Taking a Breath

Conven­tional dehy­drating breathers require regular main­te­nance. In order to elim­i­nate this extra work, energy supplier VSE Verteil­netz GmbH uses the main­te­nance-free solu­tion from MESSKO in all of its trans­formers — saving both time and money.

Atrans­former breathes out and in again a couple of times a year, depending on utiliza­tion. This is because an increase in load causes the insulat­ing medium in the trans­former to heat up and expand, pushing the air in the expan­sion tank out into the atmos­phere. When the oil cools down again, it contracts and draws in the outside air.

Dehy­drating breathers are used to make sure that no mois­ture gets into the insu­lating medium when the trans­former breathes in. Each trans­former mostly has a minimum of two breathers: one for the oil circuit in the tap changer, the bigger ones for the trans­former tank. The substance that elim­i­nates the mois­ture is called silica gel. Thanks to its water-absorb­ing prop­er­ties, it is also used as a desic­cant in other applications—inside the pack­aging of mois­ture-sensi­tive elec­tronics, for example.

As its ability to absorb water is limited, the silica gel in conven­tional dehy­drating breathers has to be replaced and disposed of reg­ularly—around two to three times a year on average. This frequency increases further as more renew­able power is fed into the grid, as this means the trans­former has to work under high load condi­tions more often. For grid oper­a­tors, this is a task that takes up valu­able time and ties up resources, and the resulting costs are not to be under­es­ti­mated.

The main­te­nance-free dehy­drating breathers make life much easier for Karl-Heinz Jenal, oper­a­tional super­visor at VSE Verteil­netz GmbH. (© Alexander Neu)

Karl-Heinz Jenal, who works as an oper­a­tional super­visor at Saar­land-based energy supplier VSE Verteil­netz GmbH and is respon­sible for main­taining the equip­ment, explains: “We have 56 high-voltage instal­la­tions in our grid, each of which contains two trans­formers. Someone has to go out to each one on a regular basis to check whether the desic­cant is still working prop­erly. Over the course of a year, the time spent on main­te­nance really adds up. And then you have to factor in the metric ton of silica gel that we have to dispose of and replace.” At least, that’s how things used to be.

For VSE Verteil­netz GmbH, these tasks and the asso­ci­ated costs will soon be a thing of the past, as all of its trans­formers have been fitted with the main­te­nance-free MTRAB® dehy­drating breather from Rein­hausen subsidiary MESSKO. The breather still uses silica gel, but unlike the previous tech­nology, the MTRAB® is able to regen­erate itself. Sensors measure the mois­ture in the desic­cant. An algo­rithm stored in the control system eval­u­ates these measure­ments and an elec­tric heating system is acti­vated auto­mat­i­cally when the satu­ra­tion point is reached. After around two and a half hours, the silica gel is dry again.

A Cost-Effec­tive Solu­tion

VSE Verteil­netz GmbH first used the MTRAB® in 2008, when it was adding a new trans­former to the fleet. Jens Leinen­bach, head of grid oper­a­tions, recalls: “We were trying to work out how we could cut down on main­te­nance in the long term. That’s why we were keen to try out a new product and see whether it proved its worth in prac­tice.” And the MTRAB® defi­nitely passed the test. Eight years later, VSE Verteil­netz GmbH ordered MESSKO dehy­drating breathers for another 35 trans­formers and in 2019, the company decided to convert the entire fleet.

Karl-Heinz Jenal (right) together with Werner Sammet, Area Sales Manager Europe of Messko/MR, in a substa­tion of VSE Verteil­netz GmbH. (© Alexander Neu)

“We wanted to bring all of our equip­ment up to the same level. We delib­er­ately opted for a quality product—something that is not offered by many manu­fac­turers on the market. The fact that we have been work­ing with MESSKO and Rein­hausen for many years also played a key role in the deci­sion. Having a partner that we know and trust is impor­tant to us,” explains Leinen­bach.

As an addi­tional advan­tage, the MTRAB® dehy­drating breathers can be networked so that error messages are sent straight to the control room. And even if the elec­tronics system fails at some point, the MTRAB® still func­tions as a conven­tional dehy­drating breather. The company has yet to see a single error message: “Our expe­ri­ence has been entirely posi­tive so far. We haven’t had to worry about a thing since the equip­ment was installed,” says Leinen­bach

Simple Instal­la­tion

Jenal, who oversaw the conver­sion work, agrees. “The instal­la­tion process is self-explana­tory and very straight­forward. Our own staff were able to carry out the work when they were going to a primary substa­tion anyway for other reasons.” The new equip­ment has freed up resources that the oper­a­tional super­visor and his team can now allo­cate else­where. When you work for an energy supplier, there are always plenty of other things to be getting on with.

“From a medium and long term perspec­tive, VSE has made the right deci­sion to save costs and, in doing so, joins the ranks of over 1,000 satis­fied customers world­wide who have been success­fully using our MTRAB® dehy­drating breathers for many years,” explains Werner Sammet, Messko/MR Area Sales Manager for Europe.


The MESSKO® MTRAB® has proven itself many times over in the field since it was first launched over 15 years ago — there are now about 80,000 of these breathers installed world­wide. The main­te­nance-free dehy­drating breather mini­mizes the ingress of mois­ture into the insu­lating fluid of trans­formers, tap changers, and other elec­trical equip­ment filled with insu­lating fluids. The MESSKO® MTRAB® can regen­erate the silica gel itself thanks to the use of temper­a­ture and mois­ture sensors combined with intel­li­gent algo­rithms — saving inspec­tion and main­te­nance costs.


Would you like to know more about the MESSKO® MTRAB®?
Werner Sammet, Area Sales Manager Europe is here to help: