The Katko KEM 280VV M3 2 x 63A Changeover Switch provides a durable and dependable solution for manually switching between two electrical power supplies.
Designed for commercial, industrial and suitable building installations, it allows controlled power source selection while helping prevent unintended connection between alternative supplies when correctly installed.
Whether you're installing a backup power arrangement, upgrading electrical distribution equipment or managing alternative supply connections, this enclosed changeover switch offers reliable performance in a compact design.
Its 2 x 63A AC-23A rating at 415V makes it suitable for appropriately designed electrical installations requiring dependable load switching.
The robust polycarbonate enclosure provides excellent electrical insulation while protecting internal components against moisture, dust and demanding environmental conditions.
With an IP66 protection rating, the switch is dust-tight and resistant to powerful water jets, making it suitable for many indoor and outdoor installations where appropriate mounting and cable entry arrangements are provided.
The UV-resistant enclosure also offers good resistance to sunlight and many chemicals, helping maintain durability in challenging environments.
For added safety, the switch features a padlockable operating handle, allowing the selected position to be secured against unauthorised operation during maintenance.
Its door interlocking mechanism helps restrict access to internal electrical components, supporting safer servicing and inspection procedures.
The self-extinguishing enclosure material provides additional protection in demanding electrical installations.
Despite its robust construction, the switch remains compact, measuring just 144 mm wide, 190 mm high and 96 mm deep, making it convenient for installations where mounting space is limited.
Manufactured in Finland as part of Katko's IsoSafe range, the KEM 280VV M3 combines practical safety features, durable construction and dependable switching performance.
For electricians and electrical contractors requiring a robust manual changeover solution, the Katko KEM 280VV M3 offers reliable power source selection, secure operation and IP66 environmental protection in one compact enclosure.
Key Features
- 2 x 63A Changeover Switching – Designed for manual selection between two electrical supplies.
- IP66 Protection – Dust-tight enclosure with protection against powerful water jets.
- Durable Polycarbonate Enclosure – Strong, electrically insulating construction for demanding environments.
- UV and Chemical Resistance – Suitable for many indoor and outdoor installation conditions.
- Padlockable Operating Handle – Helps prevent unauthorised switching during maintenance.
- Door Interlocking Mechanism – Helps restrict access to internal components during operation.
- Self-Extinguishing Material – Supports improved safety in electrical installations.
- Compact M3 Enclosure – Measures 144 x 190 x 96 mm for space-efficient mounting.
- High Mechanical Endurance – Rated for 50,000 mechanical operations.
- Load Break Switching – Suitable for switching loads within its specified utilisation ratings.
- Wide Terminal Compatibility – Accepts suitable copper conductors from 2.5 to 35 mm².
- Finnish Manufacturing – Designed and manufactured in Finland as part of the Katko IsoSafe range.
Technical Specifications
- Brand: Katko
- Product Range: IsoSafe
- Model: KEM 280VV M3
- Product Number: 32069
- GTIN: 6419410320693
- Product Type: Enclosed Manual Changeover Switch
- Switch Type: Load Break Switch
- Rated Operational Current AC-23A at 415V: 63A
- Rated Operational Current AC-22A at 415V: 80A
- Rated Operational Current AC-21A at 415V: 100A
- Number of Poles: 2
- Rated Insulation Voltage (Ui): 800V
- Rated Impulse Withstand Voltage (Uimp): 8kV
- Rated Thermal Current (Ith): 100A
- Rated Short-Time Withstand Current (Icw): 2kA for 1 Second at 690V
- Rated Short-Circuit Making Capacity (Icm): 2.5kA at 690V
- IP Rating: IP66
- Enclosure Material: Polycarbonate
- Enclosure Type: M3
- Colour: Grey/Black
- Width: 144 mm
- Height: 190 mm
- Depth: 96 mm
- Net Weight: 1.1104 kg
- Copper Terminal Capacity: 2.5–35 mm²
- Maximum Terminal Tightening Torque: 2.5 Nm
- Mechanical Endurance: 50,000 Operations
- Country of Manufacture: Finland
- Download Technical Datasheet (PDF)
Note: Electrical current ratings depend on the applicable utilisation category and operating voltage.
Installation and circuit protection must be selected according to the manufacturer's technical documentation and applicable electrical regulations.
Suitable Applications
- Manual switching between alternative electrical power supplies.
- Suitable backup generator changeover installations.
- Commercial and industrial electrical distribution systems.
- Electrical installations requiring secure manual power source selection.
- Indoor and outdoor installations requiring IP66 enclosure protection.
- Machinery and equipment power supply arrangements.
- Building electrical systems incorporating alternative supplies.
- Maintenance applications requiring a padlockable switch.
Frequently Asked Questions
Can the Katko KEM 280VV M3 be used with a backup generator?
Yes, the Katko KEM 280VV M3 can be used in suitably designed generator changeover installations where its electrical ratings and switching configuration meet the system requirements.
A correctly installed changeover switch allows selection between the normal electricity supply and an alternative source, such as a generator.
However, generator compatibility depends on factors including voltage, current, earthing arrangements and the required switching of live and neutral conductors.
A qualified electrician must confirm that the switch is appropriate for the intended installation and that the two supplies cannot be connected together incorrectly.
Does this switch automatically change power sources during an outage?
No, the KEM 280VV M3 is a manually operated changeover switch.
It requires someone to operate the handle to select the required power source.
The switch does not automatically detect a power failure, start a generator or transfer electrical loads without manual intervention.
Installations requiring automatic power transfer need a suitable automatic transfer switching system.
Can the KEM 280VV M3 be installed outdoors?
Yes, its IP66-rated polycarbonate enclosure is designed to provide a high level of protection against dust and water ingress.
The enclosure is also resistant to UV radiation and many chemicals, making it suitable for a wide range of outdoor and demanding environmental conditions.
However, the IP66 rating depends on correct installation, including suitable cable glands, sealed cable entries and appropriate mounting arrangements.
For particularly exposed locations, additional protection may be advisable according to the manufacturer's installation guidance.
What does the 2 x 63A rating mean?
The 2 x 63A designation identifies the changeover switch arrangement, with two supply switching paths rated at 63A under the specified AC-23A conditions at 415V.
It does not mean the switch provides a combined 126A output or that both electrical sources can supply the load simultaneously.
The device is intended to select between alternative supplies, with the electrical load limited by the applicable switch rating and system design.
Because current ratings vary according to utilisation category, the installation must be assessed using the appropriate manufacturer's electrical specifications.
Does the padlockable handle make the switch suitable for maintenance isolation?
The padlockable handle helps prevent unauthorised operation while maintenance or servicing work is being carried out.
This can support safe isolation procedures when the switch is correctly installed and used within its specified ratings.
However, the handle alone does not guarantee that equipment is electrically safe to work on.
Electrical workers must follow appropriate isolation procedures, including securing the supply and verifying that the relevant circuits are de-energised before beginning work.
Can I connect a single-phase or three-phase supply to this switch?
The KEM 280VV M3 is a two-pole changeover switch, so its suitability depends on how the electrical supply conductors need to be switched.
It may be suitable for certain single-phase arrangements where two conductors require switching, subject to the system design and applicable regulations.
A conventional three-phase installation will generally require a switching arrangement with additional poles to accommodate the necessary conductors.
A qualified electrician should confirm the required pole configuration, neutral switching arrangements and electrical ratings before selecting the device.