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Title: Rationalised control gear for bigger markets

Pages: 30 - 31

      

Author: E. Glyn Price

Text: Rationalised control for bigger markets
by E. Glyn Price
Much motor control gear looks needlessly dull and cluttered. Belmos Peebles Ltd. however, has introduced a new modular range of equipment which is greatly improved in appearance, as well as being more compact and efficient than its predecessors.
In common with much of today's industrial, electrical and electronic equipment, motor control gear appears to the uninformed observer to be nothing more than rectangular metal cabinets with an assortment of knobs, switches and dials scattered about over one face.
While no control gear manufacturers can, of course, be expected to go as far as some computer manufacturers have done in beautifying their products, more attention could be paid to the appearance of this type of equipment. Obviously, motor control gear must be designed primarily to do its job of switching on the power in an industrial plant or process with the utmost safety and efficiency.. It should be easy to maintain and repair, as faulty control equipment can soon bring a factory to a standstill. Because of the high voltages involved, the ease of accessibility for maintenance must be reconciled with elaborate safety precautions. Customer requirements are so variable that complete flexibility of arrangement should also be designed into a system. So it can be seen that the design team is faced with considerable problems, of which the final appearance of the equipment is but one.
Nevertheless, because the industry is becoming more competitive, it becomes necessary for manufacturers to make apparent by its neat and orderly appearance the careful and thorough development work that has gone into a system of control gear.

Rationalised equipment
Belmos Peebles Ltd of Blantyre, Scotland, was founded in 1919 and has been manufacturing industrial motor control gear for about 20 years. For many years the firm has been conscious of the value of a clean functional appearance in its products, and has repeatedly introduced designs well above the usual standard for the industry.
When the design of a completely new range of compact motor control gear was begun in 1964, the opportunity was again taken to improve the appearance of the equipment as a whole. As soon as basic technical specifications had been settled, chief engineer David Jelley called the company's consultant industrial designer, Ronald Homes, into the development team. Mr Homes worked with the team to produce basic proposals for a modular system of arranging the panels, a two tone grey colour scheme for the cabinets, and a novel and ingenious method of locking and withdrawing the individual motor starter compartments. Thus a basic visual framework became established for the new equipment, and technical development work could then proceed on complementary lines.
The colour scheme of a medium grey for the cabinets and a light grey for the starter compartment panels was chosen to be deliberately neutral so as to fit well with any building in which the equipment is installed. Bright red and green start/stop buttons relieve this otherwise restrained scheme and give a result which is attractive and well balanced. The controls are placed on the panels in a simple 'L' format which allows a place for every possible item: although it is rarely the case that all will be required by a customer, every situation has been allowed for.
One of the most interesting features of the new equipment is the method adopted for opening the motor starter compartments. These are normally banked in fives or sixes, and it is a maintenance requirement that each starter must be accessible without disturbing the rest of the equipment. Previously this was achieved by having a door on the compartment, complete with unsightly chrome lock and handle, and the maintenance engineer had to work on the compartment in situ. With the new equipment, however, each compartment slides out like a drawer and can be repaired on the bench.
The requirements of locking and opening the larger motor starter compartments have been neatly combined into a simple handle which lies flush with the panel to lock the compartment but swings out to form a handle when the drawer is to be withdrawn. A simple mechanical interlock makes it impossible to open the drawer unless the power is switched off. When the handle is flush with the panel, it forms a neat frame to the compartment label. The switches which isolate each of these larger motor starters from the power supply have also been redesigned and now lie closer to the cabinet surface. They are shaped to make them easier to hold.
The smaller motor starter compartments are banked in tens and thus the panel layout is more cramped than that of the larger compartments. Because of this, the functions of the isolator switch, the drawer lock, and the drawer handle have been combined into a simple lever handle with three positions - on, off, withdraw.

Attention to detail
Further pleasing details of the equipment are the new frameless ammeter dials and the neat push button escutcheons, both supplied by Edgecumb Peebles, an associated company. How often has otherwise attractive industrial equipment been spoiled by needlessly prominent black dial bezels or crudely detailed push buttons ? Belmos Peebles can consider itself fortunate in having such close relations with an instrument manufacturer, so that components can be tailor-made to its specific requirements.
The careful detailing of these components, and of the indicator lights, greatly helps the overall appearance of the cabinets, as does
the almost complete absence of bright chrome plating. Items such as the compartment handles and the isolator switches are finished in aluminium paint, so the panel is devoid of distracting highlights and it is easier for an operator to see what needs to be seen. The starter panels are sensibly laid out so that information areas (ammeters and labels) are white and control areas black.
This small concession to ergonomics does not indicate, however, that much emphasis has been put on the ergonomic aspects of the design. Motor control gear normally requires so little attention that it was considered unnecessary to treat the design as an ergonomic exercise, and as a result some switches and controls are placed much lower and higher than would normally be considered acceptable. The pressure to get the maximum amount of equipment into the minimum floor space was thought paramount.
Skilful mechanical and electrical design work has reduced the size of the new equipment to about two thirds that of its predecessor. Without an industrial design contribution this could have led to congested and confusing control panels; however, co-operation between the industrial designer and the engineering team, and careful detailing and systematic layout, have ensured that the new equipment looks smart and businesslike as well as being functionally efficient.
New flow-line methods of production, with more bench subassembly, have allowed Belmos Peebles to keep production costs to a minimum, and it seems certain that the overall result will be an increasing slice of the world markets for this type of equipment for the company. This is not the first time that a company in the Bruce Peebles Industries Group has used a prominent industrial design consultant, and we look forward with interest to further examples of such collaboration.

Facts about Belmos Peebles
Belmos Peebles Ltd. with Edgecumb Peebles Ltd. had a turnover of 2 8 million in the year ending September 1965. (The turn over for the whole Bruce Peebles Industries Group was 9 million.) The labour force for the two companies is about 1,250.

(caption)
The layout of the front of each compartment makes the controls easy to see and operate. The 'L' format on the large compartments allows a place to be found for any item that the customer might wish to incorporate.]

(caption)
Careful detailing and a systematic layout have resulted in a neat and orderly appearance for the new motor control gear. The size has been reduced to about two thirds that of previous equipment.]

(caption)
To make maintenance easy, each of the compartments can be pulled out like a drawer and taken away for repair at the bench. The drawer cannot be opened unless the power is switched off.]


 

 

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