Ozone smell in Transformer room

[Mbarkawi]

Dear Community,

Since 5 to 6 months we started smelling the odor of O3 (Ozone) in our Transformers room.

We have 11 Dry Transformers 13800V to 400V installed in 1 closed room (cooled down with HVAC system).

Transformer type: Trihal Cast Resin 1MVA, 2.25 MVA and 3.5 MVA

Did any one of you experienced this issue.

Thanks in advance

[HelvinHermanT · Accepted solution]

Hi,

The Ozone Smell is most likely due to presence of Corona (Partial Discharge).

When entering to substation room, experts may try to detect the presence of Corona (Partial Discharge) by sensing the ozone smell.

The corona may happen in Dew Point temperature where condensation will cause corona. See dew point table chart.

One of my experience with customer report that there is a "crackling sound" inside on of his MV Cubicle. The room is regulate with air conditioner, so the humidity will be low that difficult to cause water condensation. But finaly we found out that one of the air flow from the air conditoner is directly flows to one side of the MV Cubicle's side panel that will cause big temperature difference between the outer surface and the inside cubicle of the panel. This big difference in temperature cause Dew Point temperature (Water Condensation inside cubicle).

Please try to check also for a crackling sound to detect corona.

Hope help.

[Mbarkawi]

Hi HlvinHerman,

Thanks for your feedback.

We checked our MV Switchgears and found High level of partial discharges in some units.

We will work it with Schneider local team (in Jeddah KSA)