On-site maintenance

Choking coils / Measurement of harmonic pollution

Prevention is better than cure. Not surprisingly, insurance companies often use this proverb, since any damage that can be prevented does not have to be paid out afterwards.

Therefore, insurers consider prevention of paramount importance, and they do not hesitate to recommend or even prescribe expensive preventive measures to policy holders in order to prevent damage. Especially if the purpose is to prevent extensive damage due to fire, expensive equipment, such as extinguishing systems, is made obligatory to qualify for insurance.

It often seems as if insurance companies prescribe preventive measure without thinking about the cost involved in these obligatory investments. Even so, some insurers do care about your wallet and actively assist in looking for low-cost preventive measures to avoid fire damage.

Preventive measure do not necessarily have to cost a lot of money. At the request of a large insurance company, EMRI has developed a special choking coil as a preventive measure against fire in electrical systems. The purpose of the coil is to filter harmonic currents in electric systems. A detailed description of EMRI’s choking coil and its operation

Measurements and installation of the choking coils of EMRI at several plant nurseries in the Netherlands have proved that this is an effective solution for filtering of harmonic currents, allowing you to save a lot of money compared with the installation of very costly filter systems.

If you consider installing one or more choking coils of EMRI in your installation, we recommend that you go through the following steps:

Step 1 - Measurement, analysis and advice

EMRI can measure the pollution in your installation using special grid analysis equipment. On the basis of this analysis it is possible to determine not only the magnitude of the harmonic current but also the type of EMRI choking coil(s) required for your installation. Furthermore, fitting a test model of an EMRI choking coil will allow immediate measurement of the effect of the harmonic current reduction by the EMRI choking coil. We can assure you that you will be stunned by the result!On the basis of these measurements we will give you advice on the installation of one or more EMRI choking coils, depending on the set-up of your installation. Regardless of whether you have a grid connection in combination with one or more generators, it is always possible to include EMRI choking coils in this. In some cases adjustments to your existing installation may be required, such as separating neutral from earth. Naturally, such adjustments will be included in our advice.

Step 2 - Selection and installation

On the basis of the advice arising from the measurements, you may decide to proceed to final selection and installation of one or more EMRI choking coils. The cost depends on the number of choking coils to be included and their place in the installation. You will receive a report from us containing the results of measurements before and after the installation of the EMRI choking coil. You can use this report to prove - to your insurance company, for instance - the extent to which the harmonic current has decreased.

Step 3 – Protection

Although the grid analysis provides a reliable picture of the pollution in your grid, it may occur that after some time the harmonic currents increase. This may have various causes, such as a change in the size of your installation or ageing of your switching equipment. These are factors that have a negative effect on the harmonic currents, possibly resulting in overloading and overheating of the choking coil and your electrical installation.

To prevent damage, the choking coil can be fitted with a permanent protection against overheating. If the temperature of the choking coil exceeds a certain threshold, the protection circuit kicks in, thus preventing damage to your choking coil or parts of your electrical installation.