COMPRESSION CONNECTOR CRIMPING GUIDELINES
To retain UL or CSA rating, installation tools and methods must be matched to the connectors used
should be followed to maintain the UL and/or CSA rating for the completed connection. Connector manufacturers will often be in a position to specify several equivalent UL/CSA crimping recommendations for a specific connector installation. For con- nectors from No. 22 AWG through No. 10 AWG the compres- sion tools most often have mechanical operation. For No. 8 AWG through 4/0 AWG, the compression tools could use either mechanical or hydraulic means to apply the crimping force. Historically at 250 kcmil and above in wire size, the crimping force was almost always applied by a hydraulic crimping tool. With the advent of the TDM500, that has changed to 500kcmil due to the extra available leverage generated by the extendable handles. Mechanical tools for small wire sizes are generally single leverage types, while those for the medium sized cables apply the crimping force via a compound leverage system. Mechanical crimping tools make either a surrounding type of crimp (Fig. 1A) or a nest and indentor crimp shape (Fig. 1B). The hydraulic crimping tools used for the medium and large cable sizes can have quite a variety of crimping die systems and hydraulic pressure sources. Die-type Crimpers The die-type tools require that a separate set of inserts be placed into the crimping tool head for each different size and type (AL or CU) of connector that is to be crimped. These crimping die inserts are shaped to compress their specific con- nector size the correct amount when the full force of the hy- draulic system of the tool is applied to them. Die type crimping tools generally produce crimps that surround the barrel of the connector with either a rounded oval or a hexagonally shaped outer surface. Many of the copper and aluminum connectors used in the electrical contracting industry have a color code applied to them which matches up with a crimping die reference of the same color. This color code is meant to allow the installer to be able to find the correct die more quickly from as many as
Of all the methods used to make electrical connections, compression of the connector onto the cable with some type of compression tool is considered by most installers to be the most permanent of the common connection methods. To maintain Underwriters Laboratories (UL) or Canadian Standards Association (CSA) for a completed compression connection, it is necessary to use the installation tools and installation methods which have been qualified for the con- nectors by those organizations during the listing/certification processes. Cable Preparation It is imperative that the cable strands and the compression connector be clean and free of dirt and/or corrossion. This is particularly important when making connections on cables which have been installed for a period of time. Connectors which are Underwriters Laboratories Listed or Canadian Standards Association Certified may contain instal- lation instructions in the connector carton which may include information such as usable cable types, insulation strip lengths, and crimping tools for specific connectors. Proper preparation of the cable can make the difference between a permanent connection and a connection which may require a service call at some point in the future. The cable material will dictate the type of connector which can be used in the compression connection. Copper cable can be installed in a copper compression connector which has a “CU” rating or in an aluminum compression connector which has a “AL9CU” rating. Aluminum cable on the other hand, can ONLY be installed in an aluminum compression connector which has a rating of “AL” or “AL9CU”. ALUMI- NUM CABLE CAN NEVER BE INSTALLED IN A COPPER COMPRESSION CONNECTOR. Once the cable preparation has been accomplished and the proper type and size of compression connector has been selected, the connector manufacturer’s recommendations for choice of compression tooling and compression methods
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