ZSM-METER-DTSU
ZCS Azzurro ZSM-METER-DTSU three-phase energy meter for reading consumption and grid exchange on ZCS Azzurro three-phase and hybrid inverters. RS485 Modbus-RTU communication and bidirectional measurement.
Mounts on a 70 mm DIN rail (4 modules). Supplied with 3 current sensors with 5 A secondary and a scale factor programmable from the display, so they do not need to be purchased separately.
The ZCS Azzurro ZSM-METER-DTSU is the three-phase energy meter that lets ZCS Azzurro inverters know in real time how much the home or business is consuming and how much power is being exchanged with the grid. It underpins self-consumption optimisation, battery charge and discharge management, and the export limitation function.
What the meter does in a storage system
Without a meter, the inverter only knows how much the solar array is producing, not how much the building is drawing. The ZSM-METER-DTSU is installed downstream of the utility meter and measures energy flow across all three phases in both directions. With that data, the hybrid inverter decides moment by moment whether to send production to the loads, to the battery or to the grid, and at night how much to draw from storage.
Bidirectional measurement distinguishes imported from exported energy, which is what makes zero-export operation configurable when the system must not feed the grid.
Three-phase or single-phase: which meter you need
This is the most common ordering mistake on this item. The ZSM-METER-DTSU is the three-phase version, intended for three-phase inverters and three-phase HYD hybrids, with an integrated 380 V supply. For a single-phase system you need the ZSM-METER-DDSU instead, which is a different part number, takes less room in the board and works by direct connection.
There is a second important difference: the DDSU measures current directly at its terminals, while the DTSU works through current transformers. The 3 CTs required are already included, so they do not need to be ordered separately.
ZSM-METER-DTSU technical specifications
| Type | Three-phase energy meter |
| Mounting | 70 mm DIN rail (4 modules) |
| Dimensions | 100 x 72 x 65.5 mm |
| Communication | RS485 (Modbus-RTU) to inverter or Connext |
| Current measurement | Via sensors with 5 A secondary, scale factor programmable from display |
| Current sensors | 3 included |
| Bidirectional measurement | Yes |
| Accuracy | 0.1 A |
| Power supply | Integrated, 380 V three-phase |
| Rated working voltage | 220 V phase-neutral |
| Frequency | 50/60 Hz |
| Consumption | 1.25 W |
| Operating temperature | -25 °C / +60 °C |
| Weight | 0.8 kg |
Installation and configuration
- Board mounting on DIN rail, 4 module footprint
- The 3 CTs go on the three phases downstream of the utility meter, respecting the direction marked on each sensor
- RS485 connection to the inverter using shielded twisted pair, observing A and B polarity
- Set the CT scale factor from the display to match the ratio of the sensors installed
- Final check of power signs: a CT fitted the wrong way round swaps import and export
Frequently asked questions
Are the current sensors included or bought separately?
They are included. The ZSM-METER-DTSU is supplied with the 3 current transformers with 5 A secondary needed to measure across the three phases. This differs from the single-phase DDSU model, which works by direct connection without CTs.
Can I use it on a single-phase system?
No. The DTSU is designed for three-phase networks with an integrated 380 V supply and is intended for three-phase inverters and three-phase HYD hybrids. For a single-phase system the correct part number is ZSM-METER-DDSU.
How much room does it take in the distribution board?
The meter mounts on DIN rail and occupies 70 mm, equal to 4 standard modules. Overall dimensions are 100 x 72 x 65.5 mm, and you should also allow room for the three incoming CT leads and the RS485 twisted pair.
Is it needed even without a storage battery?
It is useful in two cases even without storage: to monitor real consumption and energy flows from the ZCS portal and app, and to enable export limitation where the system must not feed energy to the grid. With storage it becomes an essential component.
Why does the meter show values with reversed signs?
In almost every case one or more CTs are fitted the wrong way round relative to current direction, or the scale factor does not match the sensors installed. Both can be checked from the meter display without dismantling anything.