Hi All,
Looking for some advice, I have been issued a drawing of a large warehouse lighting layout. the drawing shows 72 high bay lights including 29 self contained emergencies. The specification from the manufacture details that the Protective device must be a C16 and a maximum of 3 lights...
I have brought this to the clients attention. Future works could be replacing the consumer unit. As in a poor condition. Mismatched Mcbs and circuit being doubled up in 1 mcb
Experts opinion required.
Ask to add some addition fittings to a lighting circuit within a shop. Opened up the consumer unit to access the circuit. And noticed the tails from the service head to the meter and from the meter to the consumer unit look very suspicious. I have experience with...
ok,
a little confused now. sorry for throwing in the volt drop calculate that hasn't helped to flow.
I am trying the establish the minimum circuit protective conductor.
i have a 50mm² line conductor with a 25mm² CPC protected by a bs88 125A. i have determined the fault current at the...
Sorry guys went off on a bit of a tangent asking about the volt drop. But thank you for your responses.
Sorry Strima, we must have posted those replies at the same time.
The reason I was asking about the fault current was in all the books you calculate the fault current at the extremity of the...
Thank you Richard,
As you are an expert i have another question for you regarding volt drop.
I came across a volt drop calculation whilst reading one of the many books i now own. This was a lighting circuits and the equation was
Volt drop = mV/A/m × (Ib ∕ 2) × Length
with an evenly...
This forum has some awesome members. The speed that my questions have been answered is amazing.
Following on from the cpc sizing when the ocpd is a mcb. I now have a situation where I have a 16A fuse to bs88 with a fault current of over 700A all the manufactures chart only go down to 0.01 so...
Thank you,
That makes everything crystal clearer.
still have a problem with the logarithmic scale for schneider.
I have downloaded the brochure.
but there are 4 charts for the IC60H 2 on page 335 and 2 on page 338. i have assumed i am to use the one with the A2s but what are the others...
Ok, so been reading all week and still can’t get my head around this.
can someone please confirm my thinking on this.
Sizing of CPC with an MCB where the disconnection time is less than 0.1 sec.
When the disconnection times for an MCB is less than 0.1 sec (instantaneous) you can no longer use...
Sorry another New Question,
I am trying to work out if the CPC is adequate but get some conflicting information.
I was always taught that if the fault current causes instantaneous operation then use 0.1 in the adiabatic equation.
However, I’ve been reading up and regulation 434.5.2 states...
Thank you for all your help Richard.
The reason i have halved the 0.387Ω is because the circuit conductor is only 0.5m long.
A²s i think is measurement of let through energy.
Dan
Richard thanks for your response, i have revised the calculation and included the full calc
this is at the origin of the installation, and the PSCC in 5KA, as the devices are 88 at 80KA and 60898 at 6KA do i need to determine short circuti current?
Main Switch to CCU
the design current of...
Hi everyone,
Finished my exam last Thursday and it has taken till now to get over it. how is it only 3 hours. I think it all went well, but didn't managed to complete hopefully scored enough on the questions i did answer thou.
New question for you experts, still on the same topic short...
Thanks for all your replies. Just going back through notes now and its something that we covered but had just forgotten. Got the exam next Thursday. So 5 days left of rereading books and notes. Thanks for the advice on the examiners reports. Got the last six. The same things seem to come up. Not...
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