There are different types and sizes of wire terminals, but the procedure for installing all of them is the same. The objective of this procedure is to show you how to correctly strip an electrical wire and connect a solderless terminal.
Part 1. Preparation and safety
- Correctly strip an electrical wire and connect a solderless terminal.
Whenever you perform a task in the workshop you must use personal protective clothing and equipment that is appropriate for the task and which conforms to your local safety regulations and policies. Among other items, this may include:
- Work clothing - such as coveralls and steel-capped footwear
- Eye protection - such as safety glasses and face masks
- Ear protection - such as earmuffs and earplugs
- Hand protection - such as rubber gloves and barrier cream
- Respiratory equipment - such as face masks and valved respirators
If you are not certain what is appropriate or required, ask your supervisor.
- Wire stripping pliers have sharp edges and require a tight grip. Do not trap your skin between the jaws; otherwise you risk a severe cut.
- When removing the insulation from wire, push away from you rather than towards you.
- Make sure that you understand and observe all legislative and personal safety procedures when carrying out the following tasks. If you are unsure of what these are, ask your supervisor.
Points to note
- Solderless terminals require a clean, tight connection. So make sure the wire and the connection are clean before fitting any terminals.
- Use connections that match the size of the wire.
- Do not use side cutters, pliers or a knife to strip the wire. Using these tools will damage some of the wire strands and may break the wire inside the insulation.
- To keep the wires together after stripping them, give them a slight twist. Do not twist the wire too much; otherwise you risk a poor wire-to-terminal connection.
- Use the correct crimping tool for the connection. Using the wrong type of tool will cause the connection to have a poor grip on the wire.
Part 2: Step-by-step instruction
- Select the terminal
There are different types and sizes of wire terminals, but the procedure for installing all of them is the same. This is a bullet type of crimp terminal. Make sure you have the correct size of terminal for the wire to be terminated, and that the terminal has the correct volt/amp rating for the job it is to perform.
- Strip the wire
Remove an appropriate amount of the protective insulation from the wire. Always use a proper stripping tool that is in good condition.
- Place the terminal on the wire
You will get a better connection if you do not twist the strands together tightly before placing them through the terminal, as this gives the terminal more surface area to come in contact with the wires when crimped. However, it can be difficult to insert the wires into the terminal if they are all just loose strands, so twist them together just enough to help you insert them cleanly. Place the bullet or terminal onto the wire. It is important that the stripped part of the wire does not extend beyond the insulated part of the terminal.
- Use an alternative terminal
Some types of crimp terminals do not have an insulation component fixed to them. These come in two parts and the insulator is supplied as a separate component. In these cases, always make sure that the ‘core’ of the wire to be crimped extends through the ‘core wings’ in the terminal.
- Select the crimping anvil
Use a proper crimping tool for pin or core crimping. DO NOT use pliers as they have a tendency to cut through the connection, which can give trouble during service. Select the proper anvil for the connector or terminal selected. These are usually color-coded so it is easy to match the terminal with the right size anvil.
- Crimp the terminal
Crimp the ‘core’ section first. Use firm pressure so that a good electrical contact will be made, but not excessive force as this can bend the pin or terminal. Then crimp the insulation wings or section. This crimp is on the wire insulation to hold the cable in place, not for electrical contact, so you do not need to crimp this section quite as hard. Give a gentle tug on the finished job to ensure that the connection will hold in service.