Sungrow DTSU666-20
Official manufacturer EU / AU (CT count differs by region) verified Sept. 3, 2026
Unresolved safety-relevant conflict
Two sources give different figures for a value on this product and nobody has resolved it. The specifications below are shown as recorded, but this product must not be treated as verified for engineering purposes until the conflict is closed.
Two sources give different figures for a value on this product and nobody has resolved it. The specifications below are shown as recorded, but this product must not be treated as verified for engineering purposes until the conflict is closed.
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Identity
| category | smart_meters |
| channels | Single-channel or dual-channel CT operation - CT1 terminals 1/3/4/6/7/9, CT2 terminals 31/33/34/36/37/39 |
| device_type | CT-connected three-phase DIN-rail energy meter for Sungrow inverter systems |
| direct_or_ct | CT-connected (333 mV low-voltage-output CTs or Rogowski coils) |
| ean | UNKNOWN |
| manufacturer | Sungrow |
| market_version | UNKNOWN |
| model | DTSU666-20 |
| mpn | UNKNOWN |
| phase_count | Three-phase; configurable 3P4W (setting "n.34") or 3P3W (setting "n.33") |
| product_family | DTSU666 platform, Sungrow '-20' variant |
| product_name | DTSU666-20 |
| product_status | active |
| product_type | Three-Phase Smart Energy Meter |
| region | EU / AU (CT count differs by region) |
| region_variants | EU packages ship 3 CTs; Australian packages ship 2 CTs (per QIG). The EU product page lists the SKU as "DTSU666-20 (+2CTs)". |
| sku | UNKNOWN |
Electrical
| accuracy_class | Class 1 |
| ct_output | 333 mV |
| ct_ratio | voltage-output CT, secondary 0.333 V (guide prints the CT ratio as '***/0.333V' with the primary current left as a placeholder); primary rating not stated in the fetched guide disputed |
| export_limitation_support | True |
| grid_frequency | 50 Hz / 60 Hz |
| input_voltage_range | 50 - 280 Vac L-N / 85 - 485 Vac L-L |
| max_current_a | UNKNOWN |
| measurement_type | CT-operated three-phase meter with voltage-output current transformers (0.333 V / 333 mV secondary); voltage sensed directly at L1/L2/L3/N; bidirectional import/export measurement |
| modbus_rtu |
true - quick installation guide Ver17: 'Modbus-RTU address=001 Baudrate=9600 None parity, 1 stop bits'
Quick Installation Guide - Three-Phase Smart Energy Meter DTSU666-20 — 'Modbus-RTU address=001 Baudrate=9600 None parity, 1 stop bits'
|
| modbus_tcp | UNKNOWN |
| nominal_voltage | CONFLICT - see data_conflicts (datasheet V1: "240 Vac L-N / 415 Vac L-L"; QIG Ver17-202605: "230Vac L-N / 400Vac L-L") |
| phase_type | three-phase |
| power_consumption | CONFLICT - see data_conflicts (datasheet: "<= 1.5 W (6 VA)"; QIG: "1.2W") |
| rated_current_range | 0 - 100 A or 0 - 250 A with 333 mV CT; 0 - 1000 A or 0 - 3000 A with Rogowski coil |
| rs485 | True |
| sources | [{'url': 'https://info-support.sungrowpower.com/application/pdf/2025/07/17/SHRT%20User%20Manual.pdf', 'title': 'SH5.0RT-SH10RT(-20) User Manual', 'doc_type': 'manual', 'publisher': 'Sungrow', 'revision': 'SH5.0-10RT&SH5.0-10RT-20-UEN-Ver24', 'doc_date': '2025-03', 'language': 'en', 'region': 'global', 'accessed': '2026-09-01', 'confidence': 'officially-verified'}] |
| supported_inverter_brands_models | ["Sungrow SH5.0RT-20/SH6.0RT-20/SH8.0RT-20/SH10RT-20 (manual: 'SH5.0-10RT-20 matches DTSU666-20 smart energy meters')"] |
Physical / mechanical
| depth_mm | 65.5 |
| dimensions_w_h_d_mm | 118 x 72 x 65.5 (QIG) / 72 x 118 x 65.5 (datasheet - same three dimensions, different axis order) |
| din_modules | UNKNOWN |
| din_rail_type | UNKNOWN (DIN-rail form factor; rail type not printed) |
| display | LCD display |
| enclosure_material | UNKNOWN |
| height_mm | 72 |
| mounting_type | ['DIN-rail'] |
| torque_specs | UNKNOWN |
| weight_kg | 0.8 |
| width_mm |
118
Quick Installation Guide - Three-Phase Smart Energy Meter DTSU666-20 — technical data, 'Dimensions 118 x 72 x 65.5 mm'
|
Installation
| billing | "cannot be used for billing purposes" (QIG) |
| ct_direction | "The arrow on the CT should always point to the load side." A negative displayed value indicates the CT primary/secondary connection must be reversed. |
| ct_orientation_note |
'The arrow on the CT should always point to the load side.'
Quick Installation Guide - Three-Phase Smart Energy Meter DTSU666-20 — CT installation step
|
| export_limitation_role | UNKNOWN - the fetched documents describe measurement and data collection only; no explicit zero-export/export-limitation function is stated in them |
| indoor_outdoor | indoor - distribution board / consumer unit (IP20) |
| mounting | 35 mm DIN-rail, in the sub-distribution cabinet |
| mounting_orientation | UNKNOWN |
| role | Import and export energy measurement across grid and inverter; per-phase voltage, current, power factor and active power; load-consumption visibility |
| second_channel_use | CT2 is used to meter a third-party PV inverter; per the QIG, CT2 "does not need to be connected if a SUNGROW PV inverter is used" |
| topology | Meter installed between the grid connection point and the inverter(s); an external disconnect switch must be installed between the meter and the grid-connection point |
Environment
| humidity | <= 75 % non-condensing |
| ip_rating |
IP20
DTSU666-20 (+2CTs) accessory product page — accessory product page specification block, 'Protection Class IP20'
|
| max_altitude_m | UNKNOWN |
| operating_temperature_c |
-25 to +70
Quick Installation Guide - Three-Phase Smart Energy Meter DTSU666-20 — '-25 C ... +70 C'
|
| relative_humidity | < 75 % (non-condensing) |
| storage_temperature_c | UNKNOWN |
Interfaces & connectors
| baud_rate | 9600 bps default; selectable 1200 / 2400 / 4800 / 9600 |
| communication | RS485 x 1 |
| modbus_address | 1 by default, programmable in the range 1-254 |
| modbus_rtu | yes - address 001, 9600 baud, no parity, 1 stop bit |
| parity_stop_bits | None parity, 1 stop bit by default; selectable N.1, N.2, E.1, O.1 |
| protocol | Modbus-RTU |
| protocol_notes | meter ports: CT port for the current transformers; L1, L2, L3, N ports for voltage sensing |
| rs485 | yes - RS485 link to the inverter (RS485 cable supplied) |
| wiring | Meter terminals A and B for the RS485 plug; an 8 m RS485 cable is supplied in the inverter packaging |
Protection
| ip_rating | IP20 |
Certifications
| emc | [] |
| grid_codes | [] |
| mid | UNKNOWN |
| other | [] |
| regional | [] |
| safety | [] |
| standards | EN61326-1, EN61010-1 |
Documents
quick-start
Quick Installation Guide - Three-Phase Smart Energy Meter DTSU666-20
rev DTSU666-20-QIEN-Ver17-202605
quick-start
{# Located but never retrieved: listed, but deliberately not linked, and it
backs no stored value. #}
Quick Installation Guide DTSU666-20 (German portal mirror) — located, not retrieved
rev UNKNOWN
Recorded conflicts
electrical.power_consumption Review required
<= 1.5 W (6 VA) — https://info-support.sungrowpower.com/application/pdf/2023/01/31/DS_20230129_DTSU666-20_Datasheet_V1_EN.pdf
1.2 W — https://info-support.sungrowpower.com/product-materials/4618fcef-2d6a-4575-a7f2-edf7c6d360d3.pdf
electrical.nominal_voltage Review required
240 Vac L-N / 415 Vac L-L — https://info-support.sungrowpower.com/application/pdf/2023/01/31/DS_20230129_DTSU666-20_Datasheet_V1_EN.pdf
230 Vac L-N / 400 Vac L-L — https://info-support.sungrowpower.com/product-materials/4618fcef-2d6a-4575-a7f2-edf7c6d360d3.pdf
environment.humidity Review required
<= 75 % (non-condensing) — https://info-support.sungrowpower.com/application/pdf/2023/01/31/DS_20230129_DTSU666-20_Datasheet_V1_EN.pdf
< 75 % (non-condensing) — https://info-support.sungrowpower.com/product-materials/4618fcef-2d6a-4575-a7f2-edf7c6d360d3.pdf
electrical.ct_ratio Review required
voltage-output CT, secondary 0.333 V (guide prints the CT ratio as '***/0.333V' with the primary current left as a placeholder); primary rating not stated in the fetched guide — stored value
Programmable: CT01 100 A/333 mV, CT02 250 A/333 mV, CT03 400 A/333 mV, CT04 500 A/333 mV; Rogowski RS01-RS04 1000 A - 4000 A — incoming package
Detected during import sungrow-full-portfolio-2026-09-03
Additional documented parameters
Recorded verbatim from the source; no schema field exists for these yet.
| CT cable length | 6 m |
| CT output voltage | 333 mV |
| Grid frequency | 50Hz/60Hz |
| Input voltage range | 50 ... 280Vac L-N / 85 ... 485Vac L-L |
| Nominal voltage | 230Vac L-N / 400Vac L-L |
| Wiring scenarios | six documented scenarios covering three-phase / single-phase hybrid inverter combinations with third-party PV inverters |
| documented_relationship:inverter_meter | {"to_manufacturer": "Sungrow", "to_model": "SHxxRS; SHxxRT; SHxxT; SG series; SH series", "relationship_type": "inverter_meter", "match_level": "series", "communication_protocol": "RS485 / Modbus RTU", "required_firmware": "UNKNOWN", "required_settings": "Wiring mode n.34 (3P4W) or n.33 (3P3W); CT ratio code CT01-CT04 / RS01-RS04; Modbus address and baud rate as above", "required_accessories": "\"3x 100 A / 333 mV CT or 3x 250 A / 333 mV CT to be purchased\" (compatibility-list footnote)", "region": "EU", "source": "COMPATIBILITY LIST PUBLIC 2026 | VERSION 4.3", "source_url": "https://info-support.sungrowpower.com/market-material/41ab25da-0bbb-451b-8a51-fd4abd3be0bd.pdf", "source_page": "UNKNOWN", "confidence": "officially-verified", "status": "COMPATIBLE", "notes": "Compatibility list names inverter series only - kept at series level. The QIG itself names no inverter models, only \"thre |
| identity.region_as_researched | GLOBAL |
| manufacturer_legal_entity_as_printed | Sungrow Power Supply Co., Ltd. |