500kVA Trasformer Maintenance 1

[lukin1977]

We have a 500 kVA 23kV/380V transformer at our plant
We don't do any maintenance to it at all

Can anyone guide me about what is the usual maintenance that has to be done to this type of transformer?

 

[oldfieldguy]

Consider that the utility companies have hundreds of these things in service and never touch them, there is a good case to be made for doing nothing.

In my case, I have many pad-mount types in the 15kV-480 range. Basically we open up the connection compartments annually to inspect for visible problems, and that's it. On a three-year basis we gon into the connection compartments, do a thermographic scan for poor connections under load, then ed-energize the transformer and wipe everything down clean.

If you need to get a bit more active, draw oil samples for analysis annually.

old field guy

 

[ScottyUK]

Your maintenance regime should be based on how critical that transformer is to the owner. Where I'm located the biggest enemy is corrosion because we're a coastal facility in a heavily industrialised area: radiators and instruments are usually the first casualties.

 

[lukin1977]

 

[oldfieldguy]

lukin-

Your transformer looks well cared for.

Keep it that way and it should last a long time.

Track the moisture content in your insulating fluid. If it starts to climb, remediation (dehydration) is a good idea.

old field guy

 

[DTR2011]

Oil samples (Quality and DGA) are not very expensive and there are many service companies that can perform this work. For maybe (US) $300-500 you can have the samples taken and analysed. Very inexpensive insurance and many facilities insurance providers require this. It looks like there is a sample valve below the LV connections. Depending on local safety rules and utilization of proper safety equipment, the sample could be taken on line.

 

[prc]

I could not find a silica gel breather from the photograph. Normally there will be a drying gel breather connected to the air space of conservator. Most important part of maintenance is keeping the gel always in dry condition. Don't wait it to be saturated with moisture. Moisture is the silent killer of such transformers. Never allow an oil leak to persist. Moisture can get in through such leaks also.
Infrared temperature check of bushing connections - check once in an year. Oil test including DGA may be done once in 3-5 years.

 

[lukin1977]

The breather does not have silica gel. I think I could install a silica gel breather easily in the oil expansion tank
I will do oil analysis every 3 years and terminals temperature check every 3 months (we have the equipment to do it)

thanks to all