Nelson NCD+ Instruction & Maintenance Manual

These instructions are for experience operators.

If you are not fully familiar with the principles of operation and safe practices for arc welding equipment, we urge you to read AWS SP – “Safe Practices” available from the American Welding Society.

Do not permit untrained persons to install, operate or maintain the equipment. Do not attempt to install or operate the equipment until you have read and fully understand these instructions.

If you do not fully understand these instructions, contact your supplier for further information. Be sure to read the Safety section before utilizing this equipment.

Operating the NCD+Contact Gun

Instruction & Maintenance Manual

NCD+ Limited Warranty

Nelson’s only warranty is that goods being sold will be free from defects in

workmanship and material. This warranty is expressly in lieu of other warranties, expressed or implied and whether statutory or otherwise, including any implied warranty of merchantability or fitness for a particular purpose.

Nelson’s liability for breach of warranty shall arise only upon return of the defective goods at Buyer’s expense after notice to Nelson of the claimed

breach, and shall be limited to furnishing a like quantity of such goods free from such defects or, at Nelson’s option, to refunding the purchase price (less reasonable depreciation based on actual use); provided, however, that Nelson will not accept receipt of equipment returned unless buyer has

previously afforded Nelson’s personnel a reasonable opportunity to inspect and repair said equipment at buyer’s facility or such other location as is

mutually agreeable. Notice to Nelson must be given within 30 days of such defect or failure and within 90 days from the date the equipment was delivered. No compensation or reimbursement for transportation costs of any kind will be allowed.

Please note that this warranty does not extend beyond the original registered purchaser, and does not warrant equipment that has been modified by any party other than Nelson, or equipment that has been improperly installed, improperly operated, or misused based upon industry standards, or equipment which has not had reasonable and necessary maintenance, or equipment which has been used for operation outside of specifications for the equipment. Nelson shall never be liable for consequential damages.

Nelson reserves the right to make engineering and/or part changes, at any time without notice, as a result of our commitment to continuous improvement.

WARNING

The following Safety section is for your protection. It summarizes precautionary information from

the references listed in the Additional Safety Information section. Before performing any installation or operating procedures, be sure to read and follow the safety precautions listed below as well as all other manuals, material safety data sheets, labels, etc. Failure to observe these precautions can result in injury or death.

ELECTRICAL SHOCK Contact with live electrical parts and ground

can cause severe injury or death. DO NOT use welding current in damp areas, if movement is confined, or if there is danger of falling. Therefore:

1. Be sure the power source frame (chassis) is connected to the

ground system of the input power.

2. Connect the work piece to a good electrical ground.

3. Connect the work cable to the work piece. A poor or missing

connection can expose you or others to a fatal shock.

4. Use well-maintained equipment. Replace worn or damaged

cables..

5. Keep everything dry, including clothing, work area, cables,

torch/electrode holder and power source.

6. Make sure that all parts of your body are insulated from work

and from the ground.

7. Do not stand directly on metal or the earth while working in tight

quarters or a damp area; stand on dry boards or an insulating platform and wear rubbersoled shoes.

8. Put on dry, hole-free gloves before turning on the power.

9. Refer to ANSI/ASC Standard Z49.1 for specific grounding

recommendations. Do not mistake the work lead for a ground cable.

PROTECT YOURSELF AND OTHERS Some welding, cutting, and gouging processes

are noisy and require ear protection. The arc, like the sun, emits ultraviolet (UV) rays and other radiation which can harm the skin and

eyes. Hot metal can cause burns. Training in the proper use of the processes and equipment is essential to prevent accidents. Therefore:

1. Always wear safety glasses with side shields in any work area,

even if welding helmets, face shields and goggles are also required.

2. Use a face shield fitted with filter shade #3 per ANSI Z87.1.

Cover sparks and rays of the arc when operating or observing operations. Warn bystanders not to watch the arc and not to expose themselves to the rays of the electric-arc or hot metal.

3. Wear flameproof gauntlet type gloves, heavy long-sleeve shirt,

cuffless trousers, high topped shoes, and a welding helmet or cap for hair protection, to protect against arc rays and hot sparks or hot metal. A flameproof apron may also be desirable as protection against radiated heat and sparks.

4. Hot sparks or metal can lodge in rolled up sleeves, trousers cuffs

or pockets. Sleeves and collars should be kept buttoned, and open pockets eliminated from the front of clothing.

5. Protect other personnel from arc rays and hot sparks with

suitable nonflammable partitions or curtains.

6. Use goggles over safety glasses when chipping slag or grinding.

Chipped slag may be hot and can fly far. Bystanders should also wear goggles over safety glasses.

ELECTRICAL AND MAGNETIC FIELDS Electric and magnetic fields may be

dangerous. Electric current flowing through any conductor causes localized Electric and Magnetic Fields (EMF). Welding and cutting current creates EMF around welding cables and welding machines. Therefore:

1. Operators having pacemakers should consult their physician

before welding. EMF may interfere with some pacemakers.

2. Exposure to EMF may have other health effects which are

unknown.

3. Operators should use the following procedures to minimize

exposure to EMF:

4. Route the electrode and work cables together. Secure them

with tape when possible.

5. Never coil the torch or work cable around your body.

6. Do not place your body between the torch and work cables.

Route cables on the same side of your body.

7. Connect the work cable to the work piece as close as possible to

the area being welded.

8. Keep welding power source and cables as far away from your

body as possible.

FIRES AND EXPLOSIONS Heat from flames and arcs can start fires. Hot

slag or sparks can also cause fires and explosions. Therefore:

1. Remove all combustible materials well away from the work area

or cover the materials with a protective nonflammable covering. Combustible materials include wood, cloth, sawdust, liquid and gas fuels, solvents, paints and coatings, paper, etc.

2. Hot sparks or hot metal can fall through cracks or crevices in

floors or wall openings and cause a hidden smoldering fire or fires on the floor below. Make certain that such openings are protected from hot sparks and metal.

3. Do not weld, cut, or perform other hot work until the work piece

has been completely cleaned so that there are no substances on the work piece which might produce flammable or toxic vapors. Do not do hot work on closed containers. They may explode.

4. Have appropriate fire extinguishing equipment handy for instant

use, such as a garden hose, water pail, sand bucket or portable fire extinguisher. Be sure you are trained for proper use.

5. Do not use equipment beyond its ratings. For example,

overloaded welding cable can overheat and create a fire hazard.

6. After completing operations, inspect the work area to make

certain there are no hot sparks or hot metal which could cause a later fire. Use fire watchers when necessary.

7. For additional information, refer to NFPA Standard 51B, “Fire

Prevention in Use of Cutting and Welding Processes,” available

from the National Fire Protection Association, Batterymarch Park, Quincy, MA 02269

FUMES AND GASES Fumes and gases can cause discomfort or

harm, particularly in confined spaces. Do not breathe fumes and gases. Shielding gases can cause asphyxiation. Therefore:

1. Always provide adequate ventilation in the work area by natural

or mechanical means. Do not weld, cut, or gouge on materials such as galvanized steel, stainless steel, copper, zinc, lead, beryllium, or cadmium unless positive mechanical ventilation is provided. Do not breathe fumes from these materials.

2. Do not operate near degreasing and spraying operations. The

heat or arc rays can react with chlorinated hydrocarbon vapors to form phosgene, a highly toxic gas, and other irritant gasses.

3. If you develop momentary eye, nose, or throat irritation while

operating, this is an indication that ventilation is not adequate. Stop work and take necessary steps to improve ventilation in the work areas. Do not continue to operate if physical discomfort persists.

4. Refer to ANSI/ASC Standard Z49.1 (see listing on next page) for

specific ventilation recommendations.

ELECTRICALLY POWERED EQUIPMENT Faulty or improperly electrified equipment can

cause injury or death. Therefore:

EYE PROTECTION Flying metal can injure eyes. Welding, chipping,

wire brushing and grinding can cause sparks and flying metal. As welds cool, they can throw off slag. Therefore:

1. Always have qualified personnel perform the installation,

troubleshooting, and maintenance work. Do not perform any electrical work unless you are qualified to perform such work.

2. Before performing any work inside a power source, disconnect the

power source from the incoming electrical power using the disconnect switch at the fuse box before working on the equipment.

3. Install equipment in accordance with the U.S. National Electrical

Code, all local codes and the manufacture’s recommendations.

4. Ground the equipment in accordance with the U.S. National

Electrical Code and the manufacturer’s recommendations.

1. Wear approved safety glasses with side shields even under your

welding helmet.

2. Warn others nearby about flying metal hazard.

EQUIPMENT MAINTENANCE Faulty or improperly maintained equipment can

cause injury or death. Therefore:

CYLINDER HANDLING Cylinders, if mishandled, can rupture and

violently release gas. Sudden rupture of cylinder, valve, or relief device can injure or kill. Therefore:

1. Always have qualified personnel perform the installation,

troubleshooting, and maintenance work. Do not perform any electrical work unless you are qualified to perform such work.

2. Before performing any maintenance work inside a power source,

disconnect the power source from the incoming electrical power.

3. Maintain cables, grounding wire, connections, power cord, and

power supply in safe working order. Do not operate any equipment in faulty condition.

4. Do not abuse any equipment or accessories. Keep equipment away

from:

 heat sources such as furnaces  wet conditions such as water puddles and inclement weather  oil or grease  corrosive atmospheres

5. Keep all safety devices and cabinet covers in position and in good

repair.

6. Use equipment only for its intended purpose. Do not modify it in

any manner.

1. Use the proper gas for the process and use the proper pressure

reducing regulator designed to operate from the compressed gas cylinder. Do not use adaptors. Maintain hoses and fittings in good condition.

2. Always secure cylinders in an upright position by chain or strap to

suitable hand trucks, undercarriages, benches, walls, post, or racks. Never secure cylinders to work tables or fixtures where they may become part of an electrical circuit.

3. When not in use, keep cylinder valves closed. Have valve

protection cap in place if regulator is not connected. Secure and move cylinders by using suitable hand trucks. Avoid rough handling of cylinders.

4. Locate cylinders away from heat, sparks, and flames. Never strike

an arc on a cylinder.

5. For additional information, refer to CGA Standard P-1, “Precautions

for Safe Handling of Compressed Gases in Cylinders”, which is

available from Compressed Gas Association, 1235 Jefferson Davis Highway, Arlington, VA 22202.

ADDITIONAL SAFETY INFORMATION For more information on safe practices for

electric arc welding, refer to the following publications.

HEARING PROTECTION Prolonged Noise from Capacitor Discharge

welding applications can damage hearing if levels exceed limits specified by OSHA. Therefore:

1. ANSI/ASC Z49.1 Safety in Welding and Cutting

2. AWS C5.1 Recommended Practices for Plasma Arc Welding

3. AWS C5.6 Recommended Practices for Gas Metal Arc Welding

4. AWS SP Safe Practices (Reprint) Welding Handbook

5. ANSI/AWS F4.1 Recommended Safe Practices for Welding and

Cutting of Containers That Have Held

Hazardous Substances.

1. Use Approved ear plugs or ear muffs if noise level is high.

2. Warn others nearby about noise hazard.

3. For additional information, refer to OSHA Safety Standards 3074.

MOVING PARTS CAN CAUSE INJURY Electric fan can start at any time without

warning and cause severe injury, therefore:

1. Always disconnect electrical power prior to service to prevent the

fan from starting unexpectedly.

2. Keep all doors, panels, covers, and guards closed and securely in

place.

3. Have only qualified people remove guards or covers for

maintenance and troubleshooting as necessary.

4. Keep hands, hair, loose clothing, and tools away from moving

parts.

5. Reinstall panels or guards and close doors when servicing is

finished and before reenergizing welder.

Contents

1 Overview ....................................................................................................................... 7

1.1.1 Contact Mode Capacitor Discharge Welding ........................................................... 8

1.2 NCD+ Contact Guns ................................................................................................. 8

1.2.1 Operation of the Contact Gun .............................................................................. 8

1.2.2 Operation of Contact Gun with LED Option ............................................................ 8

2 LED Option .................................................................................................................... 9

3 Features ...................................................................................................................... 10

4 Gun Set-Up .................................................................................................................. 11

4.1 Setting Up Chuck Assembly ..................................................................................... 11

4.1.1 Setting Up Chuck ............................................................................................. 11

4.1.2 Adjusting Chuck and Stop Assembly ................................................................... 11

4.1.3 Adjusting Stud Stop Assembly ........................................................................... 12

4.2 Setting Up Foot and Leg Assembly ........................................................................... 12

4.3 Setting Spring Pressure .......................................................................................... 13

5 Weld Setup .................................................................................................................. 14

6 Maintenance of Stud Welding System .............................................................................. 15

6.1 Stud Welding Gun .................................................................................................. 15

6.2 Welding Cable / Control Cable ................................................................................. 15

6.3 Power Control Unit ................................................................................................. 15

7 Troubleshooting ............................................................................................................ 16

7.1 Visual Weld Inspection and Weld Parameter Adjustments ............................................ 16

7.2 Weld Quality Physical Inspection and Weld Parameter Adjustments .............................. 16

7.2.1 Recommendations ........................................................................................... 16

8 Exploded Drawings & Parts List ...................................................................................... 19

8.1 Contact Gun (751-650-600) .................................................................................... 19

8.1.1 Parts List ........................................................................................................ 19

8.1.2 Exploded Drawing ............................................................................................ 21

8.2 Contact Gun with LED Option (751-650-610) ............................................................. 22

8.2.1 Parts List ........................................................................................................ 22

8.2.2 Exploded Drawing ............................................................................................ 24

8.3 Electrical Functions of Guns ..................................................................................... 25

8.3.1 Triggering Contact ........................................................................................... 25

8.4 Gun Coding ........................................................................................................... 25

8.4.1 Dismantling & Reassembling Welding Guns ......................................................... 25

9 Schematics .................................................................................................................. 26

9.1 NCD+ CTRL to GUN, 7 PIN, Contact ......................................................................... 26

9.2 NCD+ CTRL TO GUN, 12 PIN W/LED, Contact ............................................................ 28

10 Technical Specifications ............................................................................................. 29

10.1 Specifications ........................................................................................................ 29

10.1.1 Gun Dimensions .............................................................................................. 29

10.2 Accessories ........................................................................................................... 30

11 Contact Information .................................................................................................. 31

A Table of Weld Parameters .............................................................................................. 32

B Spring Pressure Chart ................................................................................................... 33

1 Overview

SAFETY SYMBOLS

ATTENTION! BE ALERT! Your safety is involved.

Used to call attention to immediate hazards which, if not avoided, will result in immediate, serious personal injury or loss of life.

Used to call attention to potential hazards which could result in personal injury or loss of life.

Used to call attention to hazards which could result in minor personal injury.

The Nelson NCD+ stud welding gun is made to be used with Nelson NCD+ stud welding power units, which utilize the capacitor discharge principal of stud welding. This system is designed to use fasteners, which are manufactured with a small projection on the weld end and are welded by the Contact method. Heat for fusion is obtained from an electric arc, which is established by flashing away the small projection. The discharge of the welding current or energy stored in the capacitors produces an arc that melts the end of the stud and a portion of the base material. The stud is forced into the molten metal before the conclusion of the arc cycle. Upon cooling, a uniform cross section bond is achieved. A special advantage of the capacitor discharge process is the limited heat generated, and low penetration which allows the fasteners to be welded to thin and/or coated parts opposite the weld side.

Contact welding is generally used with carbon steel and stainless steel especially when weld appearance is not a prime consideration. The contact welding setup is easy and is tolerant to workpiece flexing.

The welding gun is a “contact gun” which is suitable only for contact welding.

NOTE: Depending upon the weld setup established for any particular stud size or material, the noise generated by the flashing away of the stud tip may exceed the allowable level established by the Occupational Safety and Health Administration (Section 50-204.10 of the Federal Register, Part II). For this reason, it is recommended that the stud welding operator and anyone working within the immediate area of the stud welding operation use proper ear protection.

1.1.1 Contact Mode Capacitor Discharge Welding

1.2 NCD+ Contact Guns

This manual covers the NCD+ welding gun series including the Contact gun and the Contact gun with the LED Option. These guns are very similar from the outside, however they are not interchangeable. Each gun has its own specific mode of welding studs. The internal parts that are different will be identified so you can easily determine which gun you have.

1.2.1 Operation of the Contact Gun

The NCD+ Contact Gun is a capacitor discharge contact gun. Since there is no coil, there is only one wire that goes to the trigger. The other side of the trigger goes to the foot assembly. When the trigger is pulled, the capacitors discharge as the stud is held firmly against the workpiece. The tip is flashed off allowing the arc and stud plunge.

1.2.2 Operation of Contact Gun with LED Option

The LED option provides the user with remote indication of whether or not the unit is ready to weld and after the weld if the measured values were within the selected weld parameters.

2 LED Option

3 Features

1

CHUCK NUT

6

LEG SCREWS

2

TRIGGER

7

SPRING PRESSURE GAUGE

3

CONTROL CABLE

8

SPRING PRESSURE ADJUSTMENT

4

WELD CABLE

9

GUN BODY (2 HALVES)

5

LED STATUS

Figure 3.1 Contact Gun

Refer to Setting Up Foot and Leg Assembly.

4 Gun Set-Up

The unit should be switched off before inserting or changing a chuck.

Figure 4.1 Chuck and Stop Assembly

4.1 Setting Up Chuck Assembly

4.1.1 Setting Up Chuck

At the beginning of a welding series or in case of a necessary change to different stud dimensions, the chuck must be set to the correct stud type.

The chucks (Figure 4.1 Chuck and Stop Assembly) are not included and should be ordered separately. See Accessories for correct sizes and part numbers.

Job Preparation

Tools Required: Screwdriver, open-end wrench (7mm, 8mm), and caliper gauge

1 Select chuck with the correct diameter for the stud to be welded. 2 Stop pin assembly for the proper stud length.

4.1.2 Adjusting Chuck and Stop Assembly

The unit should be switched off before inserting or changing a chuck.

To adjust the Chuck and Stop Assembly (Figure 4.1 Chuck and Stop Assembly):

The proper size chuck for the type of stud being welded must be used to ensure good electrical contact between the stud and the stud chuck. If the stud fit seems too loose with the proper chuck, the chuck tines may be pressed slightly together at the front end of the chuck.

NOTE: There must be good electrical contact between the stud to be welded and the stud chuck. It may be useful to press the tines of the chuck together slightly at the front.

NOTE: During welding, it is very important to draw the chuck (gun) straight off the stud after a weld has been made to avoid spreading the chuck tines. If this procedure is not followed, chuck life may be substantially shortened.

4.1.3 Adjusting Stud Stop Assembly

1 Loosen the set screw. 2 Adjust the stud stop (Figure 4.1 Chuck and Stop Assembly) so that the stud being welded

extends 4 mm beyond the chuck.

3 Tighten set screw.

NOTE: For long studs, use maximum chuck depth. The chuck is assembled as shown and inserted into the chuck adaptor. The chuck must be in firm contact with the stud stop while tightening the chuck nut.

4.2 Setting Up Foot and Leg Assembly

The NCD+ guns come supplied with a foot and spark shield (Figure 4.2 Foot & Leg Assembly). The foot is installed on the end of the legs. Alignment of the foot is important. The chuck should be located in the center of the spark shield. To install the foot, unscrew the leg screws and place them through the holes in the foot. Reattach the leg screws to the legs. Maintain concentricity between the chuck and spark shield.

Figure 4.2 Foot & Leg Assembly

4.3 Setting Spring Pressure

Required tools: NCD+ Weld gun, chuck and foot per application, NCD+ Set-Up Tool (Figure 4.3 Contact Gun with NCD+ Set-Up Tool #525-001-200) or flat bladed screwdriver

1 Check Appendix B Spring Pressure Chart for the recommended spring pressure. 2 With a flat bladed screwdriver or NCD+ Set-Up Tool, turn adjustment screw on the back of the

weld gun to the recommended spring pressure.

3 Adjust stud stick out. 4 Loosen leg screws. 5 Insert stud in chuck 6 Place NCD+ Set-Up Tool on a flat surface and insert stud into Contact Mode hole. 7 Do not compress the spring. 8 Adjust foot until tripod foot or spark shield are flat on top of NCD+ Set-Up Tool. Do not insert

tripod standoffs into holes on tool.

9 Tighten leg screws to lock tripod foot or spark shield in place.

Figure 4.3 Contact Gun with NCD+ Set-Up Tool #525-001-200

5 Weld Setup

1 Confirm that the unit is switched off.

NOTE: Combo cable is normally used with the Contact mode.

2 Connect gun, combo cable and ground cables to the appropriate terminals. 3 Determine initial weld parameters in the Table of Weld Parameters. 4 Adjust voltage. 5 Install chuck and stud stop. 6 Adjust gun spring pressure. 7 Adjust plunge.

Plunge is the distance the stud extends beyond the stand-off posts (or spark shield). Loosen the leg locking screws and adjust the plunge to approximately 3mm and retighten the leg locking screws.

8 Switch the power unit on. 9 Check concentricity of chuck and spark shield. 10 Begin production welding after samples weld have been validated for strength and appearance. 11 For finer contact gun adjustments, refer to Error! Reference source not found..

6 Maintenance of Stud Welding System

A majority of the maintenance of a stud welding system is in:

1 Stud Welding Gun 2 Welding Cable / Control Cable 3 Power Control Unit

6.1 Stud Welding Gun

The weld tool carries out most of the welding functions and should be periodically (at least every 3 months) disassembled and cleaned. Special attention should be given to the spring mechanism. This shaft must be absolutely free with no binding inside the gun and there should be no contact between the stud and the spark shield. Never lubricate the spring mechanism. It should be cleaned with a dry cleaner such as electrical contact cleaner. Caution should also be exercised when reassembling the gun to be certain not to pinch wires or the weld cable. This could cause erratic welding problems which are usually difficult to isolate.

6.2 Welding Cable / Control Cable

When checking cables for continuity, it is important to slightly pull on all the connectors so that if there is a break, the wires will be pulled apart. The continuity check can be performed with a standard Ohm meter. All cables: ground, control and the weld cables should be periodically inspected.

6.3 Power Control Unit

The power control unit contains electronic control boards. Normally, these items do not require maintenance. However, in harsh environments, particularly those with grinding or sanding, metallic dust can enter the welder. This conductive metallic dust can cause unexplained problems with the welding system. Periodically removing the power control unit cover and blowing out the power control unit is a good idea. Frequency will vary depending on the environment. Always disconnect power before opening any power control unit. CD units will continue to store energy after they have been unplugged. To ensure all energy is discharged, wait at least one minute before removing cover and servicing the power control unit. Use voltmeter to check voltage between (+) & (-) grid for 0 Volts.

7 Troubleshooting

Issue:

Cold Weld

Issue:

Acceptable Weld

Issue:

Hot Weld

7.1 Visual Weld Inspection and Weld Parameter Adjustments

Figure 7.1 Weld Quality Visual Inspection

7.2 Weld Quality Physical Inspection and Weld Parameter Adjustments

If visually inspecting the welds reveals a questionable weld, the weld should be physically tested. Initial weld set ups should also be physically tested.

Suggested physical tests for steel and stainless steel studs are as follows:

1 Bend Test. Stud to be tested shall be bent away from its vertical axis 90° or until failure.

Failure should occur in the stud proper, or, on thin plate, a full stud diameter plug of base metal should be torn out.

2 Torque Test. Stud shall be torqued until a pre- specified loading is attained or until the stud

fails or, on thin plate, a plug of the base material should tear out.

Physical test procedures for inspecting (magnesium) aluminum alloy studs are:

3 Bend Test. The stud to be tested shall be bent, using a bending tool approximately 15° away

from its vertical axis before the stud breaks in the weld shank or the base material fails.

NOTE: Do not bend aluminum studs by striking with a hammer, always use a bending tool.

4. Torque Test. The stud to be tested shall be torqued in the conventional manner by applying torque until the stud fails or a predetermined torque load is reached.

7.2.1 Recommendations

Before starting any stud welding operation, or after the equipment has remained idle for a period of time, trial or test studs should be welded to a plate for testing. Testing should continue until there is no failure of a test stud.

Weld Issue

Weld Parameter Adjustments

Cold Weld

Weld failure at low value, no weld flash or splatter, and weld base is incompletely melted (very weak weld). This indicates that not enough heat was available.

Weld heat may be increased by:

 Reducing spring pressure - Reducing the drop speed and provides

a longer weld time.

 Increasing voltage - Increasing the voltage increases overall

energy into the weld.

 Check stud ignition tips (possibly too short).

Hot Weld Weld failure at low value, excessive weld flash and splatter, and weld base may be undercut (weak weld). This indicates that too much heat was available.

Weld heat may be decreased by:

 Increasing spring pressure - Speeding up the weld time and

extinguishes the arc sooner.

 Decreasing voltage - Reducing the voltage reduces overall energy

into the weld.

 Check stud ignition tips (possibly too long).

Late or Cold Plunge Cold plunge occurs when the stud contacts the base material after solidification of the molten weld metal has started. This results in inconsistent weld strength and is recognized by a shiny, mirror-like appearance in the fracture surface.

This issue can be rectified by:

 Increasing spring pressure - Increasing drop speed and gets the

stud into the molten pool faster.

 Decreasing voltage - Reducing the voltage reduces overall energy

into the weld.

 Make certain that combo cable is installed (contact mode only).

Otherwise (if gap mode), remove combo cable - Reducing the amount of weld energy flowing especially in gap mode because of the high current spike.

Misfire No arc initiation due to tip failing to flash.

This issue can be rectified by:

 Increasing voltage.  Using 10% detergent solution spray mist.

Problem: Cold Weld

Possible Causes

Possible Solutions

Coiled weld or ground cables. This reduces weld current delivered to the stud. The coiled cables act like a large inductor and inhibit the flow of energy.

Ensure weld and ground cables are not coiled during the stud welding process.

Improperly set power supply controls.

Refer to the Section 3 Normal Operation within the Operating the Capacitor Discharge NCD+ Stud Welding Unit manual.

Improperly formed tip on stud due to manufacturing process.

Replace stud with one that is correctly formed.

Changes in alloys being welded.

Changes in alloys can usually be compensated for by changing the settings on the power supply.

Equipment failure.

Refer to the Section 3 Normal Operation within the Operating the Capacitor Discharge NCD+ Stud Welding Unit manual.

Varying gauges of sheet metal.

Changes in sheet metal can usually be compensated for by changing the settings on the power supply.

Springs inside weld tool have fatigued and don’t apply the same pressure.

Return weld tool to Nelson for service.

Dirt inside weld tool prevents smooth operation and hangs up or slows gun operation.

Return weld tool to Nelson for service.

Problem: Arc Blow

Characterized by weld spatter of fillet on only one side of the stud (looks like molten metal was “blown” out from only the one side of the stud). This problem will often cause incomplete fillet formation on one side of the stud. This incomplete cross sectional welding may lead to weld failure.

Possible Causes

Possible Solutions

Molten metal runs away from the ground. Incomplete or insufficient grounding can cause this problem.

Double Ground. The addition of another ground on opposite sides of the weld area will reduce this problem. The object will be to always weld between the grounds. If you need assistance contact your Nelson Representative.

Welding near the edge (1/4 inch or less) of a piece of metal will potentially cause these phenomena. Unusual electrical current patterns are set up near the edges of metals and this can affect the flow of metal.

Place another piece of sheet metal of the same type and thickness

next to the edge you are welding. This will “fool” the electrical

currents and they will act like you are welding in the middle of the sheet metal.

8 Exploded Drawings & Parts List

ITEM

PART NUMBER

QTY

DESCRIPTION

SPARE?

1

D 751-650-001

1

BODY, GUN, RIGHT

2 D 751-650-002

1

BODY, GUN, LEFT

3 A751-650-003

1

COVER, FRONT

4 A751-650-005

1

CAP, REAR

5 A751-650-006

1

BEARING, FRONT

6 A751-650-007

1

BELLOWS

7 A751-650-008

2

WASHER, LEG

8 A751-650-009

1

NUT, CHUCK

9 A751-650-012

3

PIN, LOCATING

10

A751-650-101

1

ROD ASM, LIFTING

11

A751-650-104

1

BEARING RETAINER

12

A751-650-019

1

SPRING, RETAINER

13

A751-650-020

1

NUT, ADJUSTING, SPRING

14

A751-650-021

1

SCREW, ADJUSTING, SPRING

15

A751-650-022

1

WASHER, FLAT, M4

16

A751-650-211

1

SWITCH ASM, TRIGGER

17

A751-650-027

1

TRIGGER

18

A751-585-021

1

RING, RETAINING

19

87-05-22

1

SPRING, TRIGGER

20

A720-517-000

1

JUMPER, CABLE, WELD

21

524-005-097

4

SCREW, FPS, M5 X 5 LG

22

524-005-007

2

SCREW, SS, M8 X 8MM LG

23

511-001-131

1

SPARK SHIELD

24

524-005-100

3

SCREW, OHM, M4 X 16MM LG

25

524-005-101

2

SCREW, FHSC, M5 X 16MM LG

26

524-005-102

1

SCREW, FHSC, M4 X 12MM LG

8.1 Contact Gun (751-650-600)

8.1.1 Parts List

ITEM

PART NUMBER

QTY

DESCRIPTION

SPARE?

27

524-005-104

1

NUT, THICK, M5

28

524-005-105

1

SCREW, SHC, M5 X 10MM LG

29

524-005-003

1

SCREW, SS, M4 X 6 LG

30

729-023-017

1

WASHER, SPRING, CONICAL, MS

31

A726-013-002

1

COLLET

32

526-001-231

1

SPRING, MAIN

33

A502-001-261

1

FOOT

34

A504-001-056

2

LEG

35

527-003-094

1

BEARING

36

524-005-103

2

SCREW, LHC, M3 X 5MM LG

37

729-023-025

1

PIN, GROOVED, 3MM X 6MM LG

38

713-032-000

4

WIRE SPLICE

39

751-585-004

1

WELD CABLE GROMMET

40

721-268-011

1

CONTROL CABLE, 12 PIN

X

41

720-519-081

1

WELD CABLE

X

42

526-001-232

1

SPRING, GROUND SENSE WIRE

X

Part Number

Qty

Description

524-005-106

1

M5x25 FHSHCS

Additional Parts Needed for Repair

8.1.2 Exploded Drawing

8.2 Contact Gun with LED Option (751-650-610)

ITEM

PART NUMBER

QTY

DESCRIPTION

SPARE?

1

751-650-009

1

CHUCK NUT

2

751-650-007

1

BELLOWS

3 524-005-097

2

SCREW, M5X5 FPSS ZINC

4

751-650-003

1

COVER, FRONT MACHINING

5

524-005-007

2

SCREW, M8X8 FPSS

6 751-650-006

1

FRONT BEARING

7

729-023-017

1

12MM D RETAINING RING

8

526-001-234

1

MAIN SPRING

9 751-650-210

1

WASHER SPRING

10

726-013-002

1

COLLET

11

751-585-021

1

E-RING

12

751-650-027

1

TRIGGER BUTTON

13

87-05-22

1

TRIGGER SPRING

14

751-650-022

1

M4 BRASS WASHER

15

751-650-211

1

TRIGGER ASM SWITCH

16

524-005-105

1

SCREW, M5X10 SHC DIN91

17

751-650-202

1

LIFTING ROD ASM

18

729-023-021

1

PIN, ROLL, CIRCUM 1.5X4

19

524-005-104

1

THICK M5 NUT

20

720-517-000

1

WELD CABLE JUMPER

21

751-650-209

1

WASHER, RESIDUAL

22

751-650-216

1

COIL ASM

23

751-650-217

1

COIL HOLDER

24

524-005-103

1

SCREW, M3X5 LHS DIN7984

X

25

751-650-213

1

ARMATURE, SPRING RETAINER

26

524-005-323

1

STANDOFF, HEX MMC#93655A091

27

526-001-266

1

COMPRESSION RING

28

524-005-330

1

SCREW, M3X10 FPSS MMC#92605A104

29

751-650-219

1

SPRING PRESSURE ADJUSTMENT NUT

30

524-005-324

1

SPACER MMC#92871A171

8.2.1 Parts List

ITEM

PART NUMBER

QTY

DESCRIPTION

SPARE?

31

751-650-222

1

SPRING ADJUSTMENT SCREW

32

751-650-221

1

INDEXING RING

33

524-005-097

1

SCREW, M5X5 FPSS

34

751-650-218

4

REAR LIFT ADJUSTMENT KNOB

35

524-005-331

1

SCREW, THUMB, SS SHEAR-LOC#928B-0305-010S

36

751-650-220

1

REAR SPRING ADJUSTMENT KNOB

37

751-650-214

1

REAR LABEL

38

524-005-320

2

SCREW, M2.5X8 MINI THREAD FORM

39

526-001-232

1

SPRING, GROUND SENSE WIRE

X

40

713-032-000

3

WIRE SPLICE

41

751-585-004

1

CABLE GROMMET

42

721-268-012

1

CONTROL CABLE ASSEMBLY

X

43

720-519-080

1

WELD CABLE ASSEMBLY

X

44

524-005-100

3

SCREW, M4X16 OHMS ZINC

45

751-650-502

1

BODY, WELDGUN, L.H., MOD., L.E.D., NCD+

46

751-650-501

1

BODY, WELDGUN, R.H., MOD., L.E.D., NCD+

47

511-011-131

1

SPARK SHIELD, CD, 46MM

48

751-650-012

3

PIN, LOCATING

49

524-005-106

2

SCREW, M5X25 FHSHCS DI

50

751-650-008

2

WASHER, LEG M5 ZINC

51

502-001-261

1

FOOT, CD GUN

52

504-001-056

2

LEG, 8MM X 110MM, SS

53

103-475-610

1

WIRE, BLACK, 18AWG, 4” OR .333’

54

751-614-005

1

PCB, NCD+ GUN L.E.D.

X

55

751-650-503

1

HOLDER, L.E.D. BOARD

X

8.2.2 Exploded Drawing

8.3 Electrical Functions of Guns

Wire Code

Pin #3

Trigger

Pin #4

Trigger

Pin #5

Gun Coil

Pin #6

Gun Coil

Located in Gun Handle

White

Trigger

Black

Trigger

Brown

Weld Cable

Blue

Safety Bypass (Spring to Front Cover)

Green

Coil

Red

Coil

8.3.1 Triggering Contact

The trigger switch is checked for proper functioning by connecting a continuity tester or ohmmeter at pin 3 of the control plug and to the foot plate.

If the switch provides a proper contact, the continuity tester will emit a signal or the ohmmeter will show 0 ohms.

8.4 Gun Coding

A jumper between pins 1 and 6 tells the power unit that a set lift gun is connected. An ohmmeter will show 0 ohms.

8.4.1 Dismantling & Reassembling Welding Guns

1 Loosen set screws in the front cover 3 and rear cap 4. 2 Remove the caps and lay the gun on its right side. 3 Remove 3 screws that hold the gun halves together. 4 Separate and remove the left gun body such that the internal

components remain in the right half.

5 Inspect parts for damage or excessive wear and replace if necessary. 6 Reassemble in reverse order; making sure that the radial

orientation of the holding coil assembly 8 is such that where the leads emerge from the coil is adjacent to the slot in the right gun body so the leads can be neatly run into the gun handle. The spring adjusting nut 5 should be oriented such that the radial screw fits in the keyway in the gun body and the spring tension gage line is toward the top of the gun.

7 Reassemble the rear cap with the slot towards the top of

the gun and the front cover with its bottom perpendicular to the gun handle.

9 Schematics

9.1 NCD+ CTRL to GUN, 7 PIN, Contact

NCD+ CTRL TO GUN, 12 PIN, Contact

9.2 NCD+ CTRL TO GUN, 12 PIN W/LED, Contact

10 Technical Specifications

Specifications

NCD+™ Contact Gun

Weld Mode

Contact CD

Gap Mechanism

N/A

Spring Pressure

7 lb. (3.2 kg) – 15 lb. (6.8 kg)

Pressure Control

Stepless Tool Adjustment

Gap Control

N/A

Front Ends

Adjustable, Tripod, Spark Shield

Max Stud Length

Depends on Accessories

Dimensions without Cable

6-5/8” x 1-1/2” x 5-1/2”

(169 mm x 38 mm x 140 mm)

Weight without Cable

2.2 lb. (1 kg) Max

Cable Length

19 ft. (5.8 m)

Control Cable Connector

12 Pin Binder

Power Cable Connector

Medium Size Dinse

Maximum Gap

N/A

Stud Capacity (max)

1/4" flanged (NCD+ 1000), 5/16” unflanged (NCD+ 1600),

3/8” (NCD+ 3200)

Storage Temperature (°C)

-5°C to 50°C (23°F - 122°F)

Operating Temperature (°C)

0°C to 40°C (32°F - 104°F)

IP Rating

20

Stud Placement Tolerances

+/- 0.010 (0.250 mm)

10.1 Specifications

10.1.1 Gun Dimensions

10.2 Accessories

Chucks

Part Number

Stud

Diameter, Ø

Chuck Size

Part Number

Stud

Diameter, Ø

Chuck Size

500-001-374

0.095

13 Ga.

500-001-366

0.190

#10 Thd./3/16”

500-001-363

0.109

12 Ga.

500-001-358

0.197

5 mm

500-001-355

0.112/0.118

#4 Thd./3 mm

500-001-362

0.236

6 mm

500-001-390

0.125

#5 Thd./1/8”

500-001-359

0.250

1/4"

500-001-356

0.134/0.138

10 Ga./#6 Thd.

500-001-360

0.312/0.315

5/16”/8 mm

500-001-361

0.157

4 mm

500-001-369

0.375

3/8”

500-001-357

0.164

#8 Thd.

500-001-506

0.394

10 mm

500-001-372

0.172

3/16 Annular Ring

(Navy Pin)

Stud Stop Pin Assembly

Part Number

Stud Length

500-017-017

1/4" - 5/8”

500-017-018

3/4” - 1-1/8”

500-017-019

1-1/4” - 1-5/8”

500-017-020

1-3/4” - 2-1/8”

Figure 10.2 Stud Stop Pin Assembly

11 Contact Information

North America Sales Offices and Warehouses

*Chicago

18601 Graphic Court Tinley Park, IL 60477

708.430.3770

Phone: 800.635.9353 Fax: 708.430.3975

*Philadelphia

260 Boot Road Downingtown, PA 19335 Phone: 610.873.0012

800.635.9353 Fax: 610.873.2550

**Elyria

7900 West Ridge Road P.O. Box 4019 Elyria, OH 44036-2019

Phone: 440.329.0400 Fax: 440.329.0521

*Westlake

821 Sharon Drive Westlake, OH 44145 Phone: 440.250.9242

*Dallas

2211 Century Center Blvd. Suite 105 Irving, TX 75062 Phone: 972.721.9055

800.635.9353 Fax: 972.438.7883

*San Francisco

23765 Foley Street Hayward, CA 94545

510.293.0660

Phone: 800.635.9353 Fax: 510.293.0677

*Toronto

6199A Danville Rd. Mississauga, Ontario Canada L5T 2H7 Phone: 905.795.8277

800.635.9353

905.795.8275

*Los Angeles

20621B East Valley Blvd. Walnut, CA 91789-2731

Phone:

909.468.2105

800.635.9353

Fax: 909.468.2112

Subsidiaries

International

England | Nelson U.K. Ltd.

47-49 Edison Rd. Rabans Lane Ind’l Estate Aylesbury HP19 8TE, UK

Phone: 44.1296.433500 Fax: 44.1296.487930

Middle East & Europe | Nelson Germany

Postfach 40-20 58272 Gevelsberg Germany

Phone: 49.2332.661.0 Fax: 49.2332.661.165

France | Nelson Frances S.A.S. Z. 1 du Chemin Vert 8 rue de l’Angoumois F-95100 Argenteuil, France

Phone: 33.1.3411.9400 Fax: 33.1.3411.2033

Asia/Pacific | Nelson Germany

Postfach 40-20 58272 Gevelsberg Germany

Phone: +86-22-24990335 Fax: +86-22-24995663 World Wide Web: NelsonStudWelding.com E-mail: Nelson.Sales@NelsonStud.com

Germany | Nelson Germany

Mailing Address

Postfach 40-20 58272 Gevelsberg Germany

Shipping Address

Flurstrasse 7-19 58285 Gevelsberg Germany

Phone: 49.2332.661.0 Fax: 49.2332.661.165

Central & South America

P.O. Box 3990 Seminole, FL 33775 USA

Phone: 727.596.9600 Fax: 727.593.3494

For Distributors in specific areas call:

440.329.0400

General Offices

7900 West Ridge Rd. P.O. Box 4019 Elyria, OH 44036-2019 USA

Phone: 440.329.0400 Fax: 440.329.0597 World Wide Web: NelsonStudWelding.com

E-mail: Nelson.Sales@NelsonStud.com

Italy | Nelson Italy

Via Miraflores, 20 Nichelino, (TO) I-10042 Italy

Phone:39.011.6059238 Fax: 39.011.6059230

A Table of Weld Parameters

CONTACT METHOD

Requires Use of 8m Combo Extension Cable

Stud Size

Stud & Base Material

Plunge (mm)

Voltage

Spring Pressure

Capacitance

M3 (#6)

Carbon Steel

3

120

Max

54K

Stainless Steel

3

100

Max

54K

M4 (#8)

Carbon Steel

3

120

Min

54K

Stainless Steel

3

120

Max

54K

M5 (#10)

Carbon Steel

3

130

50%

54K

Stainless Steel

3

120

25%

54K

M6 (1/4”)

Carbon Steel

3

180

75%

54K

Stainless Steel

3

170

25%

54K

M8 (5/16”)

Carbon Steel

3

160

50%

90K

Stainless Steel

3

160

75%

90K

(3/8”)

Carbon Steel

3

180

50%

144K

 Weld parameters above were established as optimum for conditions in our lab.

Heavy base plate material was used for physical testing purposes. Local conditions and/or plate thickness differences may necessitate parameter adjustments.

 Weld parameters above were established without the use of 10% detergent

solution. If detergent solution is preferred, the amount of weld heat will generally have to be increased, i.e., increase voltage and/or reduce spring pressure.

 Aluminum alloy 3003 was used to set the above parameters. Other alloys may require

parameter adjustments.

 If settings are needed (or desired) other than those listed above, please consult your Nelson

representative.

B Spring Pressure Chart

The settings are only to be considered guide values under optimal welding conditions. The exact spring pressure setting should be determined in trial welds considering factors such as base material, thickness, surface quality, welding position, stud type, stud dimensions, etc.

SPRING PRESSURE CHART

MATERIAL

COMBINATION

STUD MATERIAL

Low Carbon Steel

Stainless Steel

Brass

Aluminum 1100

Aluminum 5356

SPRING PRESSURE (%)

WORKPIECE

Steel C ≤ 0.25

3 3 3 3 3 3 3 3 3 3 3 3 4 4

Steel plate, galvanized <25µm

3 3 3 4 4 3 3 3 4 4 3 3 4 4

Stainless Steel

3 3 3 3 3 3 3 3 3 3 3 3 4

Brass (no free machining

3 4 4 3 3 3 3 4

Copper

3 4 4 4 3 4 4 5

Aluminum 1100

3 5 3 5

Aluminum 5356

3 4 3 4

Aluminum 6061

3 4 3 4

Ø STUDS (mm)

3 4 5 6 8 3 4 5 6 8 3 4 5 6 8 3 4 5 6 8 3 4 5 6 8

Nelson NCD+ Instruction & Maintenance Manual

Specifications and Main Features

Frequently Asked Questions

User Manual