three phase regs

[joelea]

Hi

I am doing an electrical installer course and have 2 questions that I cannot find the answer to in any of the books.

1) Socket outlets in the same room, connected to different phases should:
a. not be connected to earth
b. never be permitted
c. be labeled 'Warning High Voltage'
d. be labeled to indicate the maximum voltage that may exist between them

2) Three phase systems are considerably more dangerous than single phase systems The EAWR and H & S safety regs state that an electrical installer

a. Must always work on three phase systems in pairs
b. Must always wear rubber boots, gloves and overalls when working on 3 phase
c. Must always know their skills, knowledge and experience limitations
d. Must always inform the local supply authority when working on 3 phase

 

[DurhamSparky]

well Q1 = d
Q2 = c

 

[joelea]

Thanks

 

[Deleted member 26818]

Nothing stopping you from wearing rubber, if that's your fancy.

 

[joelea]

i was thinking copper wire

 

[Deleted member 26818]

With rubber underneath?

 

[joelea]

overalls, obviously!!

 

[Knobhead]

Ooooohhh stop it….. Rubber! Yes mistress I’ll calm down, drool.

 

[Amp David]

Rubber overalls - AKA Gimp suit

 

[Inteificio]

being a pedantic git as ever; why the F is 3 phase ' significantly' more dangerous than 1p?
Both kill you on contact, both are very dangerous.

We are not talking 100,000v systems where 'trickery can jump significant distances to F you.

Both are 230v to earth. Only gets 400v when you are in contact with another phase in which case you are ****ed anyway.

 

[Deleted member 26818]

being a pedantic git as ever; why the F is 3 phase ' significantly' more dangerous than 1p?
Both kill you on contact, both are very dangerous.

We are not talking 100,000v systems where 'trickery can jump significant distances to F you.

Both are 230v to earth. Only gets 400v when you are in contact with another phase in which case you are ****ed anyway.

I've received shocks at both 230V and 415V, and I can assure you the 415V shock was much worse than any 230V shock I've ever had.
I accidently placed my palm across two exposed terminals on an old 3phase board, and my whole arm ached for the rest of the day, and was still giving me gip the next day.

 

[Inteificio]

About root 3 worse?

 

[hughesy]

an old spark i know was working on a 3 phase board once , and there was an almighty bang and his arm arm was seriously burnt from his finger tips to his elbow then it was off to hospital for morphine . for me 3 phase is far more dangerouse to work with, as we all know its not always possible to work with the supply isolated when working in a mains and if something goes wrong between phases then its alot worse than single phase as the flash can do enough damage to you with out even touching it.

 

[bomjac]

being a pedantic git as ever; why the F is 3 phase ' significantly' more dangerous than 1p?
Both kill you on contact, both are very dangerous.

We are not talking 100,000v systems where 'trickery can jump significant distances to F you.

Both are 230v to earth. Only gets 400v when you are in contact with another phase in which case you are ****ed anyway.

The first time you get a 400V+ belt then you will know all about it. More volts = more amps through the body and a greater chance of your old ticker losing its rhythm due to the shock. Add into that the greater energies present in of a ph-ph fault if you screw up and there is the reason.

 

[telectrix]

bloody good job we don't have 5 phase , then.