* Posts by c c c p

2 publicly visible posts • joined 11 May 2018

Why is the printer spouting nonsense... and who on earth tried to wire this plug?

c c c p

Re: The user replied: "The same electrician who changed that plug rewired my house last week!"

The device you describe in your post is an RCD - Residual Current Detector. This identifies the amount of current going "missing" from the circuit (the live and the neutral) and when this exceeds a set amount it will interrupt the supply. (typical values for residual current are 10mA, 30mA and 100mA for large equipment)

A GFI type device relies on the current flowing through the ground circuit through it to detect the issue and interrupt the circuit. The drawback with these is that if the current flows to ground through an alternate path (eg. a person), the GFI will not detect this and interrupt the circuit.

Fixing a printer ended with a dozen fire engines in the car park

c c c p

Flaming bacon sandwiches

A few years back I worked in a largish lab/ office environment with about 12 other engineers. We all enjoyed our food and had taken to ordering delicious bacon / sausage etc sandwiches to be delivered on Friday mornings. One Friday, the usual vendor wasn't delivering and so an alternative was used. Unbeknown to us this vendor wrapped their sandwiches in foil placed inside the brown paper bag. Several of my colleagues liked their sandwiches hot rather than warm and the office microwave was used to achieve this.

One of said colleagues place his brown bag into the microwave without inspecting the contents, set the microwave off and walked away. A few tens of seconds later smoke billowed forth from the microwave and yellow/orange flickering glow could be seen inside. Cue panicked calls of "turn it off", "get it outside" followed by several of our number standing on desks and benches to hold wastepaper bins over the smoke detectors in the office lest we trigger a false alarm evacuating all 300 workers from the building. HR would have taken a dim view and probably banned microwaves, kettles and the delivery of bacon sandwiches...

Needless to say we all learned to inspect our sandwiches more closely after that!