Open Knife Switch
1P–3P blade disconnector to GB/T 14048.3 and IEC/EN 60947-3, [100–1500 A], central-handle operation for in-panel circuit isolation.
An open knife switch is a manually operated disconnector with exposed blade contacts, used to isolate a circuit inside a switchboard or distribution cabinet. It gives a visible break and a defined isolating point for inspection and maintenance. This unit is built to GB/T 14048.3 and IEC/EN 60947-3, in 1P to 3P versions with a central operating handle, across the [100 A~1500 A] frame range. The contacts are of open construction (IP00), so the device is mounted inside an enclosure and operated by qualified personnel. Single-throw and double-throw (changeover) versions are available.
What an open knife switch does
A knife switch connects and disconnects a circuit by driving flat blade contacts into fixed contact jaws. The open position creates a clear, visible isolating gap, which is the basis for safe isolation during maintenance. A knife switch does not provide overcurrent or short-circuit protection. In the standard isolating duty (utilization category AC-20A) it is operated without load, meaning the downstream load is switched off before the knife switch is opened or closed. Versions fitted with arc chutes are rated for on-load switching. Specify the duty when ordering so the correct version is supplied.
Highlights
- Built to GB/T 14048.3 and IEC/EN 60947-3
- Open construction (IP00) for installation inside switchboards and cabinets
- Central operating handle with single-throw on/off action
- 1P / 2P / 3P, frame ratings [100 A-1500 A]
- Visible blade break for a verifiable isolating point
- Single-throw and double-throw (changeover) versions available
Technical data
| Type designation | TPHD11 |
|---|---|
| Type | Open knife switch, single-throw (double-throw available) |
| Standard | GB/T 14048.3, IEC/EN 60947-3 |
| Utilization category | AC-20A / DC-20A (isolation, no-load); AC-22A with arc chutes |
| Rated insulation voltage Ui | 500 V AC |
| Rated operational voltage Ue | AC 380 / 400 V (DC version available) |
| Rated current In (frame) | 100, 200, 400, 600, 1000, 1500 A |
| Number of poles | 1P / 2P / 3P |
| Operating mode | Central handle (side handle / lever available) |
| Mechanical life（times） | 20,000 |
| Electrical life（times） | 6,000 |
| Contact material | Copper, silver-plated contact area |
| Insulating base | Arc-resistant insulating base |
| Protection degree | IP00 (open construction; install inside an enclosure) |
| Operating temperature | -5 °C to +40 °C |
| Altitude | ≤ 2,000 m |
| Mounting | Back-plate / panel mounting with bolts |
Open knife switches are used as main and section isolators inside power distribution boards, control panels, and industrial switchboards, where the device sits behind a cabinet door and is operated by trained staff. They are common in markets and applications that specify open-type disconnectors for cost, serviceability, and clear visual isolation, including industrial plants, utility and substation panels, pumping and irrigation control, and training or laboratory boards. The double-throw version is used as a manual changeover between two supplies, for example a mains and a generator feed.
Safety and installation note
Because the blades are exposed, this device is not for direct hand contact in service. It is installed inside an enclosure that provides the required protection against contact and ingress for the location, and it is operated only by qualified personnel following the local wiring rules. For applications that require a touch-safe, finger-proof, or outdoor-rated disconnect, an enclosed switch-disconnector is the correct selection. State the application and destination market so the suitable type is supplied.
Configuration and ordering
Specify the number of poles, the frame current, single or double throw, the operating mode (central handle, side handle, or lever), and the isolating or on-load duty. State the destination market so the correct documentation is supplied. TYPLE supplies this line through its qualified-supplier network under ISO 9001 quality control, with batch traceability and pre-shipment inspection.
FAQs
A knife switch is a type of isolating switch. It uses blade contacts to make and break a circuit and gives a visible isolating gap when open. Like other isolating switches, it provides disconnection and isolation, not overcurrent protection. The term knife switch usually refers to the open blade construction.
It depends on the version. In the standard isolating duty (AC-20A) the switch is operated without load: the load is switched off first, then the knife switch is opened. Versions fitted with arc chutes are rated to make and break load current (AC-22A). Confirm the required duty when ordering so the correct version is supplied.
Open construction means the blade contacts are exposed and the device gives no protection against contact or ingress on its own. It is installed inside a switchboard or enclosure that provides the protection required for the location, and it is operated by qualified personnel. It is not intended for direct hand access in service.
A single-throw knife switch has two positions, on and off, for one circuit. A double-throw knife switch has a centre-off position and connects the load to one of two sources, which makes it a manual changeover switch, for example between a mains supply and a generator.
It is built to GB/T 14048.3 and IEC/EN 60947-3. Conformity documents for the destination market are supplied with the order, provided through TYPLE’s qualified-supplier network under ISO 9001 quality control, with certificate references available on request.
