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thescruff · Moderator Joined: 03 May 2003 Posts: 4751 Location: Bath

Vince below is a pm sent too me Shocked

Hi,
First of all may I say that I appreciate any time spent on this and thank you in advance.
Its rather confirming my suspicions rather than any in-depth technical question.
It’s a bar that I installed some touch screen tills. These are computers with 17” touch panels. From day one we have problems with the tills and receipt printers. The printers would simply stop and the computers would freeze for a while. I have tried to eliminate computer or network as the fault and am satisfied that the fault lies elsewhere.
One of the three tills works fine and has not experienced any problems. I swapped the position of these tills and the till that didn’t experience problems had developed problems. It was true to say that the till that previously experienced problems now does not.

The bar is an “L” shape and two tills are at one end (the troubled end) and the third is at the other (no problem end).
I’ve discovered that the bar is powered by two ring mains on two different MCB boards. Behind the bar is a commercial kitchen able to produce 100 covers an hour, albeit a very compact kitchen.
I’ve discovered that one of the ring main to the bar (the troubled end) is fed from the same boards as the kitchen. The breaker board has another board of equal size joined from it using what looks like a 30 amp cable (white and flat about 3.5mm)……Only one of the boards has a master trip of 100 amp the other board fed from it has a whole where I would have expected to see the master trip, you could easily touch the brass connectors inside the board. I do have photos if this helps? The boards are situated next to a dish washer in fact only inches from the dish washer and the operator. The plastic covers have both been smashed and blue tack holds the covers in place.

My question is would the fact that the bar is run from the same boards as the kitchen (commercial deep fat fryers, dish washers, microwaves etc) will this create problems to computer equipment?
The kitchen is fed by three faze but all appliances are single faze I understand.
I have totalled up the appliances on the bar ring main and they come to 12 amp on each but most of these are bar fridges and beer flash chillers for cold beer.

Should I ask for a clean mains and how would this be done?

Thanks for your help

Steff
PS
Do they have a duty to sort out the potential of electrical shocks because of the height and placement of the boards?

vince knight · Posted: Sat Jan 14, 2006 9:32 pm Post subject:

Firstly, as the paying public use the premises, they have to have the electrical system tested and inspected yearly. From what you have discribed it is not in a safe condition.
As to your problem.
1. The various heating elements, motors, transformers lighting controllers all place noise and spikes onto the mains supply.
2. The distance your bar sockets are from the origin of the supply might be presenting you with a volt-drop so the voltage at the sockets is more than 10% less than 240v.

The first thing I would do is check the voltage at the problem sockets and monitor it for 10mins or so while the kitchen is in full swing.
Next I would fit a surge and spike protecting socket to all tills.
If that fails to improve the situation, then a clean supply should be installed to power the tills. This will involve running the supply throu a voltage stabilzer.
Have the sockets got a good earth?

Hope this has been of some help.
Let us know how you get on or if you get any problems please ask.

Vince

SoItBeS · Guest

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