TZYW Pressurized (Ex p) Brushless Synchronous Motor

The TZYW is a pressurized-enclosure (Ex p) brushless-excitation synchronous motor for stator core diameters of 1730 to 3250 mm. Wolong Nanyang developed it from imported technology and its long production of increased-safety brushless synchronous motors; its pressurization technology was the first of its kind in China.

Before start-up the purge and leakage-compensation system replaces any explosive gas inside the machine and only then releases the start. In operation it keeps the internal over-pressure, and raises an alarm or trips the supply if the pressure can no longer be maintained.

Key Specifications

Design Features

• Pressurized main enclosure with increased-safety terminal box
• Purge interlock: no start until the enclosure has been flushed
• Automatic leakage compensation and low-pressure alarm / trip
• Compact, light and efficient, with low noise, vibration and leakage

Applications

Large compressors and pumps in refineries and chemical plants, in gas, vapour or mist atmospheres of temperature class T1 - T4. Ex px versions are used in Zone 1 and Zone 2, Ex pz versions in Zone 2.

Model Code

Example TZYW(KK)2500-20/2600: TZYW = pressurized brushless synchronous motor (water-cooled; KK = air-to-air), 2500 = rated power (kW), 20 = poles, 2600 = stator core outer diameter (mm).

Explosion Protection Explained

In a pressurized enclosure ("p") the motor is first purged with clean air or inert gas and then kept at a slight over-pressure, so the surrounding explosive atmosphere cannot enter. A control unit blocks the start until purging is complete and alarms or trips if the pressure is lost. Ex px (Gb) is used in Zone 1 and Zone 2, Ex pz (Gc) in Zone 2.

Performance Data

Electrical data for the standard ratings in the TZYW catalog 0AP.138.0141a. Click a table to open it; send us the rating you need and we confirm the current data sheet.

Bearings and Lubrication

Sleeve bearings designed to ISO 11687-1, oil-ring self-lubricated or with forced lubrication (oil ISO VG 46 / L-TGA46), with insulation against shaft currents. End-shield bearings are used up to about 4000 kW, pedestal bearings above.

Up to 6500 kW self-lubrication is possible (with a high-pressure jacking-oil system above about 5000 kW when needed). Larger motors use forced lubrication from their own oil unit or from the compressor lube-oil system.

Monitoring and Accessories

• Six Pt100 sensors (three-wire) in the stator slots, two per phase, three working and three spare
• Duplex Pt100 in each bearing, for local display and remote monitoring
• Anti-condensation heaters, 220 V AC: 1000 W (1730 mm core), 1500 W (2150 mm) or 2400 W (2600 - 3250 mm) for the main machine, plus 300 W for the exciter
• Leak detector under the air-to-water cooler (cupro-nickel BFe10-1-1 tubes, pressure-tested at 1.5 × working pressure)
• Differential-protection current transformers in the main terminal box above 2000 kW
• Rotating rectifier and resistors with their own component Ex certificates; the brushless excitation system applies field smoothly at synchronisation, without shock or vibration

Purge and Leakage-Compensation Data

The pressurization system purges the enclosure before start (the start signal is interlocked until purging is complete) and then keeps the inside at least 50 Pa above the surrounding atmosphere. Purge gas: clean air or nitrogen at 0.5 - 0.8 MPa; purge volume = 5 × free volume.

Terminal Boxes

The main box is IP55 and sits on the right-hand side seen from the drive end, as do all auxiliary boxes. Standard mounting is IM 1001 or IM 7315; IM 1205 and IM 7115 (single bearing with flange) are available.

Guaranteed Performance

At rated voltage the catalog guarantees: power factor 0.9 leading, pull-out torque 1.6 × rated, locked-rotor torque 0.6 × rated, nominal pull-in torque 0.6 × rated and locked-rotor current 6.5 × rated. Noise is assessed at 85 dB(A) sound pressure. Tolerances:

All values can also be agreed project by project, for example a higher pull-in torque for a compressor with a loaded start.

Common Questions

What power range does the TZYW cover?

The TZYW covers 450 - 10,000 kW.

Which voltages are available for the TZYW?

Rated voltage: 6000 V, 10000 V. Other voltages can be checked on request.

Which explosion protection does the TZYW have?

The marking is Ex e pz II T3 Gc (standard); Ex px for Zone 1 on request. Tell us the zone, gas group and temperature class of your site and we confirm the right version.

How is the TZYW cooled?

Cooling method: IC81W (air-to-water on top); KK = air-to-air.

What is the degree of protection?

Standard protection is IP54, IP55.

Documents Supplied with the Motor

For each order we can provide the technical data sheet, outline drawing, routine test report and, for explosion-proof motors, a copy of the Ex certificate that matches the nameplate marking. Tell us in the inquiry which documents your project or your inspector requires, so they are prepared before shipment.

How to Order

For a fast, accurate quotation please send: rated power (kW), voltage and frequency, number of poles or speed, Ex marking or hazardous zone, mounting type, quantity and destination port. For a replacement, a photo of the old motor nameplate is the quickest way to match it. Lead time (about 80 days), documents and shipping are explained on our Export Service page.