An Awful Feeling This

[gap30]

Don't get the PSCC & PEFC mixed up.

The PEFC is what you are after so you do not multiply by x 2 or 1.73 as it is a single phase calculation between a phase and earth.

230/03 = 766A

So your PEFC is 766 Amps

I hope this makes sense.

cheers pal makes a lot of sense, as i said earlier your pssc would always be higher so in my eyes its a silly question anyway

 

[brucelee]

yep always on 3 phase for single you have to measure both

 

[brucelee]

Gap30 empty your inbox for PMs mate its full

 

[gap30]

Gap30 empty your inbox for PMs mate its full

done pal

 

[gap30]

exam in two days! sheeting myself

bit of a silly one this

state two reasons for the prescribed sequence of tests prior to energising a new circuit

 

[IQ Electrical]

exam in two days! sheeting myself

bit of a silly one this

state two reasons for the prescribed sequence of tests prior to energising a new circuit

The sequence of tests is designed so that:

1 Safety is foremost-all dead tests are first and continuity of CPC is confirmed.

2 The results/faults identified in the previous test can influence the next so the sequence is designed to minimise this.

 

[gap30]

The sequence of tests is designed so that:

1 Safety is foremost-all dead tests are first and continuity of CPC is confirmed.

2 The results/faults identified in the previous test can influence the next so the sequence is designed to minimise this.

is there any reference to this in the books?

another one - state what the designer may take into account when determining maximum demand?

is this the type and use of the installation

 

[IQ Electrical]

is there any reference to this in the books?

another one - state what the designer may take into account when determining maximum demand?

is this the type and use of the installation

Diversity

 

[gap30]

a bs 1361 fuse is to be used to provide overcurrent and fault protection for a new circuit. State the effect on the operation of the fuse when the following conditions occur if the fuse was installed in the neutral conductor

a. overload fault
b. earth fault
c. short circuit fault

a. fuse would blow
b. no effect
c. fuse would blow

 

[gap30]

have i got this right, i know this has already been discussed somewhere but wanted to try it off the top of my head

sorry to be a pain in the butt

during the course of the inspection one of the single phase radial circuits supplying an item of fixed electrical equipment is to be checked for voltage drop compliance. The circuit has the following characteristics
load current = 45 amp
circuit length = 80 metres
live conductors = 10mm
a. using the information given in figure 1 determine whether the circuit meets the requirements for voltage drop. Show all calculations

80 x 1.83 x 2 x 1.2/1000 = 0.35136

v = ixr

vd = 45 x 0.35136 = 15.8 volts

230v circuit 5% = 11.5 volts

so circuit does not comply

is this correct?

 

[tony mc]

Your answer is right it does not comply.

I would have used the equation (mV/A/m)x Ib xL /1000 4.4 X 45 X 80 /1000 = 15.84 V

I see you have used (m ohms/m) x 2 x1.2 which gives you the the mV/A/m anyway.

On the question paper it will give you a table of mV/A/m for the different sizes of cables they won't expect you to remember them its the equation that you need to remember.

Good luck with the exam!!!

 

[tony mc]

And the volt drops percentages

 

[JUD]

have i got this right, i know this has already been discussed somewhere but wanted to try it off the top of my head

sorry to be a pain in the butt

during the course of the inspection one of the single phase radial circuits supplying an item of fixed electrical equipment is to be checked for voltage drop compliance. The circuit has the following characteristics
load current = 45 amp
circuit length = 80 metres
live conductors = 10mm
a. using the information given in figure 1 determine whether the circuit meets the requirements for voltage drop. Show all calculations

80 x 1.83 x 2 x 1.2/1000 = 0.35136

v = ixr

vd = 45 x 0.35136 = 15.8 volts

230v circuit 5% = 11.5 volts

so circuit does not comply

is this correct?

Yep
arty:

 

[gap30]

dont get too excited the next part of the question got me puzzled

State
i. a suitable observation to be recorded on the periodic report if the voltage drop fails to comply
ii. one action which could be taken to rectify the situation in i. above

i. circuit blah blah failed volt drop test code 2
ii. reduce length of circuit?

 

[maddfridge]

hi there

The simple answer is you are not speaking the city and guilds lingo mate and thats just it!

I have a C course qualification and i failed it first time !! 2391 that is

The simple fact then was you have a bank of questions which require a standard answer and if it aint standard you are not either !!

We just learnt parrot fashion questions and the way to answer them and at a speed which you need to get all the crap they want down
in the right time and manner.

i dont doubt you are a very good sparkie mate i would like to think i am as well as i have now got 2391 the old 2400 design and verification
qualifcation and that took its toll as well i can tell you.

get as many past paers and sit down and look for a repeat pattern over the years things may have changed new bits of regs but there are only certain areas of testing they can look at mate

the format used to 10 or 20 question short one hour and some lopnger one about two hour six i think


other on here will put me right about that so practice in short sessions to get your speed up and if at the end opf the exam you have not filled 20 or so pages you have a good chance finish early you almost certainly failed unless your a speed writer and einstein

good luck and all the best

 

[jerrybouncer]

Good luckwith your exam. Relax and you'll be fine!!

 

[gap30]

dont get too excited the next part of the question got me puzzled

State
i. a suitable observation to be recorded on the periodic report if the voltage drop fails to comply
ii. one action which could be taken to rectify the situation in i. above

i. circuit blah blah failed volt drop test code 2
ii. reduce length of circuit?

anyone?

 

[brucelee]

have i got this right, i know this has already been discussed somewhere but wanted to try it off the top of my head

sorry to be a pain in the butt

during the course of the inspection one of the single phase radial circuits supplying an item of fixed electrical equipment is to be checked for voltage drop compliance. The circuit has the following characteristics
load current = 45 amp
circuit length = 80 metres
live conductors = 10mm
a. using the information given in figure 1 determine whether the circuit meets the requirements for voltage drop. Show all calculations

80 x 1.83 x 2 x 1.2/1000 = 0.35136

v = ixr

vd = 45 x 0.35136 = 15.8 volts

230v circuit 5% = 11.5 volts

so circuit does not comply

is this correct?

Hi mate

use formulae number calculation
eg
R =m/ohm/m x 2 x mf x Lenght /1000
=1.83 x 2 x 1.2 x 80 /1000
=0.35136
= 0.35 rounded down
vd = I X R



good luck mate

 

[IQ Electrical]

1 I'd be looking at a code 3 depending on the stated manufacturers tolerances for the fixed load (525.1)

2 Go for increased conductor CSA.

 

[gap30]

just got back, long questions were a doddle, short ones i reckon i got about 5 wrong

State three conditions that must apply before the issue of a minor electrical installation works certificate 3 marks

could i feck answer that one

state the test to be carried out to ensure safety before testing the rcbo 2 marks

hummed and harred for 20 minutes this was the last question, i put Ze then scribbled it out and put PFC

anyways quite optimistic as the long questions were easy, earth fault path drawing for tn-s, resistance one, conduit and trunking inspection which i have studied to the hilt so i prob failed lol