MH Ballast caught fire

[kadios]

Hi all,

I used an overhanging industrial 150watts MH which I got from those lighting shops along Kelantan Lane. I use a magnetic ballast which is placed outside of the lighting hood. Things were going fine for close to 2 yrs until a few weeks ago, the ballast caught fire all of a sudden. Fortunately, my mum was at home and put out the small fire. When I brought it to the shop, the shopkeeper said the capacitor has burnt and replaced it.

My initial guess is that there was probably some current surge or overvoltage which caused the degraded component to fail. The shocking and surprising concern is why my house circuit breaker did not trip when the device was malfunctioning. It only tripped after the device started burning.

Does any one encounter any safety problems with their MHs before?

Anybody has any idea on how to prevent such a recurrence again? The consequences are unthinkable my wooden tank cabinet catch fire. Any advice is greatly appreciated.

Cheers!

[tawauboy]

circuit breakers trip only when there is an overcurrent. elcb trips when the leakage current exceeds a preset limit. thus, for your case, the breakers will not trip.
you may need to check the housing (where the capacitor is) and ensure that it is well ventilated and the temperature kept as low as possible.
check the voltage rating of the capacitor and ensure that they are rated correctly.

[juggler]

Wow - sounds scary.

[ranmasatome]

Same thing happened for me when my Aircon caught fire from leaving it on for too long each day.. i used to use the aircon to cool all my tanks as they were in my room....but after the occurance... which is similar to your case where there was no trip in the circuit breakers..i changed to chillers...
The only difference is... no one was in my room when it happened.. people who know about it know the extent of the damage.. i lost a lot of things..

[shermans]

wah... dangerous....

[medicineman]

No good... I use the same type of light, six of them. Hope the thing will die peacefully instead of bursting into flame.

I've taken several precautions though :
- Placing the ballast out of the box, remotely so the whole set will run cooler.
- Replacing all the wiring with better quality ones.
- Mount the whole thing on metal bracket (so no wood to burn)
- Use only high quality connectors (believe me this one almost got me killed from electrocution, right from the tank's water).

[vinz]

I think when we buy electrical appliances, especially those that run without supervision for long hours, we have to be extra careful. Some of the cheaper brands being brought in were not designed with consideration for a hot and humid climate.

This is even true for some cars in the past. I knew someone whose expensive european car's engine would cut off in the middle of driving because its' on-board safety thermostat would trigger. This continued to happen dispite having the thermostat adjusted. On the other hand, can you drive worry free knowing that the safety thermostat is set higher then the recommended safe operating temperature? (He gave up and sold the car in the end.)

Hmmm... maybe we have to add on to the cost of planted tanks now... by installing water sprinklers and smoke detectors over our tanks as recommended equipment!

[valice]

This is even true for some cars in the past. I knew someone whose expensive european car's engine would cut off in the middle of driving because its' on-board safety thermostat would trigger. This continued to happen dispite having the thermostat adjusted. On the other hand, can you drive worry free knowing that the safety thermostat is set higher then the recommended safe operating temperature? (He gave up and sold the car in the end.)

Sounds like a BMW to me...

I noticed also that most aquarium equipment products do not go through the PSB check which we see for other home appliances. So we really need to be careful... Especially filters which is on 24/7 365.25 days a year!

Think a few years ago, there was a newspaper article reporting on a house being burnt down as a result of the OHF's external pump overheated and caused a fire when there was no one at home. After that, think these types of pumps are not allowed to be sold... Now they seemed to have made a come-back in some shops.

[aquarius]

I think a safer bet would be to avoid buying equipments that are very cheap or some china made brands cos the quality will be an issue. Not worth the risk especially since water and electricity are bad combinations.

[kadios]

The ballast was placed away from the tank with adequate ventilation. My suspicion is the capacitor simply died away. My dad suggest to open up the ballast periodically to check it. From his experience, a "bloated" capacitor signals a potential failure. I guess there is no other options then. Sigh...

Cheers!

[Fei Miao]

kadios-
sorry to her about this, scary.... glad that your mom's around to put out the fire and prevent more serious damage.