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Glossary of terms you will come across during your Phase 2 training.

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From the QME website:

QME is a world leader in supplying services to the mining industry. QME supply new and re-manufactured underground and open pit mining equipment. to the mining industry world wide. Our aim is to supply a customer service of reliability and satisfaction.

Our 15,000 ft2 rebuild facility is located on the east coast of Ireland near Navan, Co. Meath and has been in operation since 1985. Throughout this time Quarry & Mining Equipment Ltd. has built a solid reputation for top-quality standards in remanufacturing and customer support.


Contact name is John Murnin.


  • Landline: 046 9073 709
  • Mobile: 087 4191 014
  • Address: Coolfore Road, Ardbraccan, Navan, Co. Meath

Apprentices (Note: we have only begun recording apprentice names here since July 2012, cp12b, so there may be others who attended prior to that date and are not listed here)


In construction plant fitting, there are 2 contexts for quenching:

  1. Diesel Fuel Injection- where we quench metals that have been heated
  2. Electrics and Electronics - where we use a diode to reduce or eliminate a voltage spike every time we reduce or open the 86/85 circuit of a relay

In Diesel Fuel Injection:

To quench a flame means to put it out. For example, you would use a fire extinguisher to quench a fire.

In the context of combustion in an engine, quenching means that when atomised fuel enters a cold engine, the low temperatures cause the atomised fuel particles to condense on the relatively cool cylinder walls.

As we know, the only part of any fuel that burns is the vapour, so fuel that has condensed on to a cold cylinder wall does not produce vapour and will not burn.

The areas around cylinder walls are known as quenching zones, and any fuel in these zones will not burn. On the exhaust stroke, this unburnt fuel is expelled from the engine as HC (hydrocarbon).

In Electrics and Electronics:

We use electromagnetic relays in automotive circuits. They have 2 circuits inside: 86/85 and 30/87

The 86/85 circuit is essentially a coil of wire which we energise to make an electromagnet. We then use this magnet to close the contacts in the 30/87 circuit, causing the relay to close the circuit it serves.

Relay schematic showing details of quenching or clamping diode.Because 86/85 is a coil of wire, every time we open the circuit, the magnetic field around the coil of wire will collapse and induce a voltage spike. In order to prevent that spike from damaging any electronics in the circuit, we fit a diode across the 86/85 contacts. There are many names for this diode, and one of them is a 'quenching diode'.

Other names include fly-back, snubber and clamping diode. Follow the automated glossary links for more information on clamping diodes.


You will come across this term when dealing with linear voltage regulators, and you read their data sheets.

Quiescent current is the current drawn by a circuit when it is not amplifying a signal or driving a load.

You can think of it as the baseline current required to have the device ready to perform its task.

Please note, if you want to contact the main Training Centre in Baldoyle, you need to ring 01-8167400.

If you want to contact the CP Fitters' Section, you can Contact Us by email,, or by telephone: 00 353 1 8167543 This number gets you through to the CP Fitters' Section, Baldoyle Satellite Unit.

Our Address is : Construction Plant Fitters' Section, Unit 116, Grange Way, Baldoyle Industrial Estate, Baldoyle, Dublin D13 CA48.
We operate in a satellite unit which is about 300 metres away from the main training centre. You can see the location of this unit here, in Google Maps. You can also Check here for directions to the Baldoyle Training Centre.

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