# Ozone in a transformer room?



## ponyboy (Nov 18, 2012)

I'd be looking at the battery chargers. Every time I've installed battery chargers in a confined space I've put in hydrogen monitors tied to a supplemental exhaust system.


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## Wirenuting (Sep 12, 2010)

If it's not the batteries giving off the smell, it may be an impending fault on the transformer feeds.

We had a vault in the hospital that for a few weeks smelled of "something".
It had bus work and breakers and switchgear on the 4160 primary side. 
Everything checked out ok just days before a feed blew. 
Even the generator room next to it was checked. Every time I ran the generator the smell got stronger for only a few minutes. We had a large exhaust fan in the gen room that ran when the gen did. 

Turn out it was an old underground feeder that ran up from out steam/power house. The switch that it feed had been open and unused for 20+ years. The fault was about 10' down the pipe. We cut and abandoned it. 

We normally were fed from 2 separate PoCo substations and this feed from our power house was a "just in case" install in 1960.


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## chrisfnl (Sep 13, 2010)

I should clarify, only the chargers are there, the batteries are in a separate location, also no connected ducting.

The transformers are all fed 600v, that's the highest voltage in the space, ignoring the 4160 which is not usually live (it's a step up xfmr from 600 to 4160)


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## Moonshot180 (Apr 1, 2012)

so are you sure you were able to IR-inspect everything? What you are smelling tells me something is overheating. We lost a resistor in a DC-DC converter earlier this year, and that is exactly what it smelled like.

Since you have chargers in there..maybe take a closer look (if you can power them down, and remove all potential from them) to make sure yall are not overlooking something?


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## cuba_pete (Dec 8, 2011)

*Corona*



chrisfnl said:


> Has anyone experienced ozone in a low voltage transformer room?
> 
> Anyone have any idea about potential sources? Is this normal with LV gear?


Not normal for low voltage gear...to be sure...but the DC chargers may be suspect. Even then, the amount corona needed to make ozone should be on the order of thousands of volts DC.

Corona discharge can be difficult to detect even in a completely dark environment and may not show up in IR. Look for the effects of corona near connections. Time lapse photography may aid in locating the source.


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## Zog (Apr 15, 2009)

cuba_pete said:


> Not normal for low voltage gear...to be sure...but the DC chargers may be suspect. Even then, the amount corona needed to make ozone should be on the order of thousands of volts DC.
> 
> Corona discharge can be difficult to detect even in a completely dark environment and may not show up in IR. Look for the effects of corona near connections. Time lapse photography may aid in locating the source.


Agreed, shouldn't be corona on LV systems and by the time an IR camera picks that up it is near failure. A corona camera is the best way to pick that up or via Ultrasound (Should pick it up as soon as you walk in the room)


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