Motion Picture Herald (Mar-Apr 1945)

The Show Must Go On... AND DOES with a Robin-Imperial STEDYPOWER {Built by Imperial Electric Go.} Not just a motor-generator but a guarantee of service — a power plant with 55 years' electrical know-how and 35 years' theatre experience "built in." Designed specifically for use with direct current high intensity arcs by men who know your needs. The best means of avoiding arc power failures which aggravate patrons, make refunds necessary, and fine chairs, air conditioning and good pictures meaningless. Liberal over-load capacity. Sparkless commutation. Quiet operation. Voltage holds constant during change-overs. Built in all ratings and combinations. Your Independent Theatre Supply Dealer will help you make application for a STEDYPOWER if yours is one of the many theatres now qualifying. Write for literature. J. E. ROBIN, INC. 3 30 W. 42™ St. , New York City Motor-Generators and Motors for Every Requirement emphasis on the motor-generator set, and all driving motors of the ventilating or air-conditioning equipment, as well as curtain control motors and special lift motors on the stage above one horsepower. Similar provisions should be made for feeding the general interior lighting, marquee lighting, any lighting of the stage (such as the stage switchboard, footlights, borderlights, floods, etc.), as well as emergency lighting. • In figuring the feeders to the projection room it is well to look into the future to try to foresee what possible changes might come about in the present-day projection equipment before the wires and conduit are bound permanently. Provisions should be made in the original installation to every extent feasible, to take care of these future needs, for these will be far cheaper in the long run than to rip out old conduit and wiring later on. The same foresight should be exercised in specifying the conduit and wiring work to be installed in the projection room proper, anticipating a new sound system, television equipment, special lighting, rewinder drives, etc. An architect or designing engineer does not usually consider such things, as they are not of regular concern to him; the theatre operator has to know and say what he wants. In planning the layout for the conduit and wiring runs to the chairs in the auditorium , all present needs for the installation of the aisle lights and hearing aids must of course be met, then allowances made for the possible future installation of such special items. Additionally, however, it might be a good idea, depending on conditions, to provide for future installation of an automatic usher system, special patron call system, automatic control of the volume of the sound from the auditorium. Nearly all past installations of conduit and wiring to the chairs have been done with Yi inch or 24 incn conduit that will accommodate, at the most, only four small wires. It is not much more expensive to run, say, a 1 inch or 1 T/2 inch conduit, with two or three spare wires pulled through, that could be easily connected in case the need should arise later on to hook up some special equipment. In all cases, the use of BX flexible conduit should be avoided in the theatre; only rigid pipe conduit, or flexible Greenfield conduit should be employed. The objection to BX conduit is that it is furnished with the wires inside the flexible shield or armor ; when any breaks occur, due to rough handling or coiling, they cannot be seen until a short circuit develops after installation. In rigid and flexible conduit the wires are pulled through after the conduit is installed. . Feeders for the general lighting panel should run directly to this panel, which should be located in the most accessible place for convenience in everyday operation, preferably in the manager's office safe from the prying hands of any outsider. From this panel, wiring circuits, properly fused and switched, should be run to feed all of the general needs in the theatre, such as curtain controls below one horsepower, lighting fixtures in the auditorium, lobby display frames and shadow boxes, general marquee lighting, including attraction panels, etc. Also, from the main distribution panel board, feeders should be run over to the em\, gency panelboard, which in all cases shot be installed in the manager's office. It is very important that only emergen circuits, each distinctly marked and identify be run from this particular panel. It is jv what the name implies — an emergency pan from which at a given instance all circu connected within can be controlled easily a quickly. All exit and directional signs, em* gency exhaust fans, and special automa fire-control switches should be fed and cc trolled from this panel. It is advisable in all cases that the reco: mendation of the National Fire Protecti Association be followed in the installation all conduit and wiring in theatre work. Thr rules and regulations are revised as necessa every two years, and a copy of them can ' obtained by applying to any city fire inspecti bureau or to the Underwriters' Laboratori However, where there are local codes coveri the installation of conduit and wiring, enact by city or state governments, they should followed rather than the recommendation the National Fire Protection Association, i any case, it is always well to be familiar wi all of the code regulations in force in ord to be in a better position to check the install tion of the electrical work. • Following are some reminders to indica the general practice in planning the illumir tion of a theatre. However, in lighting wo no set rules can fake the place of sound jud ment and intelligent planning. Each illumin< ing job should be considered more or less a problem by itself, to be worked out accor ing to previous experience, actual installatio elsewhere that have proved successful, ide of illuminating engineers, etc. The primary purpose of a lighting install tion is to supply sufficient illumination for tl safety and -comfort of patrons; after th comes the decorative effect. There is, ho ever, a big difference between light at illumination, between, for example, a br liantly lighted auditorium and a well ill minated one. If the objects or areas can \ seen clearly, then the auditorium is w< illuminated', if the light sources are uno trusive and pleasing to the eye, the room well lighted. Accordingly, an area in whi< the lights appear soft and pleasing, and which objects are clearly distinguishable, both well lighted and well illuminated. TF thing to remember in planning a lightir installation is to keep the illumination i objects and areas as strong as necessary f safe, comfortable, efficient activity, but tl brilliancy of the lights as low as possible f such results. • BASIC CONSIDERATIONS IN PLANNING ILLUMINATION i: There are three general systems of illumin; tion. In direct lighting, which has more tha one-half of the light reaching the area to b; illuminated, the light comes directly from th' lighting fixtures without being first reflecte from the ceiling or wall. It is the most eff cient for illuminating floor areas, doorway: stairs and certain objects. The decorativ treatment is less involved in direct lightini Indirect lighting, in which the light is d' rected first on the ceiling or walls or bafHi and then reflected from these areas to tr 2& BETTER THEATRES, MARCH 3, 1945