Latest News

 

Caledonian's MD Bernard Patrick sets the record straight in H&V News article

Wittily entitled 'As a matter of fat' by News editor Simon Duddy and with by-line 'Ensuring safety of ventilation systems in commercial kitchens can provide considerable challenges' Bernard has given an in depth analysis of the requirements of proving air flow in BS6173 gas interlock applications.  Particular attention has be paid to the use of indirect current sensing methods as many such installations fail to meet current requirements.

The article was conceived and written to coincide with the launch of the ECS10 Current Sensor.

For the full article click here

CCTL are pleased to announce that the ECS10 motor current monitor is now available for use with their range of commercial kitchen gas interlock controls.  The ECS10 is a fully indicating instrument that allows an output relay to operate at precisely determined current levels.

Managing Director, Bernard Patrick continues:
“Whilst the HSE accepts the use of current monitoring as a means of proving the safe operation of fans, it is important to realise that this type of sensor can only be safely used if safe ‘pull-in’ and ‘drop-out’ current levels are precisely determined and then set.  All too often installations are encountered that are unsafe because an inappropriate ‘works every-time’ current level is used.

For safety critical applications such as BS6173, the ECS10 allows the ‘pull-in’ and ‘drop-out’ current levels to be set both quickly and easily via the front panel.  The clear LCD screen continuously displays the average motor current during operation. When the ECS10 is used in conjunction with the certified EMX50 gas interlock control, the system will perform to internationally accepted fail safe levels.

Lastly, a word of caution, in that the relationship between fan motor current consumption and the workload of the fan is dependent on several factors. If a fan motor has been greatly oversized it may well be impossible to use its’ current consumption as a safe indicator of performance.”
 

The Caledonian ECS10
- the only 'intelligent'
Electronic Current Sensor
 currently available.

The following letter written by Caledonian's Managing Director appeared in the letters section of a recent edition of H&V News.  The letter was written following the recent court  judgement in a case involving the death of a young girl due to CO poisoning.

Low standards are really appalling

Sir
Unfortunately the heartrending loss of Elizabeth Giauque to CO poisoning should not come as a surprise.  Likewise that ignorance and incompetence were to blame.
As an engineer who has specialised in the design of combustion safety controls for over 40 years I’m appalled at the low standards that now exist in the gas industry, particularly since the dismemberment of the British Gas Corporation (BGC).
As in all industries, there is good and bad, but surely the basic structure that now exists does not compare to that of the days of BGC? This is particularly true when one moves away from residential installations into the commercial and industrial arenas.
For example, although the bypassing of safety controls used in commercial kitchen ventilation is now proscribed by the HSE,  I am astonished that this most stupid and criminal act was ever condoned in the first place.
It may not be permitted now, but some CORGI technicians are still passing new jobs, as well as thousands of existing installations, that are capable of  running without a safety control as soon as the back is turned. Many of these so called safety controls are produced by manufacturers without the benefit of independent certification, CE marking, ISO registration or any attempt at fail safety.
The connection between inadequate ventilation and the excess air requirements of gas burning appliances is often overlooked and rarely fully understood. Oxygen depletion and CO generation due to inadequate ventilation is not uncommon.
Although deaths are rare, the symptoms of headache, tiredness and nausea are, sadly, still dismissed in some kitchens as ‘occupational hazards’.

Bernard Patrick, Managing Director, Caledonian Control Technology

CORGI Gas Installer magazine asks "Is it worth the risk?"

The following letter written by Caledonian's Managing Director appeared in the 'Dear Editor' section of a recent edition of the CORGI Gas Installer - essential reading for CORGI registered gas installers.  The telling title was chosen by the editor, Eoin McManus:

Is it worth the risk?

We have found in our discussions with equipment manufacturers and installers of gas appliances in commercial catering establishments some confusion as to the requirements of BS6173 with respect to their products and installations. This must be particularly worrying for CORGI registered installers who shoulder the responsibility for ensuring and certifying compliance. 
The Health and Safety Executive in their guidance leaflet no. 23 entitled Gas safety in catering and hospitality^* offer a clear interpretation of BS6173’s requirements.  They also indicate that a CORGI installer should be used as the ‘competent person’ as required by law.
Surely, as with the humble gas valve, a CORGI gas installer would not use a device which hadn’t been certified to comply with the relevant standards? It’s more than their job’s worth!  It would appear though, that when it comes to the installation of gas interlock controls, they are prepared to use non certified equipment. Not only do they seem prepared to take this huge personal risk, but we would also dare to add that many such controls would not get, if tested, the necessary certification
.
Bernard Patrick, Managing Director, Caledonian Control Technology Ltd.

^*Copies of HSE leaflet no. 23 ‘Gas safety in catering and hospitality’ can be found on the HSE website at the following address: http://www.hse.gov.uk/pubns/cais23.pdf

The EMX50 gas interlock control - certified by Advantica to comply with BS6173

Whilst Caledonian Control Technology Limited advocates the use of true volumetric air proving when at all possible utilising differential pressure sensors or anemometer technology, we have conducted a series of experiments to determine whether an indirect method, and more specifically using current sensing, can be safely employed.

The following three basic aspects have to be considered if an indirect method is to be deemed safe:

• Can a safe start test be made?  i.e. is the sensor working
• Can a rising set point be set?
• Can a falling set point be set?

We found in our tests that all of these criteria could be met and that an indirect current sensing methodology could be used safely in situations where direct methods are inappropriate or even impossible.

The chart to the right, which plots Air Flow against Motor Current drawn in Amps, clearly shows that there was, for our test ventilation system, a specific range of current drawn when the system was working correctly.

We named this the ‘Effective Range’

When employing this test in the ‘real world’ the effective range has to be determined for each installation so that the controller and sensor can be calibrated.

Having done this correctly, we found that using the indirect current sensing method is as reliable and safe as the more traditional direct methods.

Request the full report: