Current Job

[kme]

Managed to spook myself today!

Rewiring hotel corridor lighting - corridors 40M in length, arranged in a square. all lights 12v MR16, plus some EM fittings (non- & maintained).Approx 25 no. fittings & 8 no. EM`s per corridor. 2 floors.

The supply DB is (almost) in a corner of 2 corridors; so the two corridors nearest were being redone in 1.5mm/1.0cpc, and the furthest in 2.5/1.5.

The new DB & breakers arrived today - 10A "C" curve ( for the tx. inrush surge).

But the 2.5/1.5 run has an r1r2 of 1.9ohms, and the supply position Zs os 0.16. Max Zs for 10A "C" is 1.85ohms. Arrrrrrgh!!!!!!!

Going to have to use 6A "C" instead - or 10"B"`s. We`re not doing design, just construct & I&T -

Thought I`d have to do some drastic rewiring work.

Problematic, as they`ve only allowed 4 weeks for the whole lot; and 3 weeks tomorrow I`m off out of the country for my wedding anniversary.

PLUS call today to 2nd fix a domestic, and a 2 day job in the offing. Needs more hours in a day for a week or two, if nobody mindsGuiness DrinkGuiness DrinkGuiness Drink

KME

 

[SLIPSHOD & SLAPDASH]

Run an extra Cpc with the Tw &e

 

[kme]

Considered that - also moving the location of the new sub-board, and supplying it on 10mm or 16mm feeds. But, as said, I`m not designer on this job. Report back to head contractors, who suggested downgrade MCB`s.

Besides. seperate cpc into all those JB`s - time intensive. I`m just going to measure out and do the calcs for the other corridors BEFORE I wire `em!!!!!

 

[SLIPSHOD & SLAPDASH]

You could use up that old drum of 4 or 6mm earth left over from the 16th and connect it to just the far end of the circuit.

 

[NozSpark]

Why not just run out a 4mm or 6mm sub main??

 

[kme]

No location for it mate. Boards have to be in 1 room downstairs. Design spec.