Carlo Gavazzi Meters - Because Efficiency Starts Here!

Today we will discuss energy meters used to measure consumption, voltage, current, network frequency, power factor, active power, reactive power, apparent power, etc.

Nowadays, the field of energy consumption analysis is gaining relevance whenever a new project begins. In the hotels where we design all the electrotechnical components from scratch, from the arrival of the medium voltage electrical network, through the step-down transformers, main low voltage switchboard (QGBT), subpanels, floor panels, and other panel it is common to install meters on both the normal power busbar and the safety busbar supported by the Generator set.

These two power groups are further subdivided into two categories: lighting circuits and circuits for outlets and other equipment. With these subdivisions, it is possible to record the consumption derived from normal and emergency lighting circuits, as well as the general normal and emergency power circuits.

With these meters interconnected through Modbus RTU, Modbus TCP/IP, BACnet, M-Bus, or Ethernet/IP communication, it is possible to integrate them into the hotel's centralized technical management system, thereby obtaining real-time instantaneous consumption data and detecting possible anomalies.

Here, we can truly understand the powerful tool we have at hand, and the ability to make decisions regarding efficiency, especially if associated with control circuits via home automation or timers.

Currently, the meters I install and program are from the manufacturer Carlo Gavazzi, and the most frequently used models are the EM111, EM330, and EM340 meters. Below are the differences between the models.

In addition to the meters, the manufacturer Carlo Gavazzi also offers Analyzers, which are more robust devices compared to meters and record additional information such as harmonics.

Configuring the Meters

Configuring these devices is relatively easy and is done directly on the display using capacitive buttons. First, you need to log in and enter the factory password, which is 0000. The factory password can be changed, but I personally do not recommend it to facilitate future interventions by other companies unless the client requires it. After logging in, you can navigate through the following menu items:

Most important parameters to configure on the EM340 model:

• P1 - Password
• P2 - Change Password
• P3 - Type of installation (3-Phase with neutral or 3-Phase without neutral)
• P6 - Measurement (whether it is consumption, production, or simultaneous consumption and production)
• P14 - Address
• P15 - Communication baud rate, I usually set it to 9600
• P16 - Parity | P16-1 - Program Parity | P16-2 - Stop Bit
• P17 - Reset
• P18 - Exit

Parameters to configure on the EM330 model:

The configuration of the EM330 meter is exactly the same as the EM340 model, except for the current transformer settings, which do not exist on the EM340 since it is a direct connection meter. On the EM330, it is necessary to specify the current transformer ratio.

For example, for these current transformers, you would need to set the value of 160 in the CT parameter, as they are 800/5 A.

Parameters to configure on the EM111 model:

This meter is a direct connection and does not have as many functionalities compared to the three-phase meters.

Communication Protocol

The communication between devices must always respect the same settings for all devices (baud rate, stop bit, and parity), changing only the address, which is unique for each meter. Two meters with the same address will cause a conflict, resulting in communication failures.

Conclusion

In total, 15 meters were installed:

• 2 EM111 Meters
• 6 EM330 Meters
• 7 EM340 Meters

For data processing, I used a Carlo Gavazzi UWP monitoring gateway, which will be discussed in another article.

Technical Documentation