Electrician Charges for Replacing

Hi all

I had an electrician come out last week for an AC circuit board tripping issue.
He charged me $80 to upgrade the 25A breaker to 32A. The issue wasn’t fixed and I had AC technician come in and they confirmed that everything seems to be ok on the compressor.
After the upgrade, surprisingly when I turn on the AC, it directly trips the RCD(and not the AC breaker).. the AC Technician believes this could be due to neutral to earth wiring issue(or something like that) and advised me to get the electrician again to have a look.

When I called the electrician again, he advised me to have a RCD only for the aircon, so that any issues in future with the ducted aircon will trip the standalone RCD for Aircon and not the entire house.

He said he would charge me $150 in total to replace the 25A aircon breaker with 32A breaker and have a RCD for itself. Is this reasonable ?

Also, does it make sense and are we heading in the right direction ?

Thanks in advance

Comments

  • +13 votes

    Okay I'm no sparky or with any qualifications in electronics or electrical engineering, but to me upgrading a circuit breaker from a 25amp to a 32amp when it used to work fine on the 25amp is stupid. Something is drawing to many amps.

    And now it's tripping the RCD, so that means there is some sort of earthing issue, so something is broken. Either a cable, or something in the motor itself.

    I do think it is good to have the ducted air-con on its own RCD. But frankly you need to find why the AC is tripping the RCD before something either catches fire or someone is electrocuted.

    • +1 vote

      If something is tripping, the problem has to be the tripping. The logical conclusion is to make the tripping stop by stopping the tripping.

      To be a fine electrician, first you must think like an electron.

    •  

      Well there was some problem when it was on 25A, the difference was it used trip only the aircon breaker… but after the upgrade to 32A, it’s tripping the RCD

  • +2 votes

    Any tradie call out fee these days for $150 incl the part is par for the course.

  • +1 vote

    An aircon (especially a ducted aircon) should be on it's own RCD. I wouldn't be surprised if for 10-15 years, it's been uncompliant not to as per the Australian Standards.

    •  

      Ah right, this is about 15 years old house and the ducted AC has been installed by the builder.
      Probably that’s the reason it’s not on its own RCD

      •  

        I'm just the mech eng at my work but listening to the elec engs voodoo talk, they claim that RCDs "wear out". When they do this they generally trip prematurely. I'm assuming they have dumbed this down for my benefit.

        We do a push button test every 6 months (just whoever is onsite) and an operating trip time test (by a sparky) every 12 months (harsh environment).

        Maybe while he's in there, get the old RCD trip time tested or just change the whole row if it's a simple board.

        RCDs are $25-$50 each.
        CBs are $5-$25

        Is the sparky doing any actual diagnosis with a meter / test set or just working on years & years of experience (guessing)?

  • +2 votes

    if an airon is causing the breaker to go at 25 amps, why would it fix the problem upgrading it to 32 amps, makes no sense, looks like you need a new different electrician.

    •  

      What he said was it might be pulling more load when turning on or off(a bit more than 25A) and hence he suggested to upgrade to 32 A

      On the other had, I had the capacitor(the previous one looked faulty) replaced after the upgrade and it did run for few days before starting to trip the RCD whenever it’s turned on

  •  

    How big is this ducted system mate (kw)?

    •  

      11.9

      •  

        Should be on a 40amp RCD mate. Max amperage draw will be around 40amp, if I'm not mistaken. In addition, I'm starting to think that your wiring isn't thick enough to meet the power draw either. May need to be upgraded.

        • +1 vote

          Yes the current RCD is 40amp, and aircon is 32amp(previously 25amp)

          •  

            @spk: Usually, for an aircon system, it will always display the output power, which is 11.9Kw as mentioned.
            To find out the exact breaker size it would need, is decided by the input wattage, then converted to current.
            you would usually find that it will only run at about 12 to 15A, but 25A would be plently. only time it would use heavily is when you use it at heat mode max temp and max fan, or really hot summer at lowest temp with max fan, having the compressor facing at direct sunlight (usually north/west)

            Anyhow going back to the problem, if the ac has been running from a 25A RCD/circuit breaker/RCBO/MCB, for many years, you should not have a problem with over current, and especially when you had it replaced with an 32A circuit breaker.

            The first step is just to find out the problem of the circuit, which is replacing your old RCD.
            But depending on which state you are in, i know that in QLD, you cant use RCD, or a normal circuit breaker on ac circuit anymore (since 2018), instead you will to use RCBO.

            then
            the electrician should test your cables if this is the cause of the problem.

            if problems persist then,
            Double check if you still have warranty, because usually manufactures, ie Mitsubishi heavy/electric come out to fix/replace for free.

            if not then

            call a refrigeration guy or a person who has both licences in the trade. they should check on all the operation of the compressor to your condenser, ie refrigerant gas levels, fan and motor is working. (generally cost around $180/call out, and $1000 or more to replace motors, fans, re-gassing)

            if not then

            you would probably need to replace the system.

            I hope this will help.

  •  

    I think you've got your answer, but just wanted to let you know the current norm is to wire each circuit on a combo circuit breaker/rcd. And for things like ovens that dont use an RCD, just a circuit breaker.

    •  

      The current norm is all circuits must be installed on an RCD. This includes ovens, ACs, everything. For commercial you don't need an RCD if the appliance is more than 32A.

  •  

    I'm not a sparkie but if you have put the AC on it's own RCD it's still going to trip that RCD (ie this is not going to fix your problem).

    I would not get in the first electrician again, he doesn't sound like he knows what he is doing. It should be really simple to lookup how much power the AC draws, and if it has only started recently tripping then putting a bigger breaker on it was never going to fix the problem. He just wanted to do something so he could justify charging you for a callout.

  •  

    What the book that came with it say.
    Should have a wireing manual for sparkies

  •  

    You should still be able to get info for older models online.
    Or ring support what brand is it.

  • +1 vote

    Firstly, I'm a dual trade Electrician / Refrigeration Mechanic in Brisbane.

    A lot of people here are on the right track. If it worked fine for many years at 25A it shouldn't of needed an upgrade. Especially since you still have a problem.

    If I assume correctly the circuit breaker was tripping before the upgrade, now after the RCD is tripping. This doesn't make much sense, but really comes down to what the electrician did in the board.

    Now before you go hiring anyone make sure they hold a contractors license and they are insured.

    The first step would be to determine what the fault is. This could be identified through some simple insulation resistance and continuity testing.

    Second would be to repair. Could be as simple as bad wiring or overloading of RCD.

    However it could also be a faulty compressor. If internal windings start breaking down this can cause excess current and Earth leakage in the presence of moisture.

    $80 is a steal for the first bloke, but I wouldn't have him back unless he tests first. He also must provide a test sheet on completion.

    Let me know if there's anything else.

    •  

      Hi mate

      Thanks for your response.

      I’ve got the compressor tested twice(with multimeters etc.) and the results were ok. The AC does its job when it’s on - both cooling and heating, so I’m convinced it’s not an Aircon fault.

      I’ve got the same AC technician to have a look at the circuit board and he demonstrated me how the wirings were loose across the board. All the circuits are loose as well. I was surprised by the way he shook the wires slightly and the RCD tripped instantly.

      He wasn’t comfortable fixing them as he wasn’t an electrician. So,I’ve got another electrician yesterday to fix it and he fixed all the bad wiring, tightened all the circuits, replaced the RCD(as he believes it could be faulty). Also, recommended to get the main circuit(100Amp) replaced.

      It’s a shame the first electrician couldn’t pick up this simple cause.

      I’m currently testing with variable loads to see how it goes. As many of others suggested, I’d get the AC circuit connected to a RCD of its own.
      Hopefully this would be the end of it.

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