Automatic fire detection system on power transformer

[SA07]

Hi
We have 2 power transformers 55 MVA 11/66 kV side by side as shown in the picture. We have a water deluge system with a manual valve already installed.
What automatic fire system is used on such transformer to open the water deluge in case of a fire?

 

[thermionic1]

I have seen the transformer protection lock out relay (86T) trip the deluge system at a large generating station.

 

[sushilksk]

fire detection by quartzoid bulbs is generally used for 132kV and above, same can be considered here.

 

[davidbeach]

I would want the lockout rolled before releasing the water, the detection system can trip the lockout. But I wouldn’t release water just because the lockout rolled. A necessary condition, but not a sufficient condition.

 

[Ifrat Mahmud]

Fire protection is used to extinguish fire. So at first fire has to be detected. It can be detected by Quartzoid bulb as sushilksk has told already. But there may be false detection.
Fire means oil comes out of transformer. In this circumstances differential must be operated. And device mechanical protection will also operate.
So to release fire protection there have to be fire detection, differential operation and device mechanical protection operation.
Thanks.

 

[prc]

Normally provision made for Fire detection sensor + either of differential or Buchholz/Pressure release device. Many cases mechanical protection may not operate and hence all the three are not connected in series.

 

[davidbeach]

I want the lockout tripped before water hits the bushings. The release of water can be what trips the lockout, but I darned well want the transformer deenergized first. Not entirely trusting fire detection systems, I'd personally want either an 87 or an oil device to trip, but if you're more trusting of the fire detection system, just have it trip the lockout as the water is being released. By the time the water reaches the nozzles the transformer will be deenergized.

 

[prc]

Fully agree. When we connect differential and Buchholz in parallel and then connect them together with fire detectors in series , that purpose will be achieved.Differential or/and Buchholz will trip the circuit and then activate the water valves.