Isolators & Switch Disconnectors

Rail Electrification & Cable Equipment LV HV

Craig & Derricott

Switch Disconnectors & Isolators

T&D Link-Up Registered Supplier ID: 158366 

 

 

 

Switch Disconnectors or Isolators provide the means to safely disconnect an item of electrical equipment from the power supply. Craig and Derricott isolators are primarily designed to provide a means of local isolation when an elecrical item may need maintenance or repair, an isolator (or switch disconnector) has to comply with the following minimum requirements:-

• Provide an effective clearance between the supply and the load appropriate to the voltage applied.
• Provide a means of locking in the 'Off' position. (Padlocking)
• Provide a true indication of the contact state.
• Provide a safe disconnection from the supply even under fault conditions.

Craig & Derricott's Switch Disconnectors (Isolators) meet, and often exceed, the above requirements making each, the product of choice in today's market.

Pictured: Craig & Derricott Switch Disconnectors And Isolators

Fuse Combination Units

Sheet Steel Enclosure

• 32A to 630A
• Designed to accept ‘bolted tag’ style BS88 fuse links
• Two all metal handle sizes
• Interiors - 3 pole + switched neutral • Sealing to IP65
• Lockable in ‘Off’ with option for adding ‘On’ position
• All external surfaces are finished with an LUL certified paint system.

Switch Disconnectors

Sheet Steel Enclosure

• 25A & 40A
• External mounting feet
• External earth
• Sealing to IP65
• Lockable in ‘On’ & ‘Off’ positions
• All external surfaces are finished with an LUL certified paint system.

Stainless Steel Enclosure

• 25A & 40A
• External mounting feet
• External earth
• Sealing to IP65
• Lockable in ‘On’ & ‘Off’ positions
• 18 swg Grade 304 stainless steel

Sheet Steel Enclosure

• 40A to 400A
• Five enclosure sizes across the range
• Two all metal handle sizes
• Interiors - 3 pole + switched neutral
• Sealing to IP65
• Lockable in ‘Off’ with option for adding ‘On’ position
• All external surfaces are finished with an LUL certified paint system

Craig & Derricott is well known for producing semi-standard products such as the 'Section 12' approved isolators but they are equally responsive to engineer small scale items. 

Pictured: Craig & Derricott Products Developed For Underground Use

Craig & Derricott Switch Disconnectors for London Underground (LUL)

Following the Kings Cross fire of 1987, the resulting Fennell enquiry prompted the introduction of additional fire precautions for 'Sub-surface Railway Stations'.

These additional requirements were introduced under Section 12 of the Fire Precautions Act 1971, and since then have been known simply as Section 12 regulations. There are at present around 120 London Underground stations that come under Section 12 requirements.

The forensic report on the fire sited several instances of a 'flash over' effect caused by materials and paint finishes being ignitable. Exacerbating the conditions underground were toxic fumes given off by certain materials being excessively heated.

Although the new regulations dealt with all aspects of fire prevention such as the removal of wooden escalators, the installation of heat detectors, improved staff training etc, as far as actual equipment supplied for underground use, the overriding emphasis was on materials and paint finishes.

With this isolation range of Craig and Derricott Switch Disconnectors (Isolators), the overall consideration has been to meet, and where possible exceed, the Section 12 requirements. This has been achieved by the careful selection of individual component materials and the use of only recognised and approved paint finishes.

Craig & Derricott Section 12 low voltage (LV) electrical isolators are suitable for London Underground applications.

T&D UK can offer competitive prices and deliveries on the complete range of Craig and Derricott Switch Disconnectors, including 25amp isolators, 40amp isolators, 63amp isolators, 80amp isolators, 100amp isolators, 125amp isolators, 160amp isolators, 200amp isolators, 250amp isolators, 315amp isolators and 400amp isolators (switch disconnectors) with LUL London Underground Section 12 approval.

Pictured: Craig & Derricott AC Isolator

Craig & Derricott Switch Disconnectors Catalogue