Installers and Inspectors Guide for CADWELD Electrical Connections ®
This handbook is designed to guide the person in the field with the installation and inspection of CADWELD® exothermic welds, including CADWELD® EXOLON and CADWELD® ONE SHOT styles. The parameters and criteria outlined in this manual are based on tests performed by ERICO, and on our years of experience using CADWELD materials in the field to develop exothermic technology.
Contents The CADWELD® Process ............................ 4 The CADWELD Connection ....................... 5 It’s Easy to Make CADWELD Connections ............................................... 6 CADWELD Quality Standards ................... 8 Specifications for CADWELD Connections ............................................... 8 CADWELD Mold Inspection ...................... 9 Inspection of CADWELD Connections General Indicators .............................. 10 Size ....................................
The CADWELD® Process Cover Mold Starting Material Crucible CADWELD Welding Material Steel Disk Tap Hole Weld Cavity Cable Ground Rod The CADWELD® process is a method of making electrical connections of copper to copper or copper to steel in which no outside source of heat or power is required. In this process, granular metals (granular copper oxide and aluminum) are dumped from a container into a graphite crucible and ignited.
The CADWELD® process is applicable to materials other than copper.
It’s Easy to Make CADWELD® Connections Detailed instructions and safety precautions are provided with every CADWELD® mold. You must read and understand all instructions before making a connection. 1. • Dry the mold and the conductors. • Clean the conductors. • Place cable ends in the mold. 2. • Close the handles to lock the mold. • Drop the metal disk into the mold. 6 www.erico.
3. • Dump the welding material into the mold. • Sprinkle the starting material over the welding material and onto the lip of the mold. 4. • Close the cover and ignite. • Open the mold after the metal solidifies. • Remove slag from mold before next connection. 5. • A completed CADWELD® connection. www.erico.
CADWELD® Quality Standards All CADWELD® materials are produced to high standards under stringent quality control. All CADWELD connections are designed and tested using CADWELD molds, welding materials, and accessories. In the absence of any standards, national or international, we cannot accurately predict the individual product standards of our competition, either known or unknown.
CADWELD® Mold Inspection Chip in mold parting face Disk seat worn Mold parting face smooth Mold parting face has erosion lines Tap hole well defined Chip in weld cavity Weld cavity well defined Cable opening worn Good Replace A CADWELD® mold is designed to last for an average of 50 connections. This will vary according to the care given the mold during use. Inspect the mold regularly.
Inspection of CADWELD® Connections General Indicators Proper inspection of a CADWELD® connection relies on the judgment of the field personnel. Look closely at the size, color, surface finish, and porosity of the connection. Following the guidelines below will assist in making meaningful inspections. Photographs of good, acceptable, and reject connections appear on pages 14 – 17. Size 1. No portion of the conductor within the confines of the weld should be exposed. 2.
Higher than normal Normal Minimum acceptable Type VS Higher than normal Normal Minimum acceptable Type GT Higher than normal Normal Minimum acceptable Type SS www.erico.
Inspection of CADWELD® Connections General Indicators (continued) Color The color of a CADWELD® connection is best seen after a light wire brushing of the connection. It should normally be gold to bronze in color. Occasionally, it may be silvery at the top. This silver color indicates “tin sweat” of the surface, a normal condition. A CADWELD connection to cast iron or galvanized surfaces is often silvery due to alloying with the metals.
Inspection of CADWELD® Connections Visual Inspection Photographic Guides Like all electrical connections, a visual inspection is no guarantee of performance. Crimped or bolted connections cannot be inspected visually, but CADWELD® connections can be visually inspected and provide an indication of the quality of the weld. Visual inspection is recommended as a practical minimum. Use the photographs on the following pages as a guide to visual inspection.
Inspection of CADWELD® Connections Photographic Guides Good. A solid weld with only minor surface imperfections. Acceptable. Fill is lower than normal, but still sufficient. Acceptable. A worn or incorrect mold was used, allowing leakage around conductor. The fill in this connection is sufficient to allow it as acceptable. Attention to mold is required prior to making next connection. 14 www.erico.
Acceptable. The presence of water/moisture in conductor strands or mold indicates that one or both were not properly dried. Although the riser is porous, the weld is solid. The degree of porosity is not sufficient to reject this connection. Reject. Extreme amounts of slag on surface are caused by welding material leaking past disk or complete lack of disk. Inspect the condition of mold disk seat and check disk positioning prior to making the next connection. Reject.
Inspection of CADWELD® Connections Photographic Guides (continued) Reject. Light carbon traces on cable and connection are evidence of oil on cable strands. Oily cables must be cleaned with safety solvent. Reject. Heavy carbon coating on cable and connection is evidence of large amounts of oil or grease on cable. Cable must be cleaned with safety solvent. 16 www.erico.
Reject. Fill too low. Weld cavity was not filled over cable strands. “Fins” indicate that the mold was not closed tightly due to incorrect mold, incorrectly adjusted handle clamp, or presence of foreign material in mold parting line. Before making the next connection, check the mold for each of the above. Reject. Fill too low. Weld cavity was not filled over cable strands. Absence of leakage indicates that welding material size was incorrect (too small) or thru conductor moved. www.erico.
Field Situation Guide Most field difficulties can be overcome by checking the following problems. Problem A The mold doesn’t close tightly. Check for: 1. Adjustment of handle clamps. 2. Cables out of round or bent. 3. Dirt or slag in mold parting line. 4. Correct cable size. NOTE: Use “C” clamp if necessary. Problem B The connection is covered with excessive slag. Check for: 1. Welding material leaking past the disk, caused by: (a) Chipped graphite at tap hole.
Problem D The connection is porous Check for: 1. Presence of moisture either in conductor or mold. Remedy: (a) Dry the conductor by wiping and heating. (b) Heat mold with torch (to above 212°F) or by igniting welding material in mold without any conductors, taking care to prevent burns from the hot material running out of the mold. NOTE: Do not use the second method of heating if the mold has wear plates. Check for: 2. Other contaminants (oil, insulation, etc.) present in conductors.
Field Situation Guide (continued) (b) Check to be sure gap is centered under tap hole. NOTE: In some cases, the run (thru) conductor must be cut and gapped. Follow instructions for same or use CADWELD® Heavy Duty molds. Problem F The welding material leaks around the conductor. Remedy: 1. Use packing material around the conductor after the mold is closed. 2. Use molds with wear plates (which also act as chill plates). 3. Check for the proper mold. Mold must be sized for the cable being welded. 4.
Remedy: (a) See Problem F. (b) See Problem G. (c) See Problem H. 4. Conductor movement. Problem J The riser is too high. Check for: 1. Use of proper welding material size (see mold tag). 2. Moisture in mold or conductor. Remedy: (a) See Problem D. Problem K The mold wears out quickly. (Molds should produce an average of 50 connections.) Remedy: 1. Use CADWELD® B-265 cable clamp for hard-drawn copper or DSA Copperweld®. 2. Clean the mold with a soft brush, clean cloth, or newspaper. DO NOT USE A WIRE BRUSH.
Field Situation Guide (continued) Problem M When welding to ductile iron or cast iron, the weld does not “stick” to the surface. Remedy: 1. Remove all coatings before cleaning. 2. Clean the surface with a rasp or grinder to bright metal. When grinding, use an ERICO-approved wheel only. 3. Clean the surface with a safety solvent after grinding or rasping. 4. Use CADWELD® XF-19 alloy welding material (orange cap).
Field Situation Guide for CADWELD® ONE SHOT Applications Below are typical field situations related to CADWELD® ONE SHOT connections. Problem A Weld does not “stick” to ground rod. Remedy: 1. Ground rod must be cleaned with a rasp to bright metal. All scale and/or other coating must be removed. Wire brushing will not suffice. Grease must be removed with a safety solvent before cleaning. 2. If conductors are moist, heat with a torch. Any carbon deposit from the flame must be removed.
WARNING ERICO products shall be installed and used only as indicated in ERICO’s product instruction sheets and training materials. Instruction sheets are available at www.erico.com and from your ERICO customer service representative. Improper installation, misuse, misapplication or other failure to completely follow ERICO’s instructions and warnings may cause product malfunction, property damage, serious bodily injury and death.
