Sunday, 19 May 2019, 01:31 PM

Site: CP Fitters' Phase 2 Apprenticeship Training
Course: CP Fitters' Phase 2 Apprenticeship Training (CP Fitters Homepage)
Glossary: Course Glossary



The 3 effects of electicity.

3 Effects of electricity:

  1. Chemical change  - For example, the electrolyte in a battery changes from sulphuric acid (H2SO4) when the battery is charged, to water, H2O, when the battery is discharged.
  2. Heat - For example, current passed through a bulb causes the filament to glow white hot. This is incandescent heat.
  3. Magnetism - for example, when we pass electrical current through the commutator and the field windings of a motor, like poles come into close proximity. These poles repel each other, giving us the motoring action.

DIN numerical wiring code:

  • 15: Battery live supply controlled by the ignition switch (often referred to as 'live under key').
  • 30: Battery live or battery positive (+)
  • 31: Battery earth or Ground (-)

Other codes you will come across on Phase 2 training include:

  • 85: End of coil (for example, the end of the coil windings on an electromagnetic relay)
  • 86: Start of coil (for example, the start of the coil windings on an electromagnetic relay)
  • 87: To load (for example, on an electromagnetic relay, battery positive is supplied to terminal 30 on the relay. That leads to a set of contact points, and the far side of those contacts is terminal 87, which leads to whatever load the relay is serving.

Understanding European DIN Codes (PDF document download)

Injector clamping boltInjector clamp bolt.



Also written as 50 Hz or 50Hz.

This is the frequency at which mains electricity in Ireland is delivered at.

We know that in an AC circuit, rather than flow constantly in one direction, the electrons move rapidly back and forth. The rate at which these electrons move back and forth is referred to as the frequency of the supply. In Ireland, the mains AC supply has a frequency of 50 Hz. In other words, the electrons in our homes move back and forth in the wires 50 times every second when a circuit is closed.


From Wikipedia:

555 chipThe 555 Timer IC is an integrated circuit (chip) implementing a variety of timer and multivibrator applications. The IC was designed by Hans R. Camenzind in 1970 and brought to market in 1971 by Signetics (later acquired by Philips). The original name was the SE555 (metal can)/NE555 (plastic DIP) and the part was described as "The IC Time Machine". It has been claimed that the 555 gets its name from the three 5-kohm resistors used in typical early implementations, but Hanz Camenzind has stated that the number was arbitrary. The part is still in wide use, thanks to its ease of use, low price and good stability. Read more...



A4 lever arch folderThis is a hard covered folder for holding any course notes you may write up, and for any diagrams you may draw.

It is important to get into the habit of writing up your notes on a regular basis. To that end, you are supplied with a spiral notebook and black and red pens. During induction, you will also purchase a geometry set and a pack of markers.


A4 refill padsDuring your phase 2 training, it is important that you take and write good notes on the course material. You should also get used to drawing detailed diagrams of vehicle and machine components.

In order to help you do this, you will be issued, free of charge, a spiral notebook and an A4 refill pad. As you fill these pads and notebooks, you will be given new replacement items, also free of charge.


Advanced Automotive Engineer.

This is a qualification awarded by the Institute of the Motor Industry.


Anti blockier system, or anti-lock braking system, an electronically controlled system that senses the relative speeds of road wheels in order to determine whether braking wheels have locked up and began to skid. If they have, the system overrides the braking effort supplied by the driver, and frees the brakes until the wheel begins to turn again (stop skidding).

The system is informed by speed sensors at the wheels. These same sensors can be used to feed into a traction control system.

Check here for more information.


Acceleration is simply a change in speed.

Acceleration can be positive - an object speeds up, or it can be negative - an object slows down.

The kind of acceleration we all experience every day is the acceleration produced by gravity - 9.81m/s2, referred to as 'g' in engineering calculations.

For example, in order to calculate the weight of an object, we multiply its mass by the acceleration produced by gravity: