Three Phase DC Resistance Tester

Dual Canopy Mechanic Electrical Engineering Co., Ltd. is one of the leading manufacturers and suppliers of three phase dc resistance tester in China. Please feel free to wholesale discount products for sale here and get quotation from our factory. Customized orders are welcome.

The SGZZ-3310A is a three-channel bench instrument built around the actual workload of transformer testing: three phases at once, tap by tap, day after day. It feeds current into all three windings of a star-connected transformer in a single connection, samples current and voltage independently in each phase, and puts the resistance of every phase plus the imbalance figure on one screen. For the delta side of large five-leg core units, a magnetic assist circuit borrows flux through the high-voltage winding, so a low-voltage side that used to take half a shift to charge now settles in minutes. A built-in demagnetization routine then cleans the core up before the unit goes back into service..

With the YN clamps on the star side, one connection covers all three phases. The instrument applies test current to the three windings at the same time, takes a separate current and voltage sample on each phase, and displays the three resistance values together with the three-phase imbalance rate. A converted value at your set reference temperature appears alongside, so the field record and the lab record are talking about the same number. If you turn the neutral resistance option on, the tester first measures the AO neutral lead and then runs the three-channel program; the result sits much closer to a single-phase measurement.

The delta side is where most testers grind to a halt, and that is exactly where the magnetic assist earns its keep. The instrument uses the high-voltage winding to magnetize the core and closes the flux path of the low-voltage winding, so the delta side accepts current quickly and the reading settles without the long, restless tail you know from ordinary wiring. For D or Y windings, phase-by-phase testing remains available, with the tap position and temperature editable while the current stabilizes.

Factory testing on the production line: semi-finished and finished transformers, where it exposes broken strands, loose welds, missing strands, and bad joints before the unit ships.

Handover tests after installation, comparing the fresh reading against the factory baseline to confirm the winding survived transport and commissioning.

Preventive and periodic testing in the power sector, as part of the routine check on a transformer that has been in service.

Tap-by-tap DC resistance sweeps across all OLTC positions, with the tap number written into each record.

Instrument transformers, reactors, and motor windings, anywhere an inductive resistance in the micro-ohm range needs a number.

Terminal / Part	What it does
IA, IB, IC, IO	Current input/output terminals for YN winding measurement
VA, VB, VC, VO	Voltage input terminals for YN winding measurement
Ia, Ib, Ic	Current input/output terminals for D or Y winding measurement
Va, Vb, Vc	Voltage terminals for D or Y winding measurement
Printer	Prints the resistance result and the auxiliary information
Display	7-inch color touchscreen: menus, test parameters, data log
Power switch and socket	Main power switch plus a 220V AC outlet
Grounding stud	Protective earth for the whole unit
USB port	Connects a flash drive for data export
RS232 port	Connects the host computer

Hebei Dual Canopy Mechanic Electrical Engineering Co., Ltd. sits in Baoding, in the heart of the country's transformer industry belt, and has built its business on one thing: test equipment for power equipment. We design, assemble, and calibrate the SGZZ-3310A in our own plant, and the rest of our range follows the same logic, covering transformer testing, oil testing, high voltage, and relay protection. When you order from us, the person answering your technical question has touched the machine.

Factory-direct pricing. Design, assembly, and calibration under one roof means no trading margin sitting between you and the instrument.

One-stop transformer test line-up. Turns ratio, SFRA, loss, DC resistance, oil testing. If your lab is still being built, we can fill the bench in one conversation.

Send us the test list: transformer voltage levels, typical capacity, YN or D connections, and whether you need the magnetic assist on a regular basis.

We confirm the configuration (current gears, interface language, lead length) and send a quotation within one working day.

Production and calibration run in our plant; you get the pre-shipment test report before the unit leaves.

Delivery by express, sea, or rail as you prefer, with the manual, test leads, and certificate in the carton.

After arrival we stay on the line for operation questions, and the warranty covers the unit from the day it lands.

📞 Pre-sales Hotline: [+8613603329412]

📧 Email: [dylan@dualcanopy.com]

💬 24-Hour Online Response

Q1: Can one machine really cover both three-phase and single-phase work?
Yes. The three channels handle a YN winding in a single connection, and the single-phase gears (up to 10 A) let you test any winding of any connection phase by phase, without reversing the test line.

Q2: What does the neutral resistance option change?
With it on, the instrument measures the AO neutral lead resistance first, then runs the three-channel test. The final three-phase data sits much closer to what a single-phase method would produce.

Q3: How long does a full three-phase test take?
It depends on the winding inductance. On large low-voltage sides with the magnetic assist engaged, the current settles in minutes; the screen shows the live current, so you know exactly when the value is stable.

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