In this post, we are going to discuss about both dry transformers as well as liquid type of transformers both of which are used in industrial and utility applications.
Let us first start with dry type of transformer –
These transformers are traditionally used for any application where low and medium-voltage is used in buildings. Due to improved safety this type of transformers are preferred for indoor distribution of power.
Air-cooled transformers can be larger than all liquid-filled products having same capacity and also voltage ratings, therefore they are not the best option for mobile substation or site where space will be limited.
Their ratings can be as high as 3 MVA. For higher capacities, these dry transformers should use air blasting systems for cooling the windings and the core. Due to these restrictions, experts recommend to use 2.5 MVA as changeover point for both dry and also wet products.
Pros of dry-type transformers
- Dry-type transformers are quite practical for any low or medium-voltage sites.
- All environmental risks due to spills and leaks can be eliminated
- In extreme conditions cast coils can outperform conventional transformers.
- Few cast-coil products can offer extraordinary resistance for surges and also short circuits.
- For indoor sites usually dry-type transformers are preferred where safety is top priority.
Cons of dry-type transformers
- Usually dry-type transformers can be more expensive to buy and to operate.
- Difficult to repairs and life recycling is very limited.
- If coils are not cleaned properly then it may pose fire risks.
- For annual maintenance usually needs deactivation and downtime.
- Various electrical losses are significantly higher.
- Cooling system is needed to compensate for heat generated due to losses
- These transformers have usually high operating noises, hence not suitable for every indoor application.
Now let us consider about liquid-filled transformers
Pros of liquid-filled transformers
- Dielectric fluids used in transformers have very high flash points with minimal adverse impact on environment.
- All high-voltage transformers can be recycled.
- Wet-type power transformer can be smaller and much more efficient comparatively.
- Due to lower operating noise these transformers are right for indoor use
- Usually last much longer than dry-type transformers.
- Many recycling options.
Cons of liquid-filled transformers
- All wet-type transformers have not the same safety advantages.
- For reliability fluid testing and also on-site maintenance is needed.
- Additional protocols may be needed for managing risks against fire and environment.
- These transformers may have little lower cooling ratings comparatively.
- Insulating fluids used must be correct for the application.
All these pros and cons of both options will depend on their application and also the client’s budget and also safety requirements.