Miller RHC-NT456-NPN User manual

©2007 MILLER Electric Mfg. Co.
OWNER’S MANUAL OM-235 844A
2007−10
RHC−NT456−NPN
1. Safety Symbol Definitions
Warning! Watch Out! There are possible hazards as
shown in the adjoining symbols. Have only trained and qualified persons install, operate, or service this unit. Call your distributor if you do not
understand the directions. For WELDING SAFETY and
EMF information, read power source Manual.
Beware of electric shock from wiring. Keep all panels and
covers closed. 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.
Wear safety glasses with side shields.
2. Specifications And Connections
805 069-A / 805 090-A
1 RHC−NT456−NPN
2 RHC−NT Interconnect Cable
3 14-Pin Plug (Short Cord)
Connect to matching receptacle on
RHC remote control, or to optional
extension cord.
4 14-Pin Plug (Long Cord)
Connect to matching receptacle on
welding power source.
5 Metal Plug
Connect to matching receptacle on
wire feeder, or to customer supplied
extension cord.
6 Ring Terminal
Connect ring terminal to negative
(−) weld output terminal on welding
power source.
A 4-1/4 in
(108 mm)
B 5-1/2 in
(140 mm)
C 6-7/8 in
(175 mm)
B
C
A1
23
4
5
6

OM-235 844 Page 2
3. Operation
234 989-A
1 Voltage/Amperage/Trim
Adjustment Control
Turn control clockwise to increase
value. The active value is displayed
on the power source displays, and
changes as the control knob is ro-
tated. Control can be adjusted while
welding.
2 Mode Switch
Use switch to select weld process.
When Panel is selected on the RHC
control, the welding process se-
lected on the welding power source
will be active. If either Pulse or MIG
is selected on the RHC control, it
becomes the active process and
overrides whatever process is se-
lected on the welding power
source.
!If the mode switch on the
welding power source is in a
electrode hot position, and
the mode switch on the RHC
is in the panel position, the
contactor is on.
1
2
4. Routine Maintenance
.Maintainmore often
during severe conditions.
!Disconnect power
before maintaining.
n= Check Z= Change ~= Clean l= Replace
* To be done by Factory Authorized Service Agent
Everyday Every 3
Months
Cord(s)
Move control from min to max nl n l
5. Troubleshooting
Trouble Remedy
No voltage control. Set switches and controls on welding power source (see welding power source Owner’s Manual).
Check weld output on welding power source (see welding power source Owner’s Manual).
Secure cord connections or replace cord, if necessary.
No output (contactor) control. Remote Hand Control switch in wrong position.
Check switch settings and weld output on welding power source (see welding power source Owner’s
Manual).
Secure cord connections or replace cord, if necessary.

OM-235 844 Page 3
6. Circuit Diagrams
235 072-A
RHC−NT456−NPN

OM-235 844 Page 4
7. Parts List
805 070-A
.Hardware is common and
not available unless listed.
1
2
3
4
5
67
89
10
11
12
13
14
Figure 7-1. Complete Assembly
Description
Part
No.
Dia.
Mkgs.
Item
No.
Figure 7-1. Complete Assembly
Quantity
1 234 992 WRAPPER, INSIDE 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 NAMEPLATE, RHC−14 (ORDER BY MODEL AND SERIAL NUMBER) 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 174 991 KNOB, POINTER 1.250 DIA X .250 ID W/SPRING CLIP−.21 1. . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 604 645 NUT, 375−32 .56HEX .09H STL CAD USE W/POTS 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5 605 321 NUT, 468−32 .56HEX .09H BRS BLK USE W/SWITCHES 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 235 272 POTENTIOMETER, W/LEADS 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7 189 404 SPACER, NYLON .718 OD X .526 ID X .281 LG 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8 235 271 SWITCH, W/LEADS 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9 234 996 CABLE, INTERCONNECT RHC−NT 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10 234 994 RECEPTACLE, W/LEADS 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11 234 766 CIRCUIT CARD ASSY, RHC-NT 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12 +234 991 WRAPPER, OUTSIDE 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13 085 220 LABEL,CAUTION ELECTRIC CIRCUIT 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14 190 512 STAND−OFF, NO 6−32 X .640 LG .250 HEX AL FEM 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
+When ordering a component originally displaying a precautionary label, the label should also be ordered.
BE SURE TO PROVIDE MODEL AND STYLE NUMBER WHEN ORDERING REPLACEMENT PARTS.