Recent content by buns

more of a tingle but a painful one.

I am getting a shock of the screws and earth of one wall socket (and anything metal I plug into it). All other sockets are fine and the only thing I can find wrong is the backbox earth wire to the earth terminal is missing. All other wires are present and correct. Any ideas anyone please?

Interesting, as you worked in the industry you would probably know more than me, so why do they have normally open contacts for use in stop buttons and normally open connections on the UPS. This also doesn't change the fact that the system is critical and as someone advised me above there is...

You'll find thats how all UPS are switched off. The idea being that if things fail (like normally closed contacts opening) then the UPS will carry on. You can set the UPS to switch off using a normally closed contact but then a fault will switch the equipment off. Its a question of how...

The stop button has 2 contacts in it 1. A normally open contact which connects to the UPS and switches it off completely when closed. 2. A normally closed contact which connects to the coil and energises the coil until opened. So if you hit the button both things happen while if the...

As I understand it (and I am not an electrician) the power is supplied through the contactor which is basically a switch, open and closed, off and on. The switch is controlled by a coil, if the coil is energised by applying power to a1/a1 then the switch closes and is 'on'. If you hit the stop...

me again, this has got popular. Basically we have a stop button because our rules say we have to have one also we tend to work on equipment with the power still on. The system I have has UPS anyway so if the coil failed the system would not shut down. Also also the areas we have the...

Just thought I'd wind my contribution - My server rack has a UPS, so we use a regular wall socket to power the rack when doing stuff so failure no real problem. I presume the use of a start button to prevent restart is more for machinery and tools rather than servers? The main thing is am...

understood, ta very much

supply to a server rack is the application. What I've got is a 16A supply through a contactor with the stop button stopping the contactor. The question posed to me was 'why not just put the supply through the stop button?' hence the above question. Your reply gives me another question though...

Is it true that the red stop buttons are limited to 13A and hence you need a contactor for higher current supplies?

thanks

Related to a comment below - given that an RCD/MCB will trip if you accidentally connect neutral to earth in a wall socket even with the MCB switched off(I discovered), is there any danger involved with only the live being isolated or is it just annoying?

thanks, had a feeling it would be

My shower is on the same 32A MCB as the cooker circuit (it was like that when I got here). While this isn't normal is it a problem regulations wise?