SGM-C4 Compact Meter

Product information

The SGM-C4 is a sturdy standard device with the following features:

• Case compliant with DIN standard for three-point mounting with terminal cover suitable for holding a BAB adapter
• Flexible measurement via shunts with intrinsic immunity to harmonics and external magnetic fields: +A or -A with reverse running lock, +A/-A bi-directional, [A] direction -independent, |A| direction-independent

• RS-485 bus interface for remote communication
• PIN-protected data display and output
• Front optical interface for local data provision
• Multi-functional display for meter data and historical data over 2 years
• Sturdy, low-emission power supply
• Output of readings and grid quality parameters
• Optional dual-tariff version with external control via accessory terminals

The daily, weekly, monthly and annual values of active power over a period of two years are recorded in the ring buffer as historical data and displayed under PIN protection. The front optical interface is used for local provision of measurement data and device information according to SML/COSEM at 1-second intervals. This function is also PIN protected. PIN entry is via the front-side button or optionally via the optical button.

The RS-485 interface serves for system communication with a baud rate of 9.6 kbit/s.  The protocols employed are SML/COSEM in the application layer.

Standard functions

In accordance with statutory provisions, the meter acts as a reliable and secure metering device for acquisition of billing-related active power quantities and grid-friendly measurement data and parameters, such as effective values of line voltage and current, power, phase angle and line frequency.

Active power is measured in both directions, with the following measurement modes being available:

• Measurement in one direction with reverse running lock
• Measurement of absolute magnitude |A|: Direction-independent sum of magnitudes in all lines
• Measurement in two directions: +A and -A
• Measurement of power consumption over two phases with delivery over one line

The current sensors used are sturdily mounted, precise shunts suitable for accuracy class B.

Actual power values on all lines are logged internally and available over the data interfaces. The measurement mode can be set in the factory according to metering requirements.

The meter provides the following grid functions:

• Active power P_L1, P_L2, P_L3 calculated as an average over 1 second, resolution 0.1 W
• Effective values of line and line-to-line voltages U_L1, U_L2, U_L3 calculated as average values over 1 second, accuracy 1% of measured value, resolution 0.1 V
• Effective values of line currents I_L1, I_L2, I_L3 calculated as average values over 1 second, resolution 0.1 A, accuracy 1% of measurement
• Phase angles φ_L1, φ_L2, φ_L3, accuracy/resolution 1° relative to the fundamental frequency
• Line frequency f_line, accuracy 1%, resolution 0.1 Hz

Optional Functions

As an option, the dual-tariff function with external control is available via terminals 13 and 15. The tariff registers in both power directions together with the current tariff are shown on the display. Removing the terminal cover is detected as tampering and logged.