Firstly I just want to say that working from tables and on site guides can be great for convenience, and this is good. But so often the very presence of these easy and convenient rules of thumb to comply with regulation may prevent a person from developing a deep technical understanding of why...
Hello all,
i posted this in the electrical theory section but with no responses I thought I would post here as well - since originally posting I have spoken to ELECSA and they have basically said I can use any basis I want to calculate diversity so long as I document what I used and why which...
Hi, I currently am working on some cable sizing calculations for an exercise in which we apply our knowledge and use of the OSG. We have a ficticious single-phase, light commercial installation for which we have designed the circuits to supply a range of requirements and loads. We have selected...
So luckily I am now onto the design module and by chance a friend asks if it is possible to change her LPG gas hob for an electric one, existing oven circuit is fed by 32amp MCB, 6mm T&E normally clipped with no insulation, 15m run.
Existing double oven is 5.5kw full load and the proposed hob...
Hi All,
Wondering if any of you could help...
I am currently pricing up a Nursing home extension and the easiest method to get a supply including the cheapest is for me to run a 16mm 3 core SWA from the existing care home to the extension which is approx 85 metres. The supply will be fed from...
Hey all,
To calculate the resistance of the CPC you end up with an equation with (R2 + RN) / 4 = R1 where R1 is the line conductors resistance, R2 is the CPC resistance and RN is the resistance of the neutral wire.
My question, Is this method below also an acceptable way of doing it (if the...
Hi guys,
For my current dissertation project at The University of Strathclyde, I am attempting to build an Excel model which calculates PV output for given direct and diffuse solar radiation levels. I have attached below the calculation steps (within figure and as attachment) that I was taught...
Trainees, I realise this will probably be a little over what you will have covered (or in fact will cover) in college. I'm hoping that it may open up a new route of thinking how to plan bigger installs.
Mentors feel free to have a bash. :)
Here's the scenario. (It's from a real job I...
Hello everyone please can someone calculate the current for a three phase machine at 28kw unity pf I already I have seemed to forgot how to use the calculator cheers in advance 27kw three phase
Hi all,
Does anyone know where I can find utilisation factors (UF) to use in lighting calculations. The room in question is under a mezz floor in a church hall.
Regards
Dave
Hi Guys,
Does anyone know of a half decent cable calc programme? I don't mind paying for one that's good and easy to use but some of the ones ive googled seem very expensive to me.
I seem not to have access to the professional forums so I post this here:
I understand ohm's law and to get a current you use Volts/Resistance (V/R); so if it's Perspective Fault Current (PFC), it's V/R or Volts/Ze; and we divided by 1000 to convert to kA. Yes?
Is there a difference when...
Dear Forum Members,
I am hoping you maybe able to provide some cable sizing help. We have a 450KVa generator which has a 400amp Main Switch going to a Dorman Switchgear. Only around 50% of the generator power is currently being used. We had a second generator (170Kva) generator which has...
Hello, I would like to know the approach and calculation how if I are to design 10MW of solar grid tie solar pv system.
Lets say that each panel have the specification as follows..
Power 250W
V- 40v
I- 10A
Inverter efficiency 90%
Grid power output req. 10MW.
Therefore panel output req...
Trying to do a cable calculation to determine the most suitable cable to be used. But l am unsure what to do with the figures in the 17th edition because after 16mm cable onwards there are 3 columns under volt dropr, x, and z. Can anybody show me the calculation which l need to do to determine...
hi all,
dont know if in correct section ofn forum
but here we goes
calculate the diameter of an aluminium busbar which is 24m long and whose resistance is 0.00139
formula a= pl/r and then convert the csa area into a diameter which i dont know how to do.
a = 2.84*10-8*24/0.00139 =4.9
I f im...
been to look at a job with a long main supply approx 60m long underground 25mm 3core SWA running off a 100amp fused isolator.
meter position is at drive entrance and house is approx 60meters away.
not done a voltdrop calc for ages so can someone correct me if i,m wrong.
this is a new build...
When doing the adiabatic calculation for cpc on a circuit greater than 32 amps, do you specify 0.4 or 5 seconds on the trip time?
So my situation would be 40A MCB no RCD 230V and Zs of 0.33 ohms
Kind regards,
Chris
Hi.
Question regarding maximum demand calculation.
I have a customer which wants to have a second kitchen fitted in the house. Is this at all possible?
There are two consumer units in the house.
One which has following circuits:
oven 40A
hob 32A
ring basement 32A
ring gtound floor 32A
ring 1st...
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