Motor Issue

**Theberylbloke** · 26th December 2013, 01:10 AM

Evening All,

First up I hope you all had a good Christmas.

RayG. Actually I am not an industrial electrician. I am an electrical fitter/mechanic and employed with Ergon Energy, who are the electrical distribution company for 97% of Queensland. I connect new houses to the mains and put meters on switchboards, among other things. Connecting a new installation is not rocket science. Carry out a continuity test on the main earth and switchboard. Then an insulation test on the customers mains. Connect the power. Do a polarity test. Carry out a neutral integrity test. Test the meter. Test any RCDs present. Document the results as required by law. See that the documents are filed away for 7 years. I test the equipment before use and if required, after use as well. I'm sure that all of you who want to do your own electrical work do all the tests required and have all the equipment? and it's all in test, of course!

What happens beyond the switchboard stays beyond the switchboard. i.e. we don't inspect beyond the switchboard. Until.. faulty wiring or an appliance causes a shock.

Several sparky's I know have said that the day after inspections stopped beyond the switchboard, was the day quality of work went downhill in a big way.

I know very little about motor control, it's beyond my experience. I understand some of the basics, reducing inrush on startup, protection, phase imbalance problems. I won't be changing the bearings on the FP2LB motor, I'll give it a local bloke who really knows what he's doing. I have not changed a set of motor bearings in 35 years. Yes I have the gear to do the job. Would I want to replace the motor because I got it wrong? No. Likewise, for VFD questions I ring a local guy who knows the stuff inside and out. I know nothing about PLCs. Horses for courses. The electrical game is pretty broad.

Simon. That was a very serious error on the part of the crew who did the job. We are all human. However, a proper polarity test would have identified this problem at the time of connection. Such a test is mandatory. It's probable that the person who made the connection now has a different employer and a different line of work. Your premises are probably connected to three phase. If it were single phase you would have had a lot of problems from day one.

Chris. AS/NZ3000 has one section specifically devoted to testing of a new installation or part thereof. Being "suitably qualified" by itself does not cut it. There are tests to check that circuits are not cross wired to other circuits, clear of shorts between active and neutral active to earth with minimum resistance readings. Tests to ensure that switches are in the active conductor(s), that RCDs trip within the permitted time frames, loop impedance tests etc, etc.

What you say is somewhat true with regard to polarity. The need for correct polarity is driven by Australia's use of the "Multiple Earthed Neutral" system. Incorrect polarity can leave exposed metalwork on appliances at 240 volts. The earth is connected to the neutral link at the switchboard and will trip a circuit breaker in the case of a conductive chassis becoming live. The system helps protect equipment, less so people. The installation of RCDs helps the people.

Dean. Two hours to identify a faulty RCD??? When I connect a new house to supply I check the operation of any RCD on the switchboard. Technically, I am not required to, I could just leave them turned off and leave it to the sparky. I test probably 10 or more a week. It takes maybe 3 minutes plus the time to get the tester from the vehicle. The vast majority of RCDs pass testing. Some do not. Your sparky clearly does not do much domestic work. He is probably quite good at other stuff I have no clue about.

On the subject of RCDs, I recall they are meant to be tested, using the test button, every three months, who here does that??? If it won't trip from the test button it should be replaced!

Stuart. We get audited from time to time, probably about every two years or so. hmm... Been awhile... I must be due.

Ewan. Exactly my point.

So.. to my next question.....

Those of you who are unlicensed and/or unqualified and want to do you own work, are you prepared to accept full responsibility and complete accountabilty for your work if it goes wrong? This includes but is not limited to fire (on your property and subsequently not covered by insurance), shock (including deaths, possibly of your own family and or friends, including legal repercussions) and damaged equipment, for say, the next 20 years ?

Before you answer think about what your property is worth to you? your loved ones? your workshop? If you have not completed the proper testing with the proper equipment, then how do you know it's correct & safe? If you can't answer this question with a wholehearted yes, you should not be working on your own electrical gear, licensed or not.

Cheers

The Beryl Bloke

**Theberylbloke** · 26th December 2013, 02:06 AM

Hi Aaron,

Not singling you out for special attention on purpose...

I had to edit my post above for legal reasons....

In about 2 or three years I will probably spend a day or two in court over an electric shock incident. For legal reasons I can't go much into this....

Let me suggest that you make this remark to any person who has had a loved one get a serious electrical shock or electrocuted. Particularly someone who was present when it happenned

I wish you well in such an endeavour. It probably won't go well for you.

I have recently been involved in investigating a serious shock. Perhaps you could have done the two days of paperwork or maybe you would like to stand in at court for me?

My work was not the cause of the shock, I was just part of the investigation.

Really this is what my posts boil down to... What is your life and that of your loved ones worth to you? The cost of getting a qualified person to do the job? Is that really how much those people, in your life, are worth to you?

Again Aaron I am not singling you out and I hope you will not be offended, my post applies equally to all those who would do their own electrical work. Rather it was better to reword and post this part of my previous message.

Cheers

The Beryl Bloke

**azzrock** · 26th December 2013, 05:24 AM

Hi BB. im not offended. Its good to have a frank discussion. I knew this was a testy subject. Are you saying that we
shouldn't attempt to fix our own plug in machines and equipment?
Sorry to hear about your accident.
I have received a electric shock. I was medevaced of a ship i was working on after one.
Ive done a few electrical courses at tafe and have a certificate of industrial electrical fault finding But im not an electrician.
I know my comment about electrical laws being about job security was a little over the top but i believe that the laws are not all about safety and in part have been manipulated to keep all the work in the electrical industry. Who can blame them they have a great cushy job. They wouldn't want to work hard like the rest of us.

I don't think i know as much as an electrician. how could i. But i have done the same courses at tafe. There is a lot of jobs at my place that remain on the "to do" list because im not a licensed electrification. Just because im not an electrician doesn't mean i would do unsafe work. Its unfortunant that
because of the laws we cant do simple electrical jobs around our own houses.
any way thanks for the comments. If we didn't live so far apart it would be great to talk about this over a coffee.
aaron

**Michael G** · 26th December 2013, 07:28 AM

BB - agree 100%

I work in the quality area of a company that does safety critical equipment. The thing that I try to impress on everyone is that if everything works properly then most people don't worry too much but if something goes wrong suddenly all that paperwork, the training and procedures/ standards become really important. While I'm occasionally accused of being heavy handed by suggesting that people could face jail time or financial ruin (while leaving any burdens of guilt to one side), the consequences of getting things wrong could indeed be that and paperwork, training and those procedures are all the defence they have.
We have engineers there that I trust implicitly to get it right but at the same time have a qualified engineer who I would not trust to do up his shoe laces properly. (Sadly, this person has recently been given responsibility for conducting all the RCD testing on site - can't work that one out, but no one asked me about this because they guessed what I would say). The idea that anyone (engineer or not) should be able to work on electrical wiring without specific training is not something that I would be prepared to support. Do a short electrical wiring & safety course and I'm not so worried but there is too much bad practice and poor information out there to rely on people "knowing". While most of it is simple stuff, that does not mean that it can not be done wrong.
I do do some occasional (post-plug) electrical stuff - mainly changing old plugs or cords but before I plug anything in it is checked against reference diagrams/ schematics and tested for continuity, polarity & shorting. I'm told you only get one go at life...

Michael

**A Duke** · 26th December 2013, 09:24 AM

The problem is like anything else, you don't know what you don't know. In other word the more you learn the more you discover there is to learn about it. It's all well and good for people who know what they are doing to do it but some of this would encourage any Dick Head who reads this forum to have a go and all types do visit here and some members are a bit doubtful some times.

Regards

**eskimo** · 26th December 2013, 09:33 AM

Originally Posted by Theberylbloke

On the subject of RCDs, I recall they are meant to be tested, using the test button, every three months, who here does that???

we sure do...swmbo and kids trip it regularly with the toaster

**simonl** · 28th December 2013, 11:18 AM

Originally Posted by eskimo

we sure do...swmbo and kids trip it regularly with the toaster

Mine gets tested every time I leave the extension lead out and it rains!

Sometimes it's at 1:00am when I'm on nightshift! oops!

Simon

**Oldneweng** · 28th December 2013, 12:15 PM

Our cows tested the shed RCD once. I had to shorten that lead some. The lead was in under cover but cows are nosy creatures. Funny thing was it took me ages to find it because I was chasing everywhere trying to find the fault. I did not look at this cord because it had been turned off. Still tripped tho!

Dean

**Ueee** · 28th December 2013, 12:28 PM

Originally Posted by Oldneweng

Our cows tested the shed RCD once. I had to shorten that lead some. The lead was in under cover but cows are nosy creatures. Funny thing was it took me ages to find it because I was chasing everywhere trying to find the fault. I did not look at this cord because it had been turned off. Still tripped tho!

Dean

That comes back to what Chris was talking about, in most cases only the active is switched. Any leak from the neutral will be picked up and trip the RCD.

Ew

**Oldneweng** · 28th December 2013, 04:39 PM

Originally Posted by Ueee

That comes back to what Chris was talking about, in most cases only the active is switched. Any leak from the neutral will be picked up and trip the RCD.

Ew

My thoughts exactly, but I could not work out how to put it. I started typing it but deleted when I ran out of suitable words.

I did ask the resident sparky at work and he said what you have stated.

Maybe if it had still been switched on the cows would have learnt a lesson. Too much to hope for tho.

Dean

**eskimo** · 29th December 2013, 10:14 AM

Originally Posted by Ueee

That comes back to what Chris was talking about, in most cases only the active is switched. Any leak from the neutral will be picked up and trip the RCD.

Ew

I didnt think we used voltage base ELCB's

I thought they were current based so as to eliminate false tripping...or have I got that ass up?

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