Why do you need an MID-certified CEM sub-meter?

Circutor | 21 de April de 2022

In the following article, we would like to explain why it is important to use MID-certified CEM sub-meters. We also discuss the different applications in which these devices are useful. Circutor is very much aware of the need to care for the environment, which is why we understand the increasing need to determine the different consumptions of an installation in order to more accurately identify what locations are consuming the expected amount, and which have excessive consumption at certain times of the day.

This is where the need to use the sub-meters comes in. As their very name indicates, these meters measure the consumption on each of the different lines or loads of your installation, since they are designed to be installed in different sub-panels.

There are many different types of installations where an energy meter is needed. To address this need, we offer our CEM family of meters, which includes solutions for direct and indirect measurement, as well as for single-phase and three-phase installations.

Contadores CEM


Single-phase, direct measurement meter. Direct measurement up to 50 A (1 module)


Single-phase, direct measurement meter. Direct measurement up to 100 A - RS-485 (1 module)

CEM-C21-T1 / CEM-C21-DS / CEM-C21-485-T1 / CEM -C21-485-DS

Three-phase, direct measurement meter. Direct measurement up to 65 A - RS-485 (4 module)

CEM-C31-T1 / CEM-C31-DS / CEM-C31-485-T1 / CEM -C31-485-DS

Three-phase indirect measurement meter .../5 A with RS-485 (4 module)

CEM meters also feature RS-485 communications. This way, once installed, all the consumption can be monitored remotely using PowerStudio (energy management software). This makes the overall control of your installation much easier.

One of the most important features of CEM meters, one that is worth emphasizing, is their MID certification (EN 50470).

What is the MID certification and when is it required?

The MID certification is based on the European EN 50470 regulation on metering equipment, which requires meters to comply with a series of characteristics, including class B accuracy for measuring energy consumption. In other words, it ensures that meters with this MID certification will correctly measure an installation's actual consumption. To give you some idea, class B allows a maximum error of 1% when measuring active energy.

certificado MID

This certification is required in Europe for those meters that are used to re-invoice energy use, since, as noted, they guarantee end users the reliability of their consumption readings.

Therefore, whenever a sub-meter is going to be installed for the purpose of billing the end user an amount for the energy consumed, it must be MID certified.

Here is a straightforward example: imagine a campsite where users consume different amounts of energy, depending on their needs. Often times, every campsite user is charged a fixed fee, meaning they all pay the same, regardless of the final consumption of each. However, if a CEM meter is used, each customer can be billed for the exact amount of energy used. The result is fairer billing for everyone. We must also remember that since the billing of energy is involved, the meters have to be MID certified in this case.

This same example can be applied to hotels, housing complexes, water ports, shopping centres and many other facilities that have individualized consumption, and that often issue bills with fixed amounts regardless of the real consumption of the individual customers.

As you can see, it is becoming increasingly important to be able to track the consumption of every part of an installation. Now more than ever, consumers have to be charged based on their actual energy use as measured by sub-meters, not using a flat rate that is unfair to end users.

In short, we recommend that whenever you install a sub-meter in order to re-invoice the energy consumed, that it be MID certified.


Shopping centres

Flats and residences


Ports and Campgrounds