Just started Level 3 C&G and we're doing cable sizing calcs. Using a previous years exam question.
We ran through a few examples of radial circuits, all well and good. Following the following proceedure:
Work out total load on circuit from plan.
Work out design current. Ib.
Ib<In<It
Find...
Hi all,
I am trying to calculate a SWA 4 core that will be protected by a 250 amp switched fuse isolator. It is going to supply a 3 phase electric boiler that pulls 209 amps each phase at most. I'm filling in the parameters to an online cable calculator ,when asked for the voltage i've put 400...
Hi all,
Hope you're keeping well
I'm currently wiring a small commercial premises. 3 phas incoming supply, 16sq cables
As it is in an urban area with a busy pedestrian street on both sides of the building I had to drive the earth rod just inside the door of the premises. However it is located...
Happy New Year all.
Quick question regarding cable sizing. I have a 25m run from DB to car charging unit. The 25m run will mean approx 8m is run in the attic, 6m is run clipped direct down and across a wall and the remaining 10-11m will be buried underground in a 2 inch duct to the car charging...
Hi, I recently discovered at my brother in laws that he has a circuit which feeds a outbuilding, but we also discovered that it’s attached to a small part of the downstairs sockets towards the rear of the house! The concern is this outbuilding then goes on to feed another small shed.. is this...
Morning All,
Think I'm having a brain fart but I have a 70mm2 4 core SWA with a separate 35mm2 CPC.
Earthing is TNS with main bonding requirements being 25mm2.
Using table 54.7 - CPC is half of line conductor so 35mm2.
Am I correct in thinking the 35mm2 conductor is adequate for both CPC and...
Greetings,
I'm a EE and have installed many electrical systems but am now dealing with my first large 3PH install on our property. I'm not formally trained in this area but very familiar as a EE. Anyway, can someone help me with proper neutral wire sizing?
I've done a bunch of research...
I’ve got a job to quote for turning 1 big flat into 2 smaller flats. The DNO are looking at installing new meters in the communal area. I need to take an SWA from each meter to the individual flats which one is around 15m and other is around 30m away.
Would a 25mm 3 core swa be the best for...
Hi, just want to check something. I am on a facility which has a 4 core 70mm non armoured feed from the transformer, coming into the DB at the other end it is now a 4 core 25mm non armoured cable (obviously it has a joint somewhere) and the earth conductor is from an unknown source, but both of...
I am an enthusiastic retired engineer rebuilding a barn in France from scratch and am having problems sizing my incoming electrical cables. I have had answers from 4mm to 50mm cross section from various pages on the internet so you can understand I am a bit confused.
There are two main cables...
So, I already have solar (an older FITS installation) and it's been particularly successful so I want to extend this.
I'd like to do two things at this point. 1) Add more panels in a couple of locations. 2) Add battery storage to provide some backup (power regularly drops for us) but mainly to...
Hi, I am finishing up my design drawing for submission. I am working out all my circuit calculations and am a bit confused about what size I should use for my circuits which are supplies for my additional Distribution Boards ( Hotel, Pool, Summerhouse etc ). My hotel DB however even when...
Am I over thinking this, Pitch socket for caravan TT system 16 amp MCB, Rcd protection 30ma, supply 2.5 flex to DB in caravan also RCD protected.
What’s the requirements for the MBPC for the caravan,minimum requirement 6mm to the DB MET
With the supply cable 2.5mm flex this is not achievable...
Hi folks,
I have been researching the NEC and forums on the Internet in preparation for adding an RV subpanel electrical hookup. I could use a sanity check to make sure that I'm buying the right type of cable(s), and that I'm adhering to code as best I can.
I have 200a service to my main...
Hi all.
Could I ask some advice please regarding SWA banjo fly lead sizing.
Can anyone explain what sizing or how you size the required earth size when:
A) The armourings are not used as cpc
B) When armourings are used as CPC?
I’m still learning and can’t find anything explain I guess this...
Hi all
I would like to know what should be the rating of Air Circuit Breaker to select for a Genset based on the following data:
2000k VA
PF 0.8
1600k W load connected to the Genset via dedicated busduct.
Supply: 415 V
I have an idean in mind (whether right or wrong) but I would like you to...
Running a new circuit to an AC unit, making sure I'm on the right track. The attached chart has the information for this unit which is on column 4.
Maximum overcurrent protection: 30 amps
Minimum circuit ampacity: 19amps
240 volts
It will be running across a rooftop in a pretty hot location...
Running some cables and fitting some back boxes to save some money in preparation for an electrician to do a 1st fix. Just wondering if there is a simple table available to show what size cable(s) will fit into oval conduit?
Specifically 2 x 6mm2 T+E cables (induction hob and oven) and 2 x 4mm2...
Hi all.
I've been out to look at a mates new (to him) air compressor. It's 15kw 3phase star-delta run. He's off grid and currently has a 20kVa Genny running his farm.
This is obviously undersized for starting the compressor, when tried the Genny bogs down and contactors start chattering. He's...
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