Electrical safety - power adapters and extension leads

[hockings]

Hi all!
I'm just starting off on my Christmas lighting adventure (my handful of strings and one custom creation look awfully woeful!) and am trying to make sure I understand everything from the ground up. I'm just starting to look into low voltage setups (for safety reasons) but thought I'd put a couple of questions to the masses that have been bothering me, and I can't get a consistent answer from google. I have a bit of electrical knowledge (I understand the basic theories) but I'm happy for it to be simplified!

1) Why is daisy chaining multiple powerboards/leads dangerous? I would've thought that technically this would be fine as long as you're not exceeding the maximum rating for the circuit they're all attached to through the combined power draw of all attached devices?

2) Why is coiling extension leads dangerous? I thought it would have something to do with creating a magnetic field, but couldn't work out from google posts where people were talking about it why that would be actually dangerous. The consensus seemed to be heat generation leading to melting the wire sheaths, but I'd prefer to hear the thoughts of people who are working with electrical equipment rather than random internet posters.

Thanks in advance!

 

[fasteddy]

Hi all!
I'm just starting off on my Christmas lighting adventure (my handful of strings and one custom creation look awfully woeful!) and am trying to make sure I understand everything from the ground up. I'm just starting to look into low voltage setups (for safety reasons) but thought I'd put a couple of questions to the masses that have been bothering me, and I can't get a consistent answer from google. I have a bit of electrical knowledge (I understand the basic theories) but I'm happy for it to be simplified!

Welcome to ACL, you are making the right choice using low voltage

1) Why is daisy chaining multiple powerboards/leads dangerous? I would've thought that technically this would be fine as long as you're not exceeding the maximum rating for the circuit they're all attached to through the combined power draw of all attached devices?

The issue is more around overloading them and is more a general precuation

2) Why is coiling extension leads dangerous? I thought it would have something to do with creating a magnetic field, but couldn't work out from google posts where people were talking about it why that would be actually dangerous. The consensus seemed to be heat generation leading to melting the wire sheaths, but I'd prefer to hear the thoughts of people who are working with electrical equipment rather than random internet posters.

By coiling up a cable you are in effect creating a magnetic coil, the more turns the more the magnetic feild that is created. This then heats up the cables. Look at it as having a magnetic coil for a solenoid, if you remove the coil from the solenoid and leave power on, the coil will eventually burn out due the magnetic field.

Thanks in advance!