 volts ac contactor control
circuit.
AJ
GCircuit common for 24 and 115 volts ac circuits.
AJ
BKICCommand reference; +10 volts dc output to remote control.
B
CLNH
DMG
Remote
Amperage/Voltage
DRemote control circuit common.
DMG
EF
A
mperage
/V
o
l
tage
Control E0 to +10 volts dc input command signal from remote control.
E
KChassis common.
*The remaining sockets are not used.

OM-817 Page 5
6. Welding Power Source Remote 14 Receptacle And 115 Volt Receptacle Connections
ST-800 201-A / Ref. 800 101
1 Remote Control Plug
Connect to the welding power
source Remote 14 receptacle.
2 115 Volt Receptacle
Connect 115 volt plug from
HF-252D-1 high frequency unit.
NOTE: Do not make any other con-
nections to this receptacle.
YPin K in welding power
source must be grounded.
See welding power source
circuit diagram to be sure.
1
2
7. Operation
ST-800 202-A / Ref. ST-162 505-A
1 Process Selector Switch
Make connections according to
Section 4. Place switch in correct
position for application. For GTAW
DC Electrode Negative (DCEN),
use Process 2 position. For GMAW
or SMAW DC Electrode Positive
(DCEP), use Process 1 position.
YArcing can damage switch.
Do not change Process Selector
switch position while welding.
YUsing unit with switch
between positions can dam-
age switch.
Place switch lever fully left or right.
1
8. Duty Cycle
3 Minutes Welding 7 Minutes Resting
Duty Cycle is percentage of 10 minutes
that unit can weld at rated load without
overheating.
Y30% Duty Cycle at 650 Amperes. Ex-
ceeding duty cycle can damage unit
and void warranty.

OM-817 Page 6
9. Routine Maintenance
YDisconnect power before maintaining.
3 Months
Replace
Unreadable
Labels
Repair Or
Replace
Cracked
Cables
Clean
And
Tighten
Weld
Terminals
6 Months
Blow Out
Or
Vacuum
Inside
During Heavy
Service,
Clean Monthly
OR
When Necessary
Use a high temperature grease such as MILLER Part No. 156 738 to grease the switch mechanism.
10. Troubleshooting
Trouble Remedy
Switch does not work. Check connections and Process Selector switch position for desired application. If switch still does
not work, contact nearest Factory Authorized Service Agent.

OM-817 Page 7
11. Electrical Diagram
SB-177 083-B
Figure 11-1. Circuit Diagram

OM-817 Page 8
12. Parts List
ST-801 362
1
2
4
5
6
7
8910 11
13
14
15
171819
20
21
3
22
23
24
25
26
27
28
29
16
12
Figure 12-1. Complete Assembly

OM-817 Page 9
Description
Part
No.
Dia.
Mkgs.
Item
No.
Figure 12-1. Complete Assembly
Quantity
1 134 327 LABEL, warning general precautionary 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 +159 588 WRAPPER 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 159 587 DOOR, rear 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 010 916 CONNECTION, cable clamp .075 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5 180 008 CABLE, interconnection 10ft .600 in 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 1T 099 255 TERMINAL, pwr output neutral (consisting of) 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7 601 976 SCREW, .500-13 x 1.500 hexhd stl 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8 039 040 TERMINAL BOARD, neutral 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9 039 044 BUS BAR, term bd 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10 601 880 NUT, .500-13 x .31 high stl 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11 601 879 NUT, .500-13 x .44 high stl 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12 S1 117 914 SWITCH, selector 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13 S2 603 946 SWITCH, mag blwt lim 10A 125/250VDC SPDT 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14 C1 180 006 CAPACITOR, cer disc 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15 117 913 BRACKET, mtg switch 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16 177 568 PLATE, control 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17 RC3 134 837 RECEPTACLE, str grd 2P3W 15A 125V 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18 RC1, 2 143 976 RECEPTACLE w/SOCKETS, (consisting of) 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
152 486 CONNECTOR, circ skt 14-18ga 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19 CR2, 3 072 817 RELAY, encl 24VAC DPDT 20A/120VAC 8 pin 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20 180 009 CASE SECTION, front/bottom/rear 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21 NAMEPLATE, (order by model and serial number) 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22 010 650 PIN, spring CS .125 x 1.000 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23 019 663 MOUNT, nprn 15/16 OD 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24 019 603 KNOB, ball 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25 091 597 HANDLE, switch 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
26 CR1 140 772 RELAY, encl 24VAC 4PDT 5A/110VAC 14 pin 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
27 116 005 BLOCK, term 20A 7 pole 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
108 023 LINK, jumper term blk 10A 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28 097 132 STAND-OFF, 6-32 x .375 lg .250 hex brs 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29 PC1 166 064 CIRCUIT CARD ASSEMBLY, receptacle bypass 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PLG30,31 130 203 CONNECTOR, rect mini .045 12skt 2 row (consisting of) 2. . . . . . . . . . . . . . . . . . . . . . . .
113 746 CONNECTOR, rect mini 045skt 18-24CA 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
098 471 BUS BAR, interconnecting (1/8 x 1-1/4 x 3-3/8) 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
098 468 BUS BAR, interconnecting (1/8 x 1” x 2-1/8) 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
098 466 BUS BAR, interconnecting (1/8 x 1” x 2-5/8) 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
098 465 BUS BAR, interconnecting (1/8 x 1” x 3-1/4) 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
098 469 BUS BAR, interconnecting (1/8 x 1” x 3-3/4) 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
098 467 BUS BAR, interconnecting (1/8 x 1” x 4-1/2) 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
059 805 TUBING, cop .540 OD x .123 wall x .312 lg 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
059 804 TUBING, cop .540 OD x .123 wall x .437 lg 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
049 633 TUBING, cop .540 OD x .123 wall x .500 lg 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
049 611 TUBING, cop .540 OD x .123 wall x .687 lg 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
145 898 BRACKET, mtg PR/IC rear 1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
145 900 BRACKET, mtg PR/IC front 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
+When ordering a component originally displaying a precautionary label, the label should also be ordered.
BE SURE TO PROVIDE MODEL AND SERIAL NUMBER WHEN ORDERING REPLACEMENT PARTS.