Level 3 2365 design project need info on Q3

ajama21 · Jul 27, 2024

Hi guys, hope you are well. I am currently doing a level 3 2365 design project hotel, swimming pool cafe and I therefore need help on what to do on Q3. If anyone can show me a direction on what to do or show an example of how to do it would be much appreciated
Thanks

James · Jul 27, 2024

What is the question?

ajama21 · Jul 27, 2024

James said:
What is the question?

Select with the aid of manufacturers data, a suitable range of circuit protective devices for this contract. your selection should be based on the following:
Prospective short circuit currents
Requirements for additional protection and special locations.
Thanks for the reply.

westward10 · Jul 27, 2024

That seems a straight forward design question, what are you having difficulty with? What PSSC have you been given at source?

ajama21 · Jul 27, 2024

westward10 said:
That seems a straight forward design question, what are you having difficulty with? What PSSC have you been given at source?

hi mate, 3.7KA IPF pool/café

westward10 · Jul 27, 2024

So what does having 3.7 KA at source, assuming the pool/cafe is the source tell you about the rating of the protective devices through the installation?

ajama21 · Jul 27, 2024

westward10 said:
So what does having 3.7 KA at source, assuming the pool/cafe is the source tell you about the rating of the protective devices through the installation?

thats what im confused about. I dont know the rating to use for it or what circuit breakers to use

westward10 · Jul 27, 2024

Circuit breakers have a maximum breaking capacity normally identified on them in amps. This is normally seen in a box on the device such as 6000, this means 6000A or 6KA. To install a 6 KA device in a distribution board where the PFC is 9KA could result in a damaged device or worse if a fault of such magnitude occurs so the rating of your device must be higher than the PFC at the point it is installed.
Your PFC is 3.7KA or 3700A so your devices must be rated above this. PFC is highest at source and reducing through the installation due to circuit impedances bringing it down.

ajama21 · Jul 28, 2024

westward10 said:
Circuit breakers have a maximum breaking capacity normally identified on them in amps. This is normally seen in a box on the device such as 6000, this means 6000A or 6KA. To install a 6 KA device in a distribution board where the PFC is 9KA could result in a damaged device or worse if a fault of such magnitude occurs so the rating of your device must be higher than the PFC at the point it is installed.
Your PFC is 3.7KA or 3700A so your devices must be rated above this. PFC is highest at source and reducing through the installation due to circuit impedances bringing it down.

Thanks for this info. What type of devices would be beneficial in this case sauna, kitchen, fridges etc..?

westward10 · Jul 28, 2024

You need to do some circuit design to establish the current rating of each protective device then decide what type you need and whether RCD protection is required.

ajama21 · Jul 28, 2024

westward10 said:
You need to do some circuit design to establish the current rating of each protective device then decide what type you need and whether RCD protection is required.

Ive already done the circuit designs. Ive looked into circuit protective device of 61009-1s, 60898s, do i select each of those types for sauna, fridges, pool etc.. take data of them from the manufacturers website and add them to the assignment?

westward10 · Jul 28, 2024

Yes add as much info as possible but not for every one. If you have a board with 36 devices just show what you have selected in terms of mcbs and rcbos. For example if you have twenty 32A type C devices just show one.

ajama21 · Jul 28, 2024

westward10 said:
Yes add as much info as possible but not for every one. If you have a board with 36 devices just show what you have selected in terms of mcbs and rcbos. For example if you have twenty 32A type C devices just show one.

ajama21 · Jul 28, 2024

I get it now. Thanks for the guidance and with this useful info

.

ajama21 · Jul 29, 2024

westward10 said:
Yes add as much info as possible but not for every one. If you have a board with 36 devices just show what you have selected in terms of mcbs and rcbos. For example if you have twenty 32A type C devices just show one.

hi mate sorry for bragging this. i was gonna ask one more thing.in the question it also mentions requirements for additional protection and special locations. What would I have to do for this?

westward10 · Jul 29, 2024

Have you looked up additional protection?

ajama21 · Jul 29, 2024

westward10 said:
Have you looked up additional protection?

Additional protection for socket outlets

Keith Willcock, Product Manager for Siemens Alpha Circuit Protection Products, reviews the implications for designers and installers of electrical installations from the latest requirements for additi

professional-electrician.com

this came up but still don't know what to do .

westward10 · Jul 29, 2024

Do you have BS7671?
Additional protection is explained in there along with special locations and their requirements.

ajama21 · Jul 29, 2024

westward10 said:
Do you have BS7671?
Additional protection is explained in there along with special locations and

Yes I found it. Would I have to take info from bs7671 or take photos of the page selected and apply it to the assignment?

westward10 · Jul 29, 2024

Just quote the Regulation and why you are applying it.

ajama21 · Jul 30, 2024

westward10 said:
Just quote the Regulation and why you are applying it.

thanks for the help truly. I got one more question for Q4, on the table that is shown on the 7nth row (length in meters). for that do i measure the length of the cable from the distribution board to another point of the socket outlet for example in a hotel bedroom ? if you can clarify on what i should do then that would be much appreciated. I know I'm asking

a lot but this would be a big help

westward10 · Jul 30, 2024

Length of circuit you need to measure using the scale on the plan including drops or rises to accessories. If the circuit has five points on a radial the distance is to the furthest. For volt drop if the circuit does not originate from the source you must include the volt drop of the sub main, either way make it clear how you came to the figure.

ajama21 · Aug 1, 2024

westward10 said:
Length of circuit you need to measure using the scale on the plan including drops or rises to accessories. If the circuit has five points on a radial the distance is to the furthest. For volt drop if the circuit does not originate from the source you must include the volt drop of the sub main, either way make it clear how you came to the figure.

westward10 said:
Length of circuit you need to measure using the scale on the plan including drops or rises to accessories. If the circuit has five points on a radial the distance is to the furthest. For volt drop if the circuit does not originate from the source you must include the volt drop of the sub main, either way make it clear how you came to

westward10 said:
Length of circuit you need to measure using the scale on the plan including drops or rises to accessories. If the circuit has five points on a radial the distance is to the furthest. For volt drop if the circuit does not originate from the source you must include the volt drop of the sub main, either way make it clear how you came to the figure.

The one I labelled are the led lights for the swimming pool do I measure the lengths of all of them up to the db for the swimming pools lights which are coloured yellow that is going to the switch and till the db do I measure all of them. Can you show me what I'm doing wrong in terms of the measurements

westward10 · Aug 1, 2024

You neasure from the DB to the furthest point.

ajama21 · Aug 1, 2024

westward10 said:
You neasure from the DB to the furthest point.

thanks. for actual ZS is the formula Ze+(R1+R2) ze+0.8 zdb+0.11 do you take the ze value to add whatever i get from R1+R2 instead of using the zdb value