To Isolate or Not to Isolate - Working Dead to Stay Alive


15 January 2016
by Stephen Benton, ​Cool Concerns
Often we hear “I have always done it like this”.  If we are honest with ourselves we have all said it at some time, the more fundamental question we should ask is “have we always been doing it right?”. 

There is a right way and a quick way; sometimes they are the same thing, but more often we think the right way will delay us from getting to the next three jobs. Consider then that the failure to do something correctly, that might only involve 5 minutes more work, could result in weeks off work with an injury or a lifetime dead (that’s a more permanent delay, is it not?). That perceived need to save time is often why accidents happen, coupled with the certainty that all men have “that it will not happen to me”!

Engineers often don’t safely isolate electrical equipment before working. I worked for decades without correctly locking off electrical equipment before undertaking maintenance or repair work. The Health & Safety culture in the refrigeration industry has certainly improved beyond all recognition from those days, but largely from a paper trail perspective.  Engineers still follow less than best practice on a daily basis.
So, what are the reasons / barriers to safe electrical isolation, with the inevitable first on my list:
  1. I have always done it like this;
  2. I don’t have an safe electrical isolation procedure;
  3. I don’t have electrical isolation ‘lock off’ equipment;
  4. I thought I was doing the customer a favour;
  5. I have items 2 and 3 but still make the decision based on 1, 4 and 6;
  6. It’s never happened to me!
So with the majority of us fitting now uneasily into categories 1 and 5 of the above read on.
Incorrect isolation can result in electric shock and / or injuries due to equipment starting up unexpectedly. Both outcomes are potentially fatal at worst and can inflict horrendous or life changing injuries at best. Remember, when you joke with colleagues that you got yet another electric shock “only a little tickle”, this is only emphasising to everyone that there are some basics missing in your competence.

Engineers are not always aware of correct isolation procedures and may not have the appropriate training or equipment. We have developed simple training to meet the needs of one contractor whose engineers had suffered a few accidents which could have been avoided with safe electrical isolation practices. In reality most refrigeration engineers need an introduction to / a reminder of good practice. This is part of a larger culture change needed throughout our industry to ensure that we are all safe in an increasingly pressurised work environment.

​What we covered – back to basics:

  • What to expect when you measure voltage, current, resistance;
  • How to measure, using appropriate tools safely;
  • Working dead (an odd title but directly related to staying alive);
  • Safe electrical isolation;
  • Diagnosing electrical faults – probes, fan motors;
  • Replacing probes and motors so the replacement works reliably – cable joints.
The training includes practical hands on exercises. Each candidate is assessed using RoSPA accredited e-learning and a practical assessment measuring single and three phase power supplies and safely isolating, confirming isolation, locking off and reinstating.

For practical health and safety to triumph we need a culture change at all levels.  The A4 folder of risk assessments we all carry in the vehicle is less important than using the right electrical test and lock off tools and competently isolating and locking off an electrical supply before working on a piece of equipment.

​So ask yourself, do you have the below in your tool bag and do you know how to use and apply it following the procedure?   If you do, great! If you don’t then correct that today, yours or a colleague’s life might depend on it!
  • Equipment Required:
  • Safe Isolation
  • Reinstating the Supply
  • Isolation padlock & key
  • Multiple worker isolation padlock tag
  • Isolation devices to suit different isolators / MCB’s etc
  • Warning notices
  • Voltage tester
  • Voltage proving unit.
  1. Identify the circuit or equipment to be worked on
  2. Check condition of voltage tester and operation against a known voltage supply
  3. Isolate supply and secure isolation – lock off (multi lock off if multiple workers)
  4. Prove circuit dead – use voltage tester and re check against a known voltage supply
  5. Retain keys and post ‘caution’ and ‘danger’ notices
  6. Take precautions against adjacent live circuits / equipment – if any
  7. Issue permit to work
  8. Work dead.
  1. Ensure all work is complete
  2. Ensure all covers and lids are replaced
  3. Remove lock off and warning notices (multi unlock if multiple workers)
  4. Reinstate supply
  5. Turn on equipment locally if possible
  6. Sign off permit to work.
If it is not safe to work - be confident to say NO

For more information contact [email protected]
Stephen Benton - Cool Concerns
Stephen Benton
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