Emergency stops for LAB sockets

infinity · Nov 21, 2013

I have been tasked with installing emergency stop buttons at the doorways to a few labs, so in an emergency they can hit the stop button and it will kill the power to all the sockets in the room.

Now the problem is they are all rings with the DB's some distance away. Had they been radials t would be easy, simply break the circuit as it comes in and wire through the EMG Stop, job done, has anyone had a scenario like this and overcome it?

Would the only way be by mounting something at the DB Like a 4 pole relay, wire the ring from the MCB straight into it, and control that by an EMG Stop button sited in the circuits room, wired from the DB where the sockets are?

Or possibly catch the ring as it enters the room and mount the relay there if the legs close together, as some rooms are Dado trunking on walls.

Any advice/ help?

Hawkmoon · Nov 22, 2013

If I were faced with this (as described) I would:

1) Install submain DB to each lab incorporating contactor etc on din rail.
2) Get above ceilings and rewire/reroute all cabling as necessary to separate the labs/offices accordingly.
3) End result - each lab with own ring fed from new sub DB
4) E-Stop with keyswitch wherever.

A lot of work/cost etc but I don't see an alternative - just get stuck in!

tazz · Nov 22, 2013

good constructive input

Engineer54 · Nov 22, 2013

Hawkmoon said:
If I were faced with this (as described) I would:

1) Install submain DB to each lab incorporating contactor etc on din rail.
2) Get above ceilings and rewire/reroute all cabling as necessary to separate the labs/offices accordingly.
3) End result - each lab with own ring fed from new sub DB
4) E-Stop with keyswitch wherever.

A lot of work/cost etc but I don't see an alternative - just get stuck in!

Very similar to the requirements within our Medical Labs Building, except ours are a bit more involved, many being monitored by safety isolation supply units (similar to that found in many school lab classrooms), and a hazardous gas detection alarm system....

Hawkmoon · Nov 22, 2013

Engineer54 said:
Very similar to the requirements within our Medical Labs Building, except ours are a bit more involved, many being monitored by safety isolation supply units (similar to that found in many school lab classrooms), and a hazardous gas detection alarm system....

Not worked on that kind of setup - sounds interesting.

Strangest emergency stop install I've come across was in a number of MOD establishments where the stop button, when pushed, shorted neutral & earth on an RCD protected server installation (N+E picked up at nearest socket then wired to n/o on stop). I wasn't testing the install so thankfully did not have to code it lol.