15 Advantages Of Cast Resin Dry-Type Transformers
When researching the advantages of cast resin dry-type transformers, you may find the information available to be somewhat lacking. Generally, only a few of the cast resin transformer’s features are well-known. Most noteworthy of these – its minimal fire risk as a result of zero oil usage.
But that is only one of many benefits cast resin transformers can offer when compared to oil-type transformers. This post aims to explore all the advantages of using dry-type transformers:
*This post is based on the German-engineered SGB cast resin dry-type transformer. Originally published in March 2016.
1. LOW FIRE HAZARD.
The transformer insulation consists of an epoxy resin and quartz powder mixture, that allows the winding to be flame-retardant, self-extinguishing, and almost maintenance-free. Thus, eliminating the need for costly fire extinguishing equipment. It also won’t produce toxic gases, not even under the effects of arcing.
2. ZERO OIL USAGE.
The cast resin transformer only needs air to cool. Thus, eliminating extra cost and labor on:
+ Liquid-level checking.
+ Oil testing and oil recycling costs.
+ Dielectric testing for moisture absorption.
Cast resin transformers pose no oil leak or pollution risk to the environment.
In contrast to oil-cooled transformers, a cast resin transformer exploding during normal operation is highly unlikely.
5. LOW COST INSTALLATION.
There are almost no restrictions on the installation site. Furthermore, there will be no groundwater protection costs during site preparation. Cast resin transformers can also have a location closer to the load. The closer the transformer is to the load, the lower the losses and cabling cost.
Cast resin transformers have a MTBF of 2,100 years, a service life of 20+ years, and a low failure rate. This translates into a highly reliable component of any electrical infrastructure.
What is meant by MTBF?
MTBF “Mean Time Between Failures” refers to the expected amount of time that elapses between one system failure and the next. That is, from the up-time after one repair, until the next failure.
What is meant by service life?
Service life is the expected lifetime of a product, OR the acceptable period of its use in service. It’s the time that any manufactured item can be expected to be ‘serviceable’ or supported by its manufacturer.
7. LOW MAINTENANCE.
Cast resin transformers only need air to cool, and liquid testing becomes obsolete. Its smooth coil surface eliminates heavy dirt build-up, even in the most extreme circumstances. The only recommended maintenance is a routine visual inspection by technical personnel, and a wipe down of the transformer as required.
8. HIGH SHORT-TIME OVERLOAD CAPACITY.
Oil-type transformers are manufactured with a multi-layer winding of the coil. This method is the best and most reliable option from an electrical point of view. So when applying this principle in cast resin transformers, manufacturers are able to ensure:
+ Safe handling of high surge voltages.
+ Balanced surge voltage stress across the winding.
Multi-layer winding also permits the easy introduction of extra cooling ducts in the coil. By gaining a larger cooling surface area, a uniform temperature distribution occurs.
The transformer windings may crack due to expansion when heat arises in the transformer. This is a common issue with dry-type transformers. But the glass fiber reinforced cast resin system, prevents the winding from cracking.
The complete embedding of the transformer winding in resin, prevents the penetration of moisture. This results in low maintenance and an extended transformer life.
11. LOW NOISE LEVELS.
The coil support system has unique developed spacers, which isolate vibrations from the iron core. As a result, noise levels during operation are reduced by a considerable amount.
12. COMPACT DESIGN.
Cast resin transformers use a smaller surface area and have a lower height.
13. VIBRATION PROOF.
For high vibration applications, a 3G rated solution is available upon special request by the client, and can be further up-rated for extreme conditions.
14. OPERATION IN EXTREME CONDITIONS.
Transformer operation is possible in ambient temperatures between -50°C and 50°C.
Using cast resin transformers saves resources and reduces CO2 emissions. Its design and operation is considerate of the environment through:
+ A long service life of 20+ years.
+ Its low own consumption; meaning it uses less electricity.
+ 90% recyclable transformer materials = less waste.
Some manufacturers will even reclaim used equipment at the end of its life-cycle, free of charge.
The choice between a cast resin and oil-cooled transformer is always application dependent. Before making a decision, be sure to consider all requirements of the environment and conditions it will operate in.