Short Circuit Of Cove Lightings

[quarkz 2]

Hi,

After I moved in to my resale, I realised that my cove lightings will short circuit sometimes. However, this was left behind by the previous owner. My ID's electrician told me to change all the original 10 T8 tubes to T5 to solve the problem. He said that maybe one of the T8 is damaged.

However, it seems an overkill. Changing all T8 to T5 cost $200 - 400. Plus installation cost $150.

Is there a better way to check and diagnose the problem?

Thanks!

[Pelect 3]

It seems rather extreme to change all the tubes just to solve the problem. Worst is that after changing all the tubes, the problem might still be there. So best is to find out the root cause if possible.

However, to begin with, could you describe what happens when you say the lights will short circuit sometimes?

Do you mean the circuit breaker(s) trips or one of the tubes gets blown out?

How many lights are there in total and does one switch control all the lights?

If it is the fault of one particular ballast or tube, one thing I can think of is to remove one tube at a time and see whether the problem goes away.

[quarkz 2]

Thanks Pelect for your help.

Ya, the main circuit breaker trips and the whole house has no power, except for the bomb shelter. There are 10 T8 in total and 1 switch controls all lights.

I'm also thinking of removing 1 tube at a time to test. Is there other solutions?

[w7_lee 11]

Removing the tube to find the fault seems to be the best option (besides replacing all which will cost a few hundred dollars).

But you can try removing 5 tubes on the first go and leave 5 working. If it does not trip, then you know those 5 that was left running is fine. Then install another 1 or 2 tube each time until the CB trip.

If the first 5 tubes are remove and you get a trip, then you know (at least) 1 of those 5 tube (not remove) has a problem. Then you replace the 5 you remove the first time and start removing the others. Hope I'm not making it more confusing.

With that being said, I think the tubes are not the main problem. The ballast is likely the problem, the probably heat up and cause the trip. If the CB dont trip, the ballast might catch fire.

So you know you have a working CB.

You should be finding the faulty light assembly and replace the ballast of that assembly.

[Pelect 3]

Thanks Pelect for your help.

Ya, the main circuit breaker trips and the whole house has no power, except for the bomb shelter. There are 10 T8 in total and 1 switch controls all lights.

I'm also thinking of removing 1 tube at a time to test. Is there other solutions?

w7_lee has a good suggestion to remove 5 instead of 1 at a time.

If removing the tubes does not solve the problem, then you need to focus on the ballast and also check the wiring between ballast and end connectors. I wouldn't recommend to do this if you are not familiar with electricity. What you can do in this instance would be to see the ballast rating for all the tubes are the same and meant for the type of tube you are using. I'm not sure if ballast is prone to any earth leakage and it is more difficult to trouble-shoot if there is earth leakage. Regardless, until the issue is well understood, no point to change all the tubes and hope the problem will go away.

[quarkz 2]

Thanks Pelect and w7_lee,

Will try it and see how it goes!

[Pelect 3]

Keep us posted

By the way, please play safe and be safe.

Turn off the light circuit breaker and on/off switch when you remove the tubes.

Avoid touching any metal parts with your bare hands and wear a pair of thick rubber slippers.

Another question I have if you don't mind is, does this problem happen the minute you turn on the switch or it happens after a certain amount of time? I presume only the light MCB and main RCCB (the one with a button) trip and no other MCB trips. Correct me if I am wrong.

[quarkz 2]

Hi, sorry for the late update. Was busy with my baby ...

I tried to remove 1 side of the tubes (5 of them) and it still trips. However, after that I changed my on/off switch to a new one. Now with this change, no more tripping, even after I placed back all the tubes!

So I thought it was the switch's problem. But recently, it trip again when my wife went to switch off the light :-(

However, nowadays it happens rarely. Previously, it happened rather frequently. So now just use as normal, most likely the switch got some problem, but maybe somewhere else too ... but too lazy to check thoroughly..

[MrKangTeo 54]

Removing the tube to find the fault seems to be the best option (besides replacing all which will cost a few hundred dollars). But you can try removing 5 tubes on the first go and leave 5 working. If it does not trip, then you know those 5 that was left running is fine. Then install another 1 or 2 tube each time until the CB trip. If the first 5 tubes are remove and you get a trip, then you know (at least) 1 of those 5 tube (not remove) has a problem. Then you replace the 5 you remove the first time and start removing the others. Hope I'm not making it more confusing. With that being said, I think the tubes are not the main problem. The ballast is likely the problem, the probably heat up and cause the trip. If the CB dont trip, the ballast might catch fire. So you know you have a working CB. You should be finding the faulty light assembly and replace the ballast of that assembly.

This sounds like a good option indeed

[CharSiewPau 60]

This sounds like a good option indeed

Sounds like it boss