Suitable Wiring System For Light Circuits

[paulthemagpie]

hi guys,

just for my assignment for college could you point me in the right direction.

Select a suitable wiring system for the lighting circuits within the electrical switch room and stores?

now they like 50 twin floresent 1800 x 2x70w lighting on this circuit.

thanks guys! dont know what i would do without you

 

[paulthemagpie]

is this getting at selecting the right cabling, for example would it be hot within this building?

or would it still be basic cable

 

[DPG]

Galv conduit system since it's a stores environment and may well get knocked? Daz

 

[paulthemagpie]

what about the wiring? still 70oc themo

 

[paulthemagpie]

thanks for the advice so far guys, but what about the actual cabling. If we use galv conduit can we just use basic cabling as we already protected

 

[paulthemagpie]

the other thing is would we have all these on 1 circuit breaker or would we need to split them onto maybe 2 or 3 circuits?

 

[paulthemagpie]

am i on the right track with the mcb for this circuit.

if the twin flor were 2 x 70w and they 51 of them then to work out what mcb we would need is

2 x 70 x 51 = 7140w + 750w for some outside light = 7890 then divide by 230 to give 34.3a

would we then be better having 1 mcb or maybe splitting

 

[DPG]

Is this the same question as last time? 50 lights all on 1 breaker means a lot of darkness if ever there is a fault. Daz

 

[Richard Burns]

For fluorescents on a B type breaker you want to multiply by 1.8 to get a suitable current rating on the MCB, you also need to consider division of circuits to avoid nuisance.
Maximum breaker for lighting circuits should be 16A.
Temperature should not be a problem, if you are cabling in a switch room you need to ensure that the system is protected for the highest voltage present.

 

[paulthemagpie]

is the 16a max as per the regs?

if so using 90% diveristy we could get away with 2 x 16a

is this right

 

[One_of_them]

For fluorescents on a B type breaker you want to multiply by 1.8 to get a suitable current rating on the MCB

this is a must if using switch start/choke fittings. I believe if using HF fittings this is not required

I would defo suggest splitting otherwise if the lights trip your in complete darkness as suggested above.

After deciding on splitting circuits, determine loads required and size cables according to breaker selected.

 

[paulthemagpie]

the onsite guide suggested type c

 

[Richard Burns]

559.6.1.6 if using bayonet or edison screw lamps max rating is 16A. Type C is suitable for fluorescent banks.
I would tend to aim for about four circuits for the lighting.