Huawei DTSU666-HW Smart Power Sensor Quick Guide

1 Overview

1.1 Dimensions

DTSU666-HW

Dimensions: 72 mm (width) x 101 mm (height) x 45 mm (depth). The dimensional tolerance is ± 1 mm.

Installation position: 35 mm.

1.2 Appearance

Specifications on the front panel:

Model: DTSU666-HW Smart Power Sensor
Certifications: CE, UK CA
Power specifications: 230/400V, 3~, 50/60Hz, 400imp/kWh
Channel 1: 5(80)A, Class 1
Channel 2: 1.5(6)A, Class 0.5S, 6400imp/kWh
Buttons: SET, ESC

Nameplate details:

Terminal connections for L1, L2, L3, N
Channel 1 (80A) LOAD
Channel 2 (>80A) LOAD
Type: DTSU666-HW
RS485 communication port
Wiring mode note: The three-phase three-wire is not connected to Neutral (N), and the wiring mode must be set in Smart Power Sensor.
Power consumption: Voltage: 1.5W, 6VA

1.3 Key Specifications

Category	DTSU666-HW
Nominal voltage	230 V AC/400 V AC, 50 Hz/60 Hz
Current measurement range	Direct connection: 0-80 A; Connection through current transformers: > 80 A
Voltage measurement range	90-1000 V (line voltage; potential transformers required if voltage > 500 V)
Electricity metering accuracy	Class 1 (error within ±1%)
Power grid system	Three-phase four-wire or three-phase three-wire
Baud rate	4800/9600/19200/115200 bps (default: 9600 bps)
Operating temperature	-25°C to +60°C
Installation mode	Guide rail-mounted
Certification	CE, RCM, and UKCA

1.4 Port Definition

Input voltage: Connect directly if line voltage ≤ 500 V. Use potential transformers if line voltage > 500 V.

Input current: Connect directly for Channel 1 (0 A to 80 A). Use current transformers for Channel 2 (≥ 80 A).

Cable Inlet:

Channel 2 CT Current Input: Terminals 31, 33, 34, 36, 37, 39 (IA*, IA, IB*, IB, IC*, IC)
Voltage Input: Terminals UA, UB, UC, UN

Cable Outlet:

RS485 Communication: Terminals 25, 24 (RS485A, RS485B)
Voltage Output: Terminals UA, UB, UC, UN

2 Installing the DTSU666-HW

Install the Smart Power Sensor on the standard guide rail of DIN35mm.
Press the Smart Power Sensor downwards onto the guide rail, and then push it in place along the guide rail.

3 Installing Cables

3.1 Preparing Cables

Cable	Port	Type	Conductor Cross-sectional Area Range	Outer Diameter	Source
Channel 1 voltage cable	UA-1, UB-4, UC-7, UN-10, UA-1, UB-4, UC-7, UN-10	Single-core outdoor copper cable	25 mm²	10 mm	Prepared by the customer
Channel 2 voltage cable	UA-1, UB-4, UC-7, UN-10	Single-core outdoor copper cable	4-25 mm²	5-10 mm	Prepared by the customer
Channel 2 current transformer cable	IA-31, IA-33, IB-34, IB-36, IC*-37, IC-39	Single-core outdoor copper cable	2-4 mm²	3-5 mm	Prepared by the customer or supplied with current transformers
Communications cable	RS485A-24, RS485B-25	Two-core outdoor shielded twisted pair copper cable	0.25-1.5 mm²	4-11 mm	Supplied by the manufacturer

NOTE: Terminal screw torque recommendations: 1.7 N·m maximum (0.9–1.1 N·m recommended) for terminals 1, 3, 4, 6, 7, 9, 10, 12; 0.4 N·m maximum (0.15–0.25 N·m recommended) for terminals 31, 33, 34, 36, 37, 39, 24, 25.

3.2 Wiring Scenarios

Current	≤ 80 A	> 80 A	≥ 0 A
Line voltage	≤ 500 V	≤ 500 V	> 500 V
Connection mode	Current and voltage direct connection	Connection through current transformers and voltage direct connection	Connection through current transformers and potential transformers
Connection setting	Direct connection: SPEC = 1 (default)	Connection through transformers: SPEC = 0
Current transformation ratio	CT = 1 (default)	CT = Ratio of the installed current transformer
Potential transformation ratio	N/A	PT = 1.0 (default)	PT = Ratio of the installed potential transformer
Wiring mode	3P4W: net = n.34 (default) 3P3W: net = n.33	3P4W: net = n.34 (default) 3P3W: net = n.33	3P4W: net = n.34 (default) 3P3W: net = n.33

NOTE: Set parameters after cable connections are complete. Refer to section 4 for details.

3.3 Current and Voltage Direct Connection (Current ≤ 80 A and Line Voltage ≤ 500 V)

SmartLogger networking:

Three-phase four-wire connection: Power meter connected to SmartLogger, which is connected to the inverter.
Three-phase three-wire connection: Power meter connected to the inverter.

(1) Shield layer of the signal cable is required.

3.4 Connection Through Current Transformer and Voltage Direct Connection (Current > 80 A, Line Voltage ≤ 500 V)

Current transformers specifications: Accuracy class 0.5, secondary side current 1 A or 5 A.

SmartLogger networking:

Three-phase four-wire connection: Power meter connected to SmartLogger, which is connected to the inverter.
Three-phase three-wire connection: Power meter connected to the inverter.

CAUTION: Ensure the ground cable is installed securely to prevent electric shocks.

NOTE: Set parameters after cable connections are complete. For the three-phase three-wire connection, phase B does not need to connect to a current transformer.

(1) Shield layer of the signal cable is required.

3.5 Connection Through Current Transformer and Potential Transformer (Current ≥ 0 A, Line Voltage > 500 V)

Three-phase four-wire connection:

Cable outlet (OUT): S1 IA, S2 IA', S1 IB, S2 IB', S1 IC, S2 IC'
Cable inlet (IN): UA, UB, UC, UN
Current transformers connected to P1, P2 terminals.
Potential transformers connected to PT terminals.

Three-phase three-wire connection:

Cable outlet (OUT): S1 IA, S2 IA', S1 IB, S2 IB', S1 IC, S2 IC'
Cable inlet (IN): UA, UB, UC
Current transformers connected to P1, P2 terminals.
Potential transformers connected to PT terminals.

CAUTION: Ensure the ground cable is installed securely to prevent electric shocks.

NOTE: Set parameters after cable connections are complete. Refer to section 4 for details.

4 Display and Parameter Settings

4.1 Display

The '←' button switches displays. Set parameter 'disp' for rotation display function.

No.	Display	Description	No.	Display	Description
1	10000.00 kWh	Positive active energy	2	2345.67 kWh	Negative active energy
3	n-9.600	None parity, 8 data bits, 1 stop bit; baud rate = 9600 bps (default)	4	----011	011 represents address (default)
5	UA 220.0 V	Phase A voltage = 220.0 V	6	Ub 220.1 V	Phase B voltage = 220.1 V
7	UC 220.2 V	Phase C voltage = 220.2 V	8	IA 5.000 A	Phase A current = 5.000 A
9	Ib 5.001 A	Phase B current = 5.001 A	10	IC 5.002 A	Phase C current = 5.002 A
11	Pt 3.291 kW	Total phase active power = 3.291 kW	12	PA 1.090 kW	Phase A active power = 1.090 kW
13	Pb 1.101 kW	Phase B active power = 1.101 kW	14	PC 1.100 kW	Phase C active power = 1.100 kW
15	PFt 0.500	Total phase power factor PFt = 0.500	16	FA 1.000	Phase A power factor PFa = 1.000
17	Fb 0.500	Phase B power factor Pfb = 0.500	18	FC -0.500	Phase C power factor Pfc = -0.500

4.2 Parameter Settings

No.	Parameter	Value Range	Description
1	CT	1-6553	Current transformer ratio
2	PT	0.1-999.9	Potential transformer ratio
3	Prot	1: 645 2: n.2 3: n.1 4: E.1 5: 0.1	Communication protocol switchover: 1: Factory mode 2: None parity, 2 stop bits, n.2 3: None parity, 1 stop bit, n.1 4: Even parity, 1 stop bit, E.1 5: Odd parity, 1 stop bit, 0.1
4	Addr	1-247	Modbus communication address
5	bAud	0: 1.200 1: 2.400 2: 4.800 3: 9.600 4: 19.20 5: 115.2	Communication baud rate: 0: 1200 bps 1: 2400 bps 2: 4800 bps 3: 9600 bps 4: 19200 bps 5: 115200 bps
6	nEt	0: n.34 1: n.33	Wiring mode: 0: n.34, three-phase four-wire 1: n.33, three-phase three-wire
7	di SP	0-30	Rotation display time (s): 0: Fixed display 1-30: Time interval of rotation display
8	bLCd	0-30	Backlight illumination time control (minutes): 0: Steady on 1–30: Time of backlight illumination without key operation
9	SPEC	0: ct 1: dc	Channel switchover: 0: Transformer connection 1: Direct connection

4.3 Parameter Setting Operations

Button description: SET means "confirm" or "cursor move"; ESC means "exit"; '←' means "add". Default user password is 701.

Set wiring mode and channel switchover:

Power on → Press SET (once) → Measure display → code 600 → SET → 601 → SET → 6 → SET → Add → Current transformer (SET) or Direct connection (Add) → SPEC → SET → Channel switching (SET) → Wiring mode (Add) → n.34 (Three phase four wire) or n.33 (Three phase three wire) → SET → Password correct, enter into the setting interface.

Set current transformation ratio or potential transformation ratio:

Power on → Press SET (once) → Measure display → code 600 → SET → 6 → SET → 0 → SET → Add → Current transformer (SET) or Potential transformer (Add) → CT (SET) or PT (Add) → Enter ratio value → SET → Password correct, enter into the setting interface.

Set communication address or baud rate:

Power on → Press SET (once) → Measure display → code 600 → SET → 6 → SET → 0 → SET → Add → Communication address (SET) or Baud rate (Add) → Addr (SET) or bAud (Add) → Enter address/baud rate → SET → Password correct, enter into the setting interface.

NOTE: Communication parameters are set before delivery. Check and set parameters if communication is abnormal.

5 Troubleshooting

Symptom	Cause Analysis	Troubleshooting Method
No display after power-on	1. Cable connection is incorrect. 2. Voltage supplied to the meter is abnormal.	1. Connect cables correctly (see wiring diagrams). 2. Supply correct voltage based on specifications.
Abnormal RS485 communication	1. RS485 communication cable disconnected, short-circuited, or reversely connected. 2. Communication address, baud rate, data bit, and parity bit of the meter do not match the inverter.	1. If communication cable is faulty, replace it. 2. Set meter's communication address, baud rate, data bit, and parity bit to match the inverter's. Refer to "Parameter Settings".
Inaccurate metering	1. Cable connection is incorrect. Check phase sequence of voltage and current. 2. High and low ends of current transformer inlet are reversely connected. (If Pa, Pb, Pc values are negative, connection is incorrect.)	1. Connect cables correctly (see wiring diagrams). 2. If negative values are displayed, change current transformer cable connection to ensure correct high/low end connection.

6 Installation Verification

Check that all mounting brackets are securely installed and all screws are tightened.
Check that all cables are reliably connected in correct polarity without short circuit.

7 Customer Service Contact

Region	Country	Customer Service Contact (Email)	Tel
Europe	France	eu_inverter_support@huawei.com	0080033888888
	Germany
	Spain
	Italy
	UK, Netherlands
Asia Pacific	Australia	eu_inverter_support@huawei.com	1800046639
	Turkey	eu_inverter_support@huawei.com
	Malaysia	apsupport@huawei.com	0080021686868 / 1800220036
	Thailand		(+66) 26542662 (local call rates), 1800290055 (free in Thailand)
	China	solarservice@huawei.com	400-822-9999
	Other countries	apsupport@huawei.com	0060-3-21686868
Japan	Japan	Japan_ESC@ms.huawei.com	0120258367
Japan	India	indiaenterprise_TAC@huawei.com	1800 103 8009
South Korea	South Korea	Japan_ESC@ms.huawei.com
North America	USA	eu_inverter_support@huawei.com	1-877-948-2934
North America	Canada	eu_inverter_support@huawei.com	1-855-482-9343
Latin America	Mexico		018007703456 / 0052-442-4288288
	Argentina	la_inverter_support@huawei.com	0-8009993456
	Brazil, Chile	la_inverter_support@huawei.com	0-8005953456, 800201866 (fixed-line only)
Middle East and Africa	Egypt		08002229000/0020235353900
	UAE		08002229000
	South Africa		0800222900
	Saudi Arabia	eu_inverter_support@huawei.com	8001161177
	Pakistan		0092512800019
	Morocco		0800009900
	Other countries		0020235353900

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