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Power/works list: Difference between revisions
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cable colour codes
(cable colour codes) |
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===Sub-distro boxes=== | ===Sub-distro boxes=== | ||
* One to be fitted on outside wall of office, marked [CU] | * <s>One to be fitted on outside wall of office, marked [CU]</s> | ||
* <s>One to be fitted on outer wall of wet lab/biolab, marked [CU]</s> | * <s>One to be fitted on outer wall of wet lab/biolab, marked [CU]</s> | ||
** Use 2.5mm T+E from this box to service horizontal line of sockets in biolab at approx 1m height from floor and 24cm spacing | ** Use 2.5mm T+E from this box to service horizontal line of sockets in biolab at approx 1m height from floor and 24cm spacing | ||
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*** Fit female conduit ends to back boxes before installation, cut 8x 24cm lengths of conduit and build socket line on floor. Hold to wall to mark screw positions. Drill and fit. | *** Fit female conduit ends to back boxes before installation, cut 8x 24cm lengths of conduit and build socket line on floor. Hold to wall to mark screw positions. Drill and fit. | ||
*** Ring should be wired on alternate boxes for preference. Ensure earth sleeving is used, especially on short earth leads to boxes. | *** Ring should be wired on alternate boxes for preference. Ensure earth sleeving is used, especially on short earth leads to boxes. | ||
===Cable Colour Codes=== | |||
* Once upon a time the colour codes in the UK were ''black'' neutral, ''green'' earth, ''red'' live - phase 1, ''yellow'' and ''blue'' other two live phases when using a 3-phase supply. | |||
Then along came "European Harmonization" and everything changed. In your home "''red-black-green''" became "''brown-blue-green/yellow''" and it wasn't too bad. But in the three-phase world the primary (and easily identifiable) red-yellow-blue became "''brown-grey-black''" which don't look much different in the semi-dark. Yes, black was now a *live* wire, not neutral. And yea, electricians up and down the land of the Angles got most distraught. Especially when they were laying steel-wire-armoured (swa) cables. | |||
* At the London Hackspace we have a mix of old and new cables, used for a mix of purposes, because we try to reuse everything to reduce expenditure. This means that you must always '''check''' what a wire is being used for and NOT trust the original colour. | |||
*Where the original colours are '''red-yellow-blue''' and it is now carrying single phase then '''red=live, blue=neutral, yellow=earth''' | |||
*Where the original colours are '''brown-black-grey''' and it is now carrying single phase then '''brown=live, black=neutral, grey=earth''' | |||
Tape will usually be used at each end of the cable to correctly identify the use. | |||
===Phase allocation=== | |||
* We have a three-phase supply and need to keep our consumption on each phase roughly equal. | |||
* This means that different areas, even if adjacent, may be on different phases. '''Do NOT use extension leads from one area to feed equipment in another'''. | |||
;Remember - NEVER CROSS THE PHASES! | |||
