SUWI-120 Series for Substations

SUWI-120 — the Substation Wizard

The SUWI-120 series is a versatile test instrument specifically developed for evaluating power and control apparatus in substations. The instrument combines four essential test functions in one device: relay timing, turns ratio, contact resistance measurement and circuit breaker timing. Additionally, MCBs and other protection components can be tested.

Weighing just 10.7 kg with IP67 protection and an operating temperature range of -10 to +60 °C, the SUWI-120 is designed for intensive field use — from substations and distribution networks to industrial switchgear installations.

Applications

• Substations and high-voltage networks — periodic inspection and maintenance of power circuit breakers, protection relays and power transformers
• Distribution networks — turns ratio measurement and relay timing on distribution transformers and switches
• Industrial installations — contact resistance measurement and circuit breaker timing on factory distribution systems
• Commissioning — relay timing, breaker timing, contact resistance and turns ratio when commissioning new switchgear and transformers
• Fault analysis — check relays, switches and transformer turns ratio with one instrument
• Current and voltage transformers — turns ratio, phase angle and polarity test on CTs and PTs

Four test functions in one instrument

Relay timing

The SUWI automatically tests over-current, over-voltage, directional overcurrent and frequency control relays. With an adjustable output current up to 110 A AC / 120 A DC and output voltage up to 150 V AC / 220 V DC. Four universal input modules for flexible measurement configurations.

Turns ratio measurement

Using the measurement method of ANSI/IEEE C57.12.90, the SUWI performs transformer ratio measurements with a precision of 0.08% across a range of 0.8 to 10,000. Measures phase angle, polarity and ratio error. Generates test voltages of 1, 4, 10, 40 and 100 V AC for current, voltage and power transformers. Need a wider ratio range, or winding resistance and heat run? Choose the TRAN-203.

Contact resistance measurement

With an adjustable DC current up to 120 A, the SUWI measures the contact resistance of circuit breakers, shunts and disconnectors. Measurement range up to 5 Ω with a resolution of 0.01 µΩ. Including Auto Test mode.

Circuit breaker timing

Three-phase circuit breaker timing tests determine switching performance: OPEN, CLOSE, OPEN-CLOSE, CLOSE-OPEN and OPEN-CLOSE-OPEN — simultaneously on all three phases. Including coil current measurement with internal and external trigger functions. Timing windows: 1 s, 10 s, 20 s. Timing accuracy: 0.05% of reading ± 0.1 ms. Need motion analysis? See the CIBRE-30.

Key features

• 4 test functions in 1 instrument — relay timing, turns ratio, contact resistance and circuit breaker timing
• Relay timing — up to 110 A AC / 120 A DC, 150 V AC / 220 V DC, 4 universal inputs
• Turns ratio — 0.8 – 10,000, precision 0.08%, method per ANSI/IEEE C57.12.90
• Contact resistance — up to 120 A DC, 0.01 µΩ resolution, 5 Ω range
• Circuit breaker timing — 3-phase, O/C/O-C/C-O/O-C-O, coil current measurement
• 7″ IPS touchscreen — 1024 × 600 pixels
• DMP software — PC software for data analysis and reporting via USB or Ethernet
• IP67 enclosure — fully dust and waterproof, 10.7 kg
• Operating temperature — -10 °C to +60 °C, 95% RH
• Communication — USB 2.0, Ethernet
• Internal memory — for test result storage
• Power supply — 100–240 V, 47/63 Hz
• Made in UK — HighTest Technology

DMP software

The SUWI-120 is supplied with DMP software (HighTest) for transferring, analysing and reporting test data via USB or Ethernet. The software provides structured display of all measurement results including graphs and automatic report generation.

Also available for rental

The SUWI-120 is available for both purchase and rental from IONIO. Ideal for temporary projects, periodic maintenance or evaluating the instrument before purchase. The rental SUWI-120 is supplied with all test leads, calibrated and ready to use. Contact us for availability and rates.

When to choose the SUWI-120 or separate instruments?

The SUWI-120 replaces four separate instruments: a relay tester, a turns ratio meter, a contact resistance meter and a circuit breaker timer. This saves transport weight, setup time and cost. For dedicated circuit breaker timing with 6 contacts, see the CIBRE-L6. For contact resistance measurement up to 200 A with static and dynamic measurement, see the ARES-200D.

Complete substation test set

For commissioning, maintenance and fault analysis in substations, combine these instruments:

• TRAN-203: transformer analysis. Turns ratio up to 50,000, winding resistance up to 20 A DC, OLTC and heat run.
• SUWI-120: four tests in one case. Relay timing, turns ratio, contact resistance up to 120 A and 3-phase breaker timing.
• CIBRE-30 and CIBRE-60: circuit breaker analysis with motion analysis, 3 or 6 contacts.
• CIBRE-L3: compact 3-contact breaker timer with printer.

The TRAN-203 and the SUWI-120 are also available for rent.

Read also: measurements and tests with the SUWI-120.

Technical Specifications

Measurement Parameters

• Relay Timing Tests (overcurrent relays, overvoltage relays, directional overcurrent relays, frequency control relays)
• Turns Ratio Measurement, Phase Angle, Polarity, Ratio Error (%)
• Contact Resistance / Low Resistance Tests (circuit breaker contact resistance and shunt resistance)
• Circuit Breaker Timing Test (3-phase circuit breaker timing tests: open, close, open-close, close-open, open-close-open; coil current measurement; internal and external triggers)

Relay Timing Measurement Features

• Output currents: up to 110 A AC (magnitude and frequency adjustable); up to 120 A DC
• Output voltages: 150 V AC (magnitude and frequency adjustable); 220 V DC
• Universal input module: 4 inputs; binary wet/dry
• Voltage measurement range: up to 300 V AC/DC

Turns Ratio Measurement Features

• Ratio measurement modes: CT mode; PT mode (single-phase and three-phase)
• Test voltages:

  • CT mode: 1 V and 4 V

  • PT mode: 1, 4, 10, 40, and 100 V

• Ratio range: 0.8 – 10,000

Contact Resistance Features

• Measurement modes: static resistance measurement
• Auto Test Mode: yes
• Test current: up to 120 A DC
• Measurement range: up to 5 Ω

Circuit Breaker Timing Measurement Features

• Measured parameters: contact timing (O, C, O-C, C-O & O-C-O); coil current measurement; internal and external triggers
• Timing windows: 1 s, 10 s, 20 s
• Timing accuracy: 0.05% of reading ± 0.1 ms
• Contact detection: yes
• Trigger input voltage: 24 – 300 V DC or AC peak
• Breaker initiation capacity: 20 A, 300 V DC or AC peak
• Initiation current measurement range: 0 – 20 A DC, 5 kHz

General Properties

• Power supply: 100–240 V, 47/63 Hz
• Internal memory: yes
• Communication: USB 2.0/1.1 Standard-B, Ethernet
• PC software: DMP Software
• Display: 7-inch IPS touchscreen, 1024×600 pixels
• Dimensions: 429 × 328 × 236 mm (16.9 × 12.9 × 9.3 in)
• Weight: 10.70 kg
• Temperature: operating –10 °C to +60 °C; storage –30 °C to +70 °C
• Humidity: 95% RH, non-condensing
• Protection class: IP67 (with lid closed)

Included accessories

• 5 × 5 m input cables (red)
• 5 × 5 m input cables (black)
• 2 × 3 m contact cables (white)
• 2 × 3 m contact cables (blue)
• 1 × 2.5 m current cable (red)
• 1 × 2.5 m current cable (black)
• Power cable
• Grounding cable
• USB cable
• Ethernet cable
• USB stick
• Manual (digital version)
• DMP software
• Cable bag

Optional accessories

• 5 m measuring cable set for TURA-01
• TURA-01 cable set adapter
• CIBREL3 cable set adapter
• 6 m contact cable set for contacts 1, 2 & 3