timer on house trips safety switch quite often

[the grinch]

We had an electrician in this years or should say last year to put another line of power points under the eaves plus a analogue timer and separate circuit breaker or safety switch . problem is that when the timer is activated at 8:30 PM to start lightshow it is a 50 % chance that it will trip safety switch I dont believe we are running too much off that circuit am curious to why.? all lighting etc is all safe no shorts etc etc . has been a pain in the butt and really defeat s the purpose of having a timer as need to be present each night to ensure show starts . Electrician is on holidays and don't want to bother him just yet plus another callout may empty my wallet even further ! . just wondering if anyone has had same sort of experience . My gut feeling is that the sudden influx or surge of power is the culprit and have noticed on warmer nights seems to be ok more resistance due to heat ? Slowing the current ? Can anyone advise please is there any test can be performed or do I need something etc etc thanks in advance


Timer is hager eh010 model 230v 24std 16A


Safety switch is hpm rcbo 3ka 20 A

 

[lithgowlights]

Surge current from the volume of PSU's on the circuit?

 

[i13]

Reduce the number of power supplies on each timer. Each one has an inrush current when first turned on.

 

[lithgowlights]

I have 1-3 PSU's in boxes and thats not been an issue, but if I turn 2 boxes on at the same time it trips the circuit breaker most of the time

 

[fasteddy]

When power supplies are powered up then there is what is called inrush current, this is the current needed to saturate the induction coils within the power supplies and only lasts a split second but can be enough to trip the CB due to overcurrent.
There are different ways to get around this. Either use additional timers that come on at separate times to the reduce the amount of inrush current on the circuit or else investigate a Class C or D circuit breaker that is designed for use with high inrush current applications as these have a longer trip curve. Fuses are also better at handling inrush currents


A brief explanation of the 3 main classes of Circuit Breakers


•Type B MCB
•Type C MCB
•Type D MCB


Type B MCB:

This type of MCB trips between 3 and 5 times full load current. Type B devices are mainly used in residential applications or light commercial applications where connected loads are primarily lighting fixtures, domestic appliances with mainly resistive elements. The surge current levels in such cases are relatively low.

Type C MCB:

This type of MCB trips between 5 and 10 times full load current. This is used in commercial or industrial type of applications where there could be chances of higher values of short circuit currents in the circuit. The connected loads are mainly inductive in nature (e.g. induction motors) or fluorescent lighting.

Type D MCB:

This type of MCB trips between 10 and 20 times full load current. These MCBs are use in specialty industrial / commercial uses where current inrush can be very high. Examples include transformers or X-ray machines, large winding motors etc.


All the above three types of MCBs provide tripping protection within one tenth of a second.

 

[bjpc2716]

good one eddy aka northen zop

 

[David_AVD]

I switch 8 Mean Well power supplies (all are in the 150W - 320W range) on together and they are all on the same circuit. I've not had a single trip.

One thing that I couldn't see mentioned was when the breaker trips, was the red flag showing (earth leakage) or not (over current).

 

[fasteddy]

The other thing is that the CB may be actually faulty and trips way lower than it should, Ive seen that before as well.

 

[St Gabriel]

The grinch - Is the RCD or MCB side tripping? Not sure whether the MCB side can trip from overcurrent or if the RCD side will disconnect to protect the circuit. My suggestion would be, drop a part of the load to see if you can get it to trip. Process of elimination, if it still trips with reduced load, then would suspect faulty powersupply, try isolating different ones to narrow down the culprit. Failing all that, best bet would be to (get the electrician to) test the RCD to ensure there isnt nuisance tripping.

Fasteddy - I believe the HPM RCBO is a "c" curve breaker and believe "b" curve are primarily used for protecting delicate electronics. I have never seen one "in the wild". At least in NZ, normally have c curve and only use d curve for commercial work when supplying motors that have to start with full loading on them (pumps/conveyors/welders).

Also "POP", suppose i better go and introduce myself in noob section

 

[fasteddy]

Fasteddy - I believe the HPM RCBO is a "c" curve breaker and believe "b" curve are primarily used for protecting delicate electronics. I have never seen one "in the wild". At least in NZ, normally have c curve and only use d curve for commercial work when supplying motors that have to start with full loading on them (pumps/conveyors/welders).

Also "POP", suppose i better go and introduce myself in noob section

You are correct that most circuit breakers I have seen used in domestic applications are C type but my experience is more in the industrial arena where we would use D type or fuses for motors and transformers to overcome nuisance tripping. The descriptions of the CB types was taken from a CB type description link and may in fact be more related to US standards because C type seems to be the predominant type uses here in Australia for domestic use.

But if he using the cheap Ray Wu power supplies then there is a good chance its tripping the RCD part of the CB as the Ray Wu power supplies can tend to leak a bit of current.

 

[scamper]

I agree with all of the above.
The only thing i can add is that I had the same problem for a couple days here.
It turned out that my fridge was on the same breaker, so the first time i noticed it was when we just got home from shopping and the wife had the fridge open for an extended period and then I turned on the lights.
When I realised what was going on, I just relocated a few items to a different circuit and never had the problem again.

 

[fasteddy]

Fridges are renowned for causing accumulated RCD trips and is a big reason why they have their own circuit in modern houses

 

[scamper]

Fridges are renowned for causing accumulated RCD trips and is a big reason why they have their own circuit in modern houses

I spend way too much on xmas lights to able to afford a modern house

 

[the grinch]

Hey guys thanks so much for the info it is the hpm rcbo that trips and no fridge in that circuit is separate line of power for light show only. Im starting to get little bit confused but am thinking is not suitable type of circuit breaker for our type of purpose due to the psu s . So my next question is which type shall I recommend to the electrician as he seems to be purely domestic tradey and didn't understand our needs but is great guy and sure will be happy to help sort . And yes we decided finnally after many years of having ext cords running through windows etc etc and remember one year in particular couldnt boil kettle plus microwave as would trip whole house lol so at least when does trip now doesn't take whole house out now. So yes im thinking needs different circuit breaker but what type will be best for our needs thanks guys

 

[djgra79]

I never have tripped a circuit but the TV in the lounge used to flicker previously. This year I got a double GPO placed on left side of house. I've also cut back on AC elements and only have 4 PSUs to turn on, so I think a combination of sharing the load across circuits, plus lowering the AC load has helped me this year.