Overview
The GW5 is a double-post, V-type horizontal-rotation outdoor AC high voltage disconnector for three-phase 50 Hz networks. It isolates high voltage during equipment and line maintenance to keep work safe; it cannot break load or short-circuit current and is used together with a circuit breaker — when de-energising open the breaker first and then the disconnector, when energising close the disconnector first and then the breaker.
Each pole is built from a base, two support-post insulators, outgoing terminals and contacts. The two insulators are set at a 50° included angle on bearings at the ends of the base and stand perpendicular to it; the main conducting part is carried above the two posts and rotates through about 90° with them to open or close the circuit. A pollution-proof version is available for heavily polluted areas.
Model Designation
The type is designated G W 5 -12 / □ □ and decoded as follows:
- G — disconnector
- W — place of use: outdoor
- 5 — design sequence number
- 12 — rated voltage in kV
- □ — rated current in A
- □ — rated short-circuit withstand current in kA
Construction and Operation
- Double-post V-type poles. Two support-post insulators per pole incline toward each other at a 50° angle and rotate the knife contacts through about 90°, giving a wide, clearly visible break.
- Current path. Base, support-post insulators, outgoing terminals and contacts form the main conducting circuit; contact pressure is maintained by the self-cleaning finger contacts.
- Manual or motorised mechanism. The poles are coupled by a three-phase linkage and driven by a manual or motorised operating mechanism (as in the outline drawing), with open / close position indication on the motorised version.
- Pollution-proof design. Extended-creepage insulators are offered for severely polluted coastal and industrial regions to prevent pollution flashover.
Technical Parameters
Rated Parameters
The GW5 series is rated for three-phase AC 50 Hz networks. Rated voltage options covered here are 40.5 kV, 72.5 kV and 126 kV. Rated current, rated short-time withstand current, rated peak withstand current and the power-frequency / lightning-impulse withstand voltages are fixed by the technical agreement and follow the equipment nameplate.
Normal Service Conditions
- Altitude: 1000 to 3000 m
- Ambient temperature: not above +40℃ and not below −30℃ (−40℃ for cold areas)
- Wind pressure: not exceeding force 8
- Seismic intensity: not above intensity 8
- Vibration: no frequent violent vibration at the installation site
- General type: installation site free from gases, vapours, chemical deposits, salt mist, dust or other explosive or corrosive substances that seriously affect insulation and conductivity
- Pollution-proof type: suitable for heavily polluted areas, free from substances that may cause fire or explosion
Installation & Wiring
Installation and Mounting
Assemble the V-type poles on the common frame at the specified phase spacing (A), fix each base through the four Φ20 mounting holes on the C / D span, and couple the poles to the operating mechanism with the three-phase linkage shaft. Keep at least 1100 mm clear below the mechanism for the operator platform and allow the 500 mm terminal offset shown on the outline drawing. Verify free ~90° travel, correct contact seating and the full visible break before energising, and bond the bases to the earth grid.
Outline Dimensions by Rated Voltage
| No. | Rated voltage (kV) | A | A1 | H | E | C | D |
|---|---|---|---|---|---|---|---|
| 1 | 40.5 | 1200 | 1075 | 1070 | 1400 | 240 | 300 |
| 2 | 72.5 | 1600 | 1285 | 1295 | 2200 | 240 | 300 |
| 3 | 126 | 2000 | 1660 | 1695 | 3000 | 240 | 300 |
All dimensions in mm and correspond to the outline drawing (A = phase spacing, A1 = V opening width, H = height, E = mechanism-centre distance, C / D = base mounting-hole span). Mounting holes 4 × Φ20.
Selection & FAQs
Selection Guide
- Choose the rated voltage (40.5 / 72.5 / 126 kV) to match the network; phase spacing and pole height increase with voltage.
- Specify the rated current and withstand ratings to match the feeder duty (per technical agreement).
- Select manual or motorised operation; the motorised mechanism gives remote operation with position indication.
- For heavily polluted sites order the pollution-proof version with extended-creepage insulators.
Frequently Asked Questions
Q1: Can the GW5 break load or short-circuit current?
No. It is an isolator only: it opens and closes no-load circuits and provides a visible break for maintenance. Load and fault currents are cleared by the associated circuit breaker.
Q2: What is the correct operating sequence with the circuit breaker?
When de-energising, open the circuit breaker first and then the disconnector; when energising, close the disconnector first and then the circuit breaker.
Q3: What does the double-post V-type design mean?
Each pole uses two support-post insulators set at a 50° included angle; the knife contacts on top rotate through about 90° with the posts to open or close the circuit, giving a clearly visible break.
Q4: What voltages does the series cover?
The outline dimension table covers 40.5 kV, 72.5 kV and 126 kV; the type designation GW5-12 shows the format with the rated voltage in kV.
Q5: What are the service conditions?
Altitude 1000 to 3000 m, ambient temperature −30℃ (−40℃ in cold areas) to +40℃, wind up to force 8, seismic intensity up to 8, and no frequent violent vibration.
Q6: Is a motorised version available?
Yes. The poles can be driven by a motorised operating mechanism through the three-phase linkage, with open / close position indication; a manual mechanism is the standard option. See the disconnector range for related models.