DEALING WITH ELECTRICAL DANGERS IN OLD ORGANS
 

 

The issue of electrical safety is one that we take very seriously indeed, especially since there is little or no assistance to be sought elsewhere which would give clear and sensible guidelines to help us in our renovation work. We try to combine those safety stipulations that are applicable today, with our own detailed experience of what each model's weak points are. We then work this together with a measure of common sense, a regard for economic limitations and a degree of over-caution. This melting pot of underlying factors is the basis for our own set of guidelines to help us design each piece of renovation work. Fragments of these guidelines can be found spread out in various other documents on this web-site; here they are collected and clearly listed. The instruments we procure in order to renovate, are often ones which have been lying idle for quite some time, in which case their state of electrical security has been of minimal interest. Suddenly, after renovation and delivery to the (eager) customer, each instrument will find itself being played day and night for months on end, sometimes years on end! A very important part of our job is to see that this new lease of life is as trouble-free as possible, and much emphasis is placed on the elimination of electrical hazards.

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Switches of any kind which control mains voltage must have two poles, breaking both live and neutral lines. This is particularly important in continental Europe, where mains plugs are reversible. Difficult though the task is, even the special 'start' and 'run' switches used on all models until the mid sixties must be replaced by two pole versions.

 

Specially made two pole run and start switches.

In the space between the switches' solder terminals and the metal chassis beneath, an insulating 'floor' must be moulded.

* An indicator lamp must be connected directly after the main switch, to clearly show when the instrument is switched on. Leslie cabinets, whether powered by the organ or by a separate mains cable, must also have such an indicator lamp mounted on the front side. Lamps having a minimum-protrusion lens are preferable. Many organ models including ABC and related models, have an indicator lamp connected directly to the 6.3v~ heater supply for the valves. This should be disconnected since it is rendered superfluous by the new lamp, and also because it has a habit of short-circuiting at the solder joints on the lamp holder.
* Mains cables should, wherever possible, be of the detachable kind (Euro cable) having all three conductors; live, neutral and earth. These are available in a useful variety of lengths, colours, and entry angle of plug/socket. Damage to permanently attached mains cables is very common, especially on organs which are often moved.
* The mains wiring within the organ must be inspected with the utmost care, looking for; (a) chaffed insulation where wires pass over sharp chassis edges, (b) loose solder joints and looses screw terminals, (c) solder joints that are too close to the metal chassis, (d) old wiring with hardened insulation which cracks when handled. This is prevalent with the brown, two core lead-in flex found in many organ models.
* All systems of controlling the speed of Leslie motors prior to the introduction of transistorised models must be entirely abandoned, replacing them all with modern solid state relays controlled by low voltages.
* Wherever possible, the practice of providing a Leslie with its mains power from the organ via the multicore cable should be avoided. The Leslie should have its own mains power system comprising detachable cable, euro socket, main fuse, mains switch and indicator lamp. In domestic applications, where there is an appreciable risk of forgetting to switch the Leslie off, its mains power should be relay controlled from the organ. In Scandinavia, where Leslies have their own mains power cable and a concealed power switch, they are often worn out due to repeatedly having been inadvertently left on.
* An effective system of fuses must be put in place, to protect against the consequences of malfunction, overload and, as far as possible, misuse. This typically consists of three fuses; a main fuse, an anode supply fuse, and a fuse for the motor circuits. Modern multi-channel Leslies have a very large current surge at switch-on, making the use of fuses ineffective. Here, a thermal cut-out is used instead, since this withstands a large surge which otherwise blows a fuse.
* Scandinavia only - WARNING! During the 60's and 70's a large number of 'safety' modifications were carried out on Hammond organs and Leslie cabinets at the instigation of the electrical safety and testing authorities, as a precondition for marketing these products in Scandinavia. Paradoxically, many of these modifications created electrical hazards (e.g. exposed and un-insulated fuse holders connected to 960v~!) which are far worse than the supposed hazards they were rectifying. This matter is discussed in detail using the Swedish language, in the document "Hammondorglar i Kyrkor". If you own a Hammond or Leslie modified for Scandinavia before 1980, you are urged to carefully read the discussion on safety in that article. Further, if you know of any one else owning such equipment, please draw their attention to this matter.

In our opinion, it is the organ engineer, or the renovator, or the shop selling the item, who carries responsibility for the electrical safety of the item passing through their hands, since it is unreasonable to assume that the customer has any detailed knowledge of these matters. In other words, it is the last in line of people making money on the item who must make sure it is safe. For our own part, we would decline an assignment of repair or renovation if the customer denied us a free hand to improve safety aspects of the equipment which we knew to be hazardous. Happily, this situation has never arisen, and all products leaving our workshop are augmented with the above safety measures. The rules and regulations concerning consumer rights in Europe are very tight indeed, and we go to great lengths to observe these. We would vigorously encourage other suppliers to do likewise!