I think I share your lack of confidence, and even wonder  if it is the right solution to a problem that may not even exist  - after all is there a lot of  expense/damage each year due to frequent fires while cooking in this accommodation ?  If not is it just adding another thing to go wrong, with contacts that carry the full current and almost never operate - that will slowly oxidise and go high impedance....

  Can the reset switches be easily operated or the alarm disabled as required ? If not anyone doing flambe cooking will be disappointed.

Looking at what happens to any smoke alarms that are more trouble than use, they need to be pretty reliable in operation and solidly constructed. I wonder how well it can learn the 'safe' cooking patterns for a number of people with very different styles of cooking sharing a kitchen, and if this just involves tripping and learning when it was reset and then not tripping at that level again.

Mike.

This is student accommodation.  if anyone is doing flambe cooking, it's probably not intentional.

Fit a hob run back timer that turns the hob off after fifteen minutes, making the person cooking stay in attendance to reset it.

Thank you for your input. I think the right course of action here is to find out more about the clients motives. I have surveyed a number of sites and had no reports of issues with the exisitng setups. As it happens they do have something similar to the following installed in some locations: 

PRE9275 - Prefect Controls - Cleverly Simple Control of Energy

They seem like a much more robust and cost effective option.

Our induction hob has a similar feature built-in (but after several hours) - which is a right pain when it comes to steaming the Christmas pudding. You also have to balance things against the risk of food poisoning etc if food isn't cooked properly.

   - Andy.

The Stoveguard and the hob run back timer are both good ideas and used correctly should work fine.  This scenario sound like it could almost be a C&G 2396 level 4 question. 

How will it operate under normal conditions?

How will it operate under fault conditions?

How will it operate if the end user tries to circumvent it?

How will it operate when end user is under the influence of .........?

This will turn into a very interesting debate

The web site seems decidedly lacking in technical information (not to mention they try to re-direct to a different site that doesn't have its security certificates set up properly

I don't like the idea of the sensor unit being attached to the hood - it's going to get gunged up with grease in no time - and you can't expect it to be kept clean in a student environment. There precious little data about the control unit either - the connectors look like the 16A ones you see on lighting installations - which won't be much cop for a typical UK 32A+ single phase setup. Maybe an additional contactor will be needed, but that rubbishes their low power consumption claims and would make installation much more difficult. I wonder how it interacts with conventional fire alarm systems? - I think such kitchens would often have heat detectors - which would trigger first?. The general idea does appeal - but in my mind there's some outstanding questions about the details of the implementation. Maybe better information would reassure.

   - Andy.

I agree with the point about the existing fire alarm - having something that kills power to the cooker if the existing alarms go off might be  more sensible - it does not even have to wire in to the alarm -  there are things that listen for a fire alarm, and then for example lower roller shutters or release door catches - a variation on that theme might be more use than an independent detector of unknown enthusiasm and state of maintenance. That way it gets tested as the alarms do.

(though we have a fire door using one of those  that closes when folk are washing up with too much  enthusiastic clinking of mugs, so the detection of 'alarm sound' may be a bit keen on some models.)

And maybe it's an influence of my scouting/camping hobby but I often fry things with a bit a of flame in the pan, even indoors., and I'd be quite miffed if the power kept getting cut. And deep in the last century, I have been a student...

Mike.

It seems Norway is leading the way with this type of equipment and there are various products available.

Norway has a building code standard from 1 July 2011 shut-off devices are required in new electric stove installations (Norwegian standard NEK 400:2010 Electrical low voltage installations. Part 400-8-823 residential buildings).

Interesting. I see they do not consider normal fire/smoke alarms sensitive enough.

round here they seem to be too sensitive but hey-ho.

translating from here

"823.421 Protection against fire caused by electrical equipment

823.421.01 Cooker/hob To reduce the risk of fire when using the hob (as an independent unit or as an integrated in a stove) protective measures must be arranged in the fixed installation, which ensure disconnecting the power supply to the hob if danger arises when using the hob for overheating. The protective equipment must be permanently mounted.

GUIDELINE 1 – The protective measure can be arranged, for example, by installing a separate over-temperature monitoring equipment (for example, directly above the cooker/hob) which causes the equipment to be switched off and indicates this with a sound and light signal. Ordinary fire detectors/smoke alarms in the ceiling will not normally work quickly enough.

GUIDELINE 2 – A time switch is not to be considered a device that protects against overheating. The protective equipment must be of class B or class AB in accordance with NEK EN 50615.

GUIDELINE 3 - The purpose of the requirement in section 823.421.01 is to prevent a fire occurring due to use of one cooker/hob. The intention is that the protective measure should be effective in every situation and use hob/stove, and an important element of this lies in the fact that it is not possible either accidentally or in a simple way to disable the measure. The following points show how the intentions of the requirement in 823.421.01 are taken care of that the protective measure: is part of the permanent electrical installation, cannot be taken out of operation without intervention in the electrical installation, actively monitors the temperature progress of what is being cooked on the hob and prevents overheating where possible entail a risk of fire,  disconnects the power to the hob when danger occurs, and indicates disconnection with a sound and light signal, gives, if the sensor has a battery, a signal for a period when the battery needs to be replaced,  if the battery is empty or not installed, switch off the power supply to the stove, and can be manually overridden in an emergency, for example in the event of a sensor failure or similar."

It would be interesting to know  if their kitchen fire accident rate has fallen much since this got added.

Mike