WHY DOES A PLUG GET HOT - WHY WILL A 13 AMP FUSE NOT FUSE EVEN AT 20 AMPS - USING THE FUSING TABLES
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- čas přidán 28. 06. 2024
- Very recently, I was asked the following question about plug top fuses …
If it says 13 amps on the fuse … then why does it not fuse at 13 amps? Which is true.
So in this video from LearnElectrics we will look at this, explain the reasons for it and answer some other questions like -
Why does a 13 amp plug, or plug top as we call them, overheat?
And a popular question, can a 13 amp fuse REALLY carry 20 amps
And we will also look at the fusing characteristics of a BS1362 fuse and explain how the fusing tables work and how we can quickly and easily interpret the information that they hold. Hopefully, things will be a lot clearer afterwards and a little more knowledge will have been stored in your mental toolbox.
If we can understand the fusing curves of a BS1362 plug top fuse, as shown in this particular video, then we will also understand how the fusing tables work for other fuse types.
Each fuse type will have its own unique requirements, how much current, how much time etc. as defined by the relevant design standards for that fuse. They are all different but have many similarities in how they are laid out and in how to interpret them.
This is video number 248 and to view all our videos type in LearnElectrics all one word into the CZcams search bar.
Visit our CZcams channel where we have many more videos on a wide range of electrical topics.
I'm just about to finish Level 3 after 2 years of study and here I am learning valuable information about a plug top from CZcams. Thank you.
Mate this is so useful. I will never look at a plug the same again. Just brilliant. Thankyou. Please keep the videos going.
Thanks, will do. Lots more to come and glad you liked the video. Dave.
Thank you again - Very clear presentation - Every domestic user should know this
Can't get better than this. Thanks for sharing
Well as usual you are amazing. They do not teach this stuff, all your videos are so educational..
Thank you!
Thanks for the great feedback, appreciated. Dave.
Yet another of your brilliant videos David
Thank you! Is the plug in the end of the video miswired on purpose?
Yes. It could be to test the viewers.
may you add another vedio about how to find a .short circuit or wire, in a house
Great little video Dave-
Glad you enjoyed it and thanks for the comments. Dave.
Great video as ever Dave. Why do manufacturers and British Standards design these fusing factors into their overload devices? Why can’t a fuse with an “In” of 13A operate at 13A of current? Or an MCB with an “In” of 32A operate at 32A?
Wow! This video is very informative and the best video tutorial on the topic for me so far. I really appreciate it. Thanks for sharing it with us Dave
An other good video with need to know info. But is there other sizes of fuses available for smaller appliances. Thanks for sharing.
Yes there are other sizes. The trend now is to install either 3 amp or 13 amp, as required, and 5 amp for computers.
I'm here again thanks for sharing this with us
It's amazing how many experienced sparks don't even understand the concept of Fusing factors and tables. For example, how many times do we see immersion heaters fed from a 13A FCU instead of a 20A DP switch? Thanks for the usual, clear way of sharing your knowledge 👏
If the cable from the switch to the immersion is suitably rated, then why is it a problem? Immersion elements are 3000w drawing 12.5 A for about an hour per full tank reheat. 1.5mm heat resistant flex has a rating of 16A, I would use 2.5mm which is 24A. The whole circuit should be on a 16A MCB/RCBO. I would argue either method of isolation is satisfactory, but every day is a school day?
@@MikeSmith-tx2lp interesting to see you choose 2.5mm over 1.5mm even though 1.5mm is rated at 16A and well above the 12.5-13A the element can draw. I agree with your choice and for me, it is because of the time the cable and switch will be drawing that current for 2 hours or thereabouts for an average 117L tank, rather than the hour you suggest, and doing that cycling regularly will and does eventually deteriorate the plastic of the FCU. Also, as you point out the regs stipulate it should be on its own circuit anyway, so does it need a 13A BS1362 after your OCPD in the board? I don't think so. And yes, every day is a school day for me as well.
@@olly7673 Nice discussion, how it should be. Made me think a bit more and I’m now going to replace a couple that I have put on FCUs with the 20A DP switch. Why else would they make one !? I have seen the heat damage on older installations, it’s real. I prefer the 2.5mm flex just for the safety margin but it’s probably overkill as the load won’t draw more than 13A and the 16A mcb will instantly trip on a live fault and the RCD/RCBO will catch the other more likely faults. Same argument for purpose built immersion timers, they need to be rated for the duty cycle. Now shall we discuss the cooker diversity chestnut ?👍😎
Another amazing video well done, could you please have a look at plug picture ?
The plug picture near the end is next to the paragraph that says always check plugs when doing PAT testing. Well done for spotting this. Dave.
The 3 pin plug at 14 min has the blue wire connected to the fuse?
Yes it does. It's next to the paragraph about checking plugs when PAT testing. Thanks for watching, appreciated, Dave.
Well done spotting the deliberate mistake