Pick Ya Brains

[DanTheMainsMAn]

have you got any pics of 3 phase boards or set ups

 

[DanTheMainsMAn]

im on college holidays and wondering about 3 phase so i know a bit about it from some professionals

 

[Steve]

Why sorry? Whats the score, are you still at school, just enquiring etc?

sorry for calling everyone a t**t i expect.

i do have more pics, i will post them as thumbnails here, i dont want to slow down other people's computers if they choose not to look at them.

this is under the board i photographed above. the electric meter and 3 phase head are visible, along with a couple of sangamo timers, used to control the outside lights and a contactor for some fridges which go off overnight. the chunky armoured cable on the right exits to the street (this is in a cellar, hence it goes up to 3 foot deep)


a smaller distribution board, which was added on last year, and is fed by the 3 phase MCB marked "DB2" in the first DB. That loop of armoured cable links them together.


2 no. 4 pole contactors. one of them controls the pop fridges and beer fridges, along with the water heater and oil rads in the office. this one is controlled by one of the timers below the DB. The other contactor is for the 4 rows of shop lights, which are then controlled by a single secret keyswitch at the front door. the 2 armoureds that you see there go of to feed 2 small compressors for an air con and a coldroom. the 2 at the top (one to the metal box, one to the rhs DB) feed the 2 big 3 phase air con units. The one that goes to the metal box used to go to the RHS DB before the second one was added. They used its 3 ph MCB space to feed the second DB.

 

[DanTheMainsMAn]

if you got any other pics it is interesting looking and understanding them thanks m8

 

[DanTheMainsMAn]

So how is on the Big DB First 1 how are the first 4 R,Y,B,R Connected to contactors then switches and lights dont get it.

 

[Steve]

thats yer lot. unless you want to see the front of a C63 3 phase MCB that controls all this lot (anyone know why this might have been chosen over a plain main switch?). You can see it in the first picture above anyway. i'm not brave / qualified enough to take the cover off the front - theres 415V lurking in there. (by the way, when people say 415V, they MEAN 230V 3 phase. the RMS sum (or something) of the 3 phases at 50Hz is 415V when you do the maths)

i really am going to see about becoming qualified one day . . .

 

[Steve]

So how is on the Big DB First 1 how are the first 4 R,Y,B,R Connected to contactors then switches and lights dont get it.

the top MCB is for the first row of lights (it goes through one of the "controllED" poles of the contactor). also on that MCB is the power supply for the switch that operates the contactor coil. the contactor is basically a fancy relay that uses an electromagnet to switch multiple outputs. it consumes very little current, a few watts, so it can be bunged onto any circuit really.

the other 3 MCBs are just the other 3 rows of lights which go to the other 3 poles of the contactor.

 

[DanTheMainsMAn]

so what would happen if you had 5 rows of lights

 

[Spark123]

My guess is the individual phases are fed through the four contacts of the contactor providing the switch circuit and the control circuit which operates the coil on the contactor is also fed from R1. This is all well and good until one day a lamp on row 1 goes pop and the whole lot go off!!! (I suppose this could happen on the contactor etc failing also)

so what would happen if you had 5 rows of lights

You'd need another contactor.

 

[RF Lighting]

One with the cover off:

Its like electrical po*n!

 

[DanTheMainsMAn]

lol

 

[DanTheMainsMAn]

you got any other pics of 3 phase RF Lighting

 

[Spark123]

I take it you were installing the RCBOs RF? Noticed the isolators are open. Look at them tiddly 3 phase wires!!!

 

[DanTheMainsMAn]

how do you wire them RCBO's up them anyone and are they just rcds built into mcbs

 

[JohnD]

Look out! RCBO alert!