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rootsy
19-06-2008, 04:04 PM
Hi Guys,

Does anyone have any advice or tips for electrical fault finding on a/c units etc. For exmaple testing a LP switch or a solenoid. (This has always been my weak point and you cant rely on fault codes all the time.) Any advice wouldbe appreciated.

frank
19-06-2008, 07:40 PM
Hi Rootsy

Your profile says that you are a Service Engineer, yet you post a rookie question?

Are you just learning the trade?

rootsy
19-06-2008, 07:50 PM
Yes, learning the trade. The guys I work with dont really explain the ins and outs etc and i would rather know what to be looking for instead of phoning technical. I started off doing very little a/c when i registered thats why I probably put service engineer. I've been doing installation since, but want to get in to a service role. I understand basic electrics etc but want to be able to fault find from scratch and need pushing in the right direction.

frank
19-06-2008, 08:49 PM
Thanks for being honest.

Electrical fault finding is easy - for anyone who knows how to do it ;)

As with anything, it takes time.

Most large fridge or A/C systems consist of two types of electrical circuit.

The power side and the control side. The control side tells the power side when to apply power, usually through contactors or relays but not always.

The best advice I can give you at the moment, without being too technical and losing you in the mist is to get hold of some mechanical wiring diagrams (simple ones without electronics) and try to trace the path of the current from where it enters the drawing to where it ends up at the contactor/compressor.

Spend a few moments studying the electrical drawings inside the covers of the equipment you currently work on.

And don't forget - ask lots of questions.

bernard
19-06-2008, 09:25 PM
Hi

The first lesson is ask ask ask,I,ve lost count of how many times I,ve ask what others think is a silly question but out of the ten people who laugh probally only two know the answer.Once you loose the fear of asking then you will learn fast.I have in the past postlinks to simple electrically tests but can,t find them a the mo.

I did find one but there is better.

http://www.tigoe.net/pcomp/code/understanding-electricity

Good Luck

Bernard

icecube51
19-06-2008, 09:49 PM
if you don't find it straight away, go back to basics.
do the elimination route, switch everything of ,and switch it on one by one,you see witch one is foulty,and change or repair it.

Ice

lewies548
01-07-2008, 12:46 PM
One of the keys to elimination is having tools which will help such as coil magnets which operate SOLINOIDES IN PLACE OF THE coils, the insulated screwdriver placed in a solinoide whole to check current flowing (WILL FEEL THE MAGNATISM), ie that part of the circuit FUNCTIONS UP TO THERE), multi meter test for voltage, voltage detection sticks which glow. a DRAWING WORKS AS WELL TO FOLLOW.You dont have to buy the dearest just look at them and rememer NOT TO SHAKE HANDS WITH THE NATIONAL GRID IT HURTS LOTS N CAN KILL:confused: IF UNTRAINED AND Incompetent

superswill
01-07-2008, 08:27 PM
Hi Guys,

Does anyone have any advice or tips for electrical fault finding on a/c units etc. For exmaple testing a LP switch or a solenoid. (This has always been my weak point and you cant rely on fault codes all the time.) Any advice wouldbe appreciated.

as said its ask ask and ask,ive seen a few a courses pop up on this dont know if this will help you


http://www.ellistraining.com/coursedates.htm

other training providers are available:

http://www.ior.org.uk/ior_/images/pdf/se/datasheet%20-%20training%20matrix.pdf