The importance of electrical diagrams
Electrical diagrams are vital for any factory for the same reason that makes them mandatory for aircraft or nuclear plant operators: personnel safety.
Although the importance of electrical diagrams cannot be over-emphasised, there are other reasons for using them which may not be as obvious.
Safety of machinery
For example, interlocks intended to protect expensive machinery can be a “nuisance” to the production department which, in turn, requests that they be bypassed. Without proper drawings, the electrician will “bridge it out” completely, as this is usually the path of least resistance.
However, with proper drawings, the electrician could:
- Have a better understanding of the reasoning for the interlock.
- Consider modifications which will retain the interlock but remove the nuisance it causes.
- Be less inclined to take the responsibility of exposing the machine to risk for the sake of saving potential call-outs.
- Be more inclined to report his actions.
Downtime savings
Diagrams are a prerequisite for methodical and rapid fault-finding. The process of elimination can be very time consuming and, on even slightly complicated equipment, the chances are that the electrician will unwittingly create more faults and compound the problem. This is a fact any experienced troubleshooter will confirm.
Improved productivity
Investigations into the comparative number of electricians employed by similar factories within one group showed great disparity, and it was by no coincidence that the factories employing the most staff had the least drawings.
It is commonly accepted that the productivity of a new electrician will be very low during his initial months due to the need to acquire sufficient “plant knowledge”. This time can be reduced drastically if the electrician is presented with a comprehensive set of diagrams prepared specifically for the maintenance of the appropriate electrical plant (as opposed to diagrams prepared for the manufacture of equipment).
Fig. 1: Electrical diagrams are essential to rapid fault-finding.
Training
Factories rely increasingly on automation while good electricians who are prepared to do maintenance are becoming very scarce. The opposing trends must compel every industry to give the matter of training and upgrading urgent attention.
However, the efforts will prove embarrassing and quite dangerous unless accurate drawings are available.
Staff turnover
Firstly, good electricians (who can read circuit diagrams) consider diagrams as part of their working conditions and will be frustrated very quickly if they are expected to work in the dark, without proper diagrams. You therefore stand a better chance of retaining a good electrician if your diagrams are in good order.
The lack of diagrams is quite often exploited by electricians who have acquired intimate plant knowledge over the years. They keep the knowledge to themselves. The feeling of being indispensable is presumably their motivation. Such employees can try to hold a company to ransom or cause significant loss of profits.
Why sub-standard diagrams?
This should raise the question of why electrical diagrams are not up to standard. Some of the reasons for this are:
Cost
Manufacturers and designers of plant always have their hands full trying to meet target dates and to contain costs. Their resources and funds must be directed to these ends if they are to survive in the very competitive electrical business. Your documentation therefore features low on their priority list, if at all. The end-user can also seldom justify the expense of an electrical draughtsman to generate and update the documentation.
Responsibility
The average manufacturer seldom volunteers good documentation. One has to fight for it but who should do the fighting? The person directly affected is probably the electrical foreman but he or she seldom has the authority or support to back their demands. It is too late once the suppliers have their money.
It is never an easy task for the chief engineer of the plant to know who should be made responsible for the maintenance of electrical documentation in the absence of a draughtsman.
Complacency
Electrical plant is inherently very reliable and downtime caused seldom exceeds mechanical causes. Nonelectrical people must therefore be forgiven for failing to appreciate the need for electrical maintenance, let alone documentation. However, it is the inherent reliability which makes documentation so much more important. The interval between faults can be very long, rendering the memory useless and making reliance on up to-date documentation essential.
Solution
The answer lies in using outside organisations, specialised in this field, to tackle the problem with some aggression and profit motivation. The end-user can easily monitor the costs and will find that an outside organisation will provide the most economic and effective solution.
Finally, there is the question of providing staff with maintenance orientated documentation as opposed to diagrams and tables issued for the purposes of manufacture. The difference can be very significant indeed.
Contact Dave Leigh, Matra Engineering Services, Tel 044 386-0032, dave@matra.co.za
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