STANDARD SPECIFICATION FOR — IEC LOW VOLTAGE MOTOR CONTROL CENTRES (BUS-dc713940)

STANDARD SPECIFICATION FOR IEC LOW VOLTAGE MOTOR CONTROL CENTRES TABLE OF CONTENTS SCOPE CODES AND STANDARDS CONSTRUCTION DRAWINGS AND DATA INSPECTION AND TESTING ATTACHMENT A - INTERNATIONAL STANDARDS ATTACHMENT B - OUTDOOR ENCLOSURES SCOPE This specification covers the design, manufacture and testing of an industrial type metal-enclosed factory assembled motor control centre (MCC) for use in electrical systems of up to 1000V and in accordance with the IEC standards. When the MCC is to be provided as an integrated switchboard/MCC, this specification shall be read in conjunction with the specification for low voltage metal enclosed switchgear. Throughout this specification reference is made to “specified elsewhere” or “as specified”. Details for requirements of this type are to be found on the single line diagram or data sheet as appropriate. CODES AND STANDARDS MCCs shall be designed, manufactured and tested in accordance with the latest applicable sections of the IEC standards detailed in Attachment A. The word `should' shall be replaced by the word `shall' wherever it appears in the referenced standards. Any conflicts between the referenced documents shall be identified to the Buyer in writing for resolution. In general the order of precedence shall be: Single Line Diagram and schedules. (When reference to the single line diagram is made in the following part of this specification, it shall be deemed to include reference to the associated schedules.) Data Sheet (if used) Material Requisition This Specification Referenced Standards CONSTRUCTION Service Conditions MCCs shall, in all respects, be suitable for operation under the service conditions stated on the single line diagram. MCCs shall have a design life of at least 20 years and periodic maintenance interval of greater than 4 years. Electrical System The electrical arrangement of the MCCs, including protection, metering, control, interlocking, inter-tripping, shall be as shown on the single line diagram. All components of MCCs shall be rated for the electrical system characteristics shown in the single line diagram. Special reference is made in respect of enhanced circuit making requirements and the d.c. component of fault current at breaking. Whenever possible rated voltages and lightning impulse withstand voltages shall be selected from the standards listed in Attachment A. Structural And Mechanical Requirements Cubicles shall be metal-enclosed, free standing, floor mounting, flush fronted and arranged to form a single structure with a common busbar assembly. Enclosures shall not exceed a height of 2.5 m. Assemblies shall be form 4 construction to IEC 60439 busbars shall be separated from functional units by means of rigid barriers. Terminals for field cabling associated with each functional shall be outside the functional unit and physically separated from the functional unit and other terminals by barriers or within individual cable boxes. The MCC shall consist of motor starters and feeder units, which shall be housed in individual functional units. Unless specifically indicated otherwise a functional unit shall control only one motor or one feeder circuit. Busbars and MCC sections shall be arranged to permit future extension at either end, except for ends with transitions to other types of equipment Structures shall be self-ventilating. Where there is a requirement for louvers or forced ventilation filters shall be installed and the specified IP rating of the panel maintained. Interlocks and covers shall be provided to prevent incorrect or unsafe operation, and to prevent access to live parts. The MCC shall be designed and constructed to facilitate inspection, cleaning, repair and maintenance and to ensure absolute safety during such work. It shall be possible to work safely within individual compartments whilst the remainder of the MCC is energised. Similar parts and components shall be interchangeable. The enclosure shall have a degree of protection as specified on the one-line diagram. When the MCC is specified to be in an outdoor enclosure, the additional requirements of Attachment B to this specification shall apply. Any non-equipped spare compartments shall be arranged such that they can be fully equipped without de-energising the MCC. The withdrawable devices shall be provided with a carriage arrangement to permit their movement, by one person, within the switchroom. Construction, including cable entry, shall be vermin proof. All cover plates that exceed 0.7 m2 that require removal for installation or maintenance of the equipment shall be equipped with lifting handles and self-supporting lips. With the exception of the backs of panels cover plates shall not exceed 1.1 m2 in area or 27 kg in weight, unless they are hinged and bolted or locked. Cover plates shall be secured using captive bolt fixings. All doors, hinged covers, and hinged panels larger than 0.36 m2 in area shall open at least 95o and be equipped with doorstops to hold them in the open position. All such doors and hinged covers shall be equipped with handles and secured by captive bolts, lockable with a key or padlockable. Enclosures shall not have sharp edges or pointed objects, such as the pointed ends of sheet metal screws, on the exterior, inside any wireway, or in any access space required for installation, operation, or maintenance. Operating devices, handles, push buttons, lamps and indicating instruments shall be located above 0.3 m and below 1.9 m form the finished floor level. Where access is described as front only no part that may require maintenance replacement alteration or inspection during the life of the panel shall require rear access. This requirement includes all busbar connections and small wiring. Motor Starters Motor starters shall be direct on-line unless specified otherwise. They shall be arranged for local and remote control. Motor starter shall be one of the following: Swing out pattern with all or some components door mounted. Withdrawable. In this case the rating of the plug-in contacts need specific approval of the buyer. Fixed pattern with components fixed within compartment. The Buyer shall approve maintenance access. Each motor starter shall consist of: A fuse‐combination unit. Alternatively a moulded case circuit breaker (MCCB) may combine the protection switching and isolation functions. Air break contactor. Motor protection relay. All other devices for the protection and control of the motor specified elsewhere. Indicating lamps, `Red' for motor running, `Green' for motor stopped, on the compartment front cover. Motor starters shall comply with 60947-4-1 Type 2 co-ordination being tested at prospective short circuit currents “r” and “Iq” and as detailed in Attachment B4 of above standard. Test facilities shall be provided to permit operation of the motor controller without energising the power circuit. The test facility may be by means of a pull to test button located inside the compartment or by means of an additional position on the isolation device. It shall only be possible to select the test position when the compartment door is open, it shall be automatically reset when the compartment door is closed or it shall not be possible to close the door with the test function engaged. Feeders And Distribution Circuits Feeders and distribution circuits shall be one of the following: Withdrawable. In this case the rating of the plug-in contacts need specific approval of the buyer. Fixed pattern with components fixed within compartment. The Buyer shall approve maintenance access. Each feeder and distribution circuit shall comprise of components specified on the single-line diagram including: A fuse‐combination unit with the number of poles indicated. Alternatively a moulded case circuit breaker (MCCB) may combine the protection switching and isolation functions. Air break contactor for contactor controlled circuits. All other devices for protection, indication and control specified elsewhere. Component Mounting Plates All components shall be fixed to the component mounting plate and not to the compartment sides or base. Component mounting plates shall be adequately protected against corrosion. Where plates are not painted for EMC reasons they shall be galvanised, where plates are painted they shall be white. The minimum thickness of any component mounting plate shall be sufficient to engage at least two full threads of any fixing. Fixings for components and component mounting plates shall not penetrate into busbar compartments or other compartments containing live parts. Fuse Combination Units Fuse‐combination units shall be fuse switch disconnectors or switch fuse disconnectors. The Fuse‐combination unit switch function for motor circuits shall be fault make and capable of breaking the motor locked rotor current, have a performance equal to uninterrupted duty AC-23B utilisation category according to IEC 60947 and shall meet the isolation requirements specified for a disconnector. The Fuse‐combination unit switch function for feeder and distribution circuits shall be fault make and capable of breaking the circuit full load current, have a performance equal to uninterrupted duty AC-22B utilisation category according to IEC 60947 and shall meet the isolation requirements specified for a disconnector. The disconnector function shall be mechanically interlocked with door/withdrawal mechanism and be padlockable in the ‘open’ position. It shall not be possible to open the compartment door when the disconnector is padlocked open. For withdrawable equipment it shall be possible to padlock the compartment to prevent insertion of the equipment. Fuse‐combination units shall be fitted with auxiliary contacts for internal/external isolation, control and indication. MCCBs affording the same protection, switching, isolation and control functions as the specified fuse-combination units are an acceptable alternative. MCCBS included in this application in conjunction with motor starters shall be current limiting. Fuses Main circuit fuses shall be of the high rupturing capacity (HRC) type and have a motor protection characteristic performance in accordance with the specified codes and standards. Control, indication and instrument circuits shall be protected by HRC fuse disconnectors. All unearthed poles of auxiliary supplies shall be fused. Earthed poles shall be connected by a removable link. The removable link in the earthed poles shall not be interchangeable with the fuses in other poles. MCBs affording the same protective and isolation function as control fuses and links are an acceptable alternative. Contactors Contactors shall be air break, electro magnetically operated unless otherwise specified, and complying with the listed codes and standards. Contactors shall be electrically ‘held’ unless otherwise specified. The coil voltage shall be as specified with the minimum voltage to pull in and maintain no lower than 85% of the nominal control voltage. The contactor shall not drop out at any voltage above 60% of the nominal control voltage. At the full load specified contactors shall have a utilisation category AC-3 to IEC 60947 for motor starters and an AC‐2 utilisation category for distribution circuits unless a more onerous duty is indicated for the circuit. Contactors shall be rated for the equivalent uninterrupted and a 60 % intermittent duty class 12 of IEC 60947. Mechanical interlocks shall be provided where it is necessary to prevent the simultaneous closing of contactors (for example forward and reverse). Where contactors are of the mechanically latched type it shall be possible to trip mechanically the contactors at the MCC. Motor Protection Thermal, three-phase overload relays incorporating single phasing protection and ambient temperature compensation shall be provided. For currents up to 20 A the relays may be direct connected. Motor protection relays may include the thermistors or the RTD input in the main relay. For motors having a full load current above 63A earth fault protection shall be provided and include a delay to prevent operation for transient currents and operation of the contactor for currents above its breaking capability. Motor protection relays for motors over 10 kW shall be of the electronic type that include for adjustment of the motor tripping current, the tripping time and the cooling time of the motor. Motor protection relays for motors over 75 kW shall be of the solid state type, microprocessor-based and mounted in a modular, flush fronted case. Relays shall have provision for external interrogation/set point adjustment via a laptop computer. Relay test and setting software, including interface leads, shall be provided. The relays shall offer a full thermal modal of the motor and facilities for adjusting the stall time heating time, cooling time and the tolerance of the motor to out of balance conditions. Where appropriate motor protection relays shall be fully configured by Seller in accordance with single line diagrams and MCC schedules prior to the factory acceptance tests. Details of relay configuration shall be supplied to Buyer in both hard copy and electronic formats for review before commencement of tests. Protection relays shall have hand-reset facilities and clear operating indication, e.g. light emitting diodes. Non-tripping relays may be self-resetting if an indication of operation remains until hand reset. Relays with multiple trip and alarm functions shall have separate operating contacts for each function wired out to separate terminals. Busbars Busbars and connections shall be manufactured from hard drawn copper and shall be of the same cross sectional area throughout the length of the MCC. Phase and neutral busbars shall be run in a common compartment containing no other equipment or wiring and not requiring access for any other purpose. Busbars shall be marked to indicate the phase colouring, which shall be red, yellow, blue and black unless otherwise specified or explicitly precluded by relevant national standards. The vertical and horizontal busbars and connections throughout the switchboard/MCC, including adaptor chambers, shall be adequately sized, braced and supported to withstand the mechanical forces and thermal effects resulting from the rated short circuit current and shall carry certification from a recognised Testing Authority. The length of any cable connection, sized on the basis of a short circuit on the load side of the respective short circuit protective device, such as a connection from a busbar or dropper to a functional unit terminal, shall be less than 600 mm. An earthing busbar shall be provided along the full length of the structure with provision for earth cable connections at each end. Earthing All metallic non-current carrying parts of the MCC shall be bonded together and connected to the earth busbar. All doors shall be bonded to the main structure by means of a flexible copper connection arranged so that it cannot be trapped as the door is opened or closed. All earthing connections on withdrawable equipment shall be first make last break design, parts shall be effectively earthed until they are completely withdrawn with all power and control connections disconnected. Provision shall be made, adjacent to the cable termination, for earthing cable armouring to the earth busbar. Secondary Wiring Secondary wiring shall be PVC insulated 600 V grade with a stranded conductor and minimum conductor cross sectional area shall be 1.0 mm2. Wiring shall be terminated with crimped cable ends or lugs appropriate for the connected terminal. There equipment terminals do not allow the connection of the specified conductor size the connections to fit the equipment shall be wired to adjacent terminals for transition to the specified wiring size. Secondary wiring within the MCC shall be carried out in a neat and systematic manner and securely held in position (either loomed or run in conduit/trunking). Where wiring passes through compartments it shall be run in conduit/trunking that, if metallic, shall be bonded to the main frame. The layout of the wiring shall be such that individual components can be readily removed without removing other components or sections of secondary wiring. Secondary wiring layout shall permit alterations to individual circuits without requiring shutdown of the complete MCC. Bus wires for control, indication, heaters etc. shall be run within the MCC and individually fused. Wiring identification shall be by numbered and/or lettered interlocking sleeve ferrules, of insulating material, adjacent to the terminals. Ferrules shall be indelibly marked and removal without disconnecting the wire from its terminal shall not be possible. Flexible cables shall be used for connections on door mounted equipment. Wiring shall be loomed, wrapped in flexible PVC conduit and be firmly clamped at both ends to prevent movement at termination's. All wiring for external connections or between functional units in the MCC shall be brought out to individual terminals on a readily accessible terminal block. Terminals shall be of the disconnector type to facilitate testing. No more than two wires shall be connected to a terminal. Cable Terminations Cable terminating facilities and terminals shall be suitable for the specified cable type and conductor size. Terminal blocks shall be arranged and positioned to afford easy access for carrying out external cable termination, testing, inspection and maintenance. There shall be ample clear space allowed between the terminal block and the glandplate for the spreading and termination of external conductors. Terminal blocks shall be mounted in a single deck arrangement. The panel wiring shall be in one side of the terminal block only. All terminal blocks shall be shrouded or provided with transparent covers. Pinch screw type terminals are not acceptable. Terminals for different voltages shall be separated by partitions. Cable supports shall be provided by the Seller to avoid undue strain on the cable termination. Termination of single core cables shall be through a non magnetic metal panel or gland plate and provision made for bonding and earthing any armour and/or concentric earth conductors. Cable terminal arrangements for power and control cables may be integrated provided that a barrier separates the two. Auxiliary Supplies The coil voltage for contactors shall be derived from a double wound isolating control transformer connected phase-to-phase in the individual functional unit unless otherwise specified. Test supplies shall be wired form a common test supplies transformer for the panel. The test supply shall be bus wired through the panel to the individual functional unit. Test supplies derived from a phase-to-phase connection in the functional unit are not acceptable. Tripping supplies for latched contactors shall be supplied from suitably rated dc supply units. Where dc supply units are not in the Sellers scope, then the Seller shall specify the standing load, peak load and permissible voltage variation. For shunt trip circuits the protection shall be rated at least 300% of the load requirement. All bus wired auxiliary supplies and test supplies shall be individually fused/protected within each functional unit. Anti-condensation heater supplies shall be fed from a single source for each busbar section. Motor heaters and mcc heaters Instrument Transformers Current transformers shall be provided as shown on the single-line diagram or otherwise required for use in connection with the selected protection and control equipment. The Seller shall provide details of ratio, output, class and accuracy for all instrument transformers in the Seller’s supply. The secondary windings of instrument transformers shall be earthed at one point through a removable link, with provision for attaching test links. Current transformers shall be rated to withstand the thermal and magnetic stresses resulting from through fault currents equal to the MCC fault rating taking into account current limiting effects of protective devices. Shorting terminals for current transformers shall be provided at the outgoing terminals where external connections are required. Voltage connections to instruments and relays shall be protected by HRC fuses. Instrument transformer nameplates shall be fixed in a position so that details can easily be read when fitted in the cubicle. Metering And Indication Metering, protection and control shall be provided as shown on the single-line diagram. Meters shall be flush mounting and fitted on the front of the MCC. Unless otherwise specifically indicated meters shall be the 96mm square type for incomers and busbar indications with the 72mm size for motor starters. Directly connected ammeters and other instruments are acceptable for circuits with full load currents below 25 A. Above 25 A current transformers shall be used. External zero adjustment shall be possible on all indicating analogue instruments to facilitate adjustment without dismantling the instrument. Ammeters shall be scaled such that full load corresponds to between 50 and 80% of the angular deflection. Ammeters for motors shall have a compressed overload scale and a red line shall indicate motor full load current. Meters and relays shall be capable of withstanding without damage the secondary currents associated with the MCC rated fault current flowing in the primary of current transformers taking into account current limiting effects of protective devices. Unless indicated otherwise low voltage equipment voltmeters and voltage coils shall generally be direct connected. Ammeters and voltmeters shall be class index 1.5. Watt-hour meters and maximum demand meters shall be class index 2.5 for indication and accuracy class 1 for measuring supplies to/from third parties. Relays And Timers Relays and timers shall have dust proof covers. Relay bases shall be keyed to ensure correct contact alignment and shall include retaining clips for the relay. Where similar relays and timers are used for different coil operating voltages they shall be non interchangeable. Relays shall have a means of visually indicating they are energised. Timers shall have indication that they are energised and that the timing is in progress. The coil voltage shall be as specified with the minimum voltage to pull in and maintain no lower than 85% of the nominal control voltage. The relay shall not drop out at any voltage above 60% of the nominal control voltage. Indicating Lamps, Push Buttons And Selector Switches Indicating lamps shall be 22 mm diameter type. It shall be possible to replace the lamp element from the front. Lamp elements shall be either multi cluster LED type with or without a transformer, transformer type lamps or 24 V filament type for 24 V circuits. Push buttons shall match the indicating lamps in style. They shall be 22 mm type. Control and selector switches match lamps and push buttons in style. They shall be 22 mm type The number of contact blocks on each push button or selector switch shall be limited to two. Relays shall be used if additional contacts are needed. Anti-Condensation Heaters Thermostatically controlled heaters suitably rated to prevent condensation shall be provided within the MCC. A heater shall be provided in each functional unit unless otherwise specifically indicated. Heaters shall be shrouded to prevent inadvertent contact or shall be of a type where the maximum surface temperature is safe to touch. Heaters shall be connected so that they are in service when the functional unit is in the test position. Motor anti-condensation heaters (when specified) shall be controlled through a fuse and the auxiliary contacts of the disconnector and contactor. The heater shall be energised when the motor is stopped. The motor anti condensation heater shall be totally isolated when Main Circuit disconector is open. Labels Labels shall identify MCC cubicles, compartments and components. Nameplates, rating plates and labelling of equipment and wiring shall be in accordance with the relevant Standards. Functional unit label designations shall belocated at front and rear of panel and shall be in accordance with the single-line diagram. All withdrawable components shall have a circuit label. Each device including relays, meters, push buttons, lamps, fuses, contactors, and timers shall be clearly labelled to indicate its purpose. Labels shall be positioned to provide easy identification and correspond to the designation on the panel drawings. Such labels shall have minimum lettering sizes of approximately 6 mm high for external labels and 4 mm high for internal labels. Fuse labels shall show the rating of each fuse. Where devices such as push buttons are attached to doors, a label with the same designation shall be fixed to the reverse (panel-wiring) side. Internal labels shall be secured adjacent to the equipment but not on removable covers. They shall be positioned to allow replacement of labels, equipment or fixings. Internal labels may make use of a durable proprietary ladling system unless specifically indicated otherwise. External labels shall be engraved on laminated plastic and attached with screws and nuts or screws into tapped holes. Where the label is longer than 100 mm, holes shall be elongated and provided approximately every 100 mm. A main nameplate shall be affixed in a prominent position on each MCC giving the following information: Manufacturers name and type. MCC Tag Number System voltage, phases, wires and frequency. Rated fault current. Busbar rating. Year of manufacture. Purchasers name. Order Item No. Each circuit shall be fitted with a label giving the equipment tag number and circuit description. Labels shall have black characters on a white background. Danger labels shall have white characters on a red background. Warning labels shall have black characters on a yellow background. Labels shall be made of a non-corrodible material. Finish The colour and finish shall be in accordance with the Manufacturers standards for the service conditions specified. Accessories A complete set of any special tools required for operation, maintenance and testing of the MCC shall be provided. A suitable storage box or wall mounted rack shall be provided. DRAWINGS AND DATA The Seller shall provide drawings and data in accordance with: The purchase requisition and its attachments including "vendor drawing and data requirements". Instructions to Sellers. Type test certificates supplied shall be for each design and rating of MCC. Tests shall be those listed in the relevant standards. The tests shall be for the precise cubicle configuration proposed, including any adaptor units such as between switchgear and MCC. INSPECTION AND TESTING 5.1 The Buyer reserves the right to witness the following tests: Routine tests on all MCC/components as specified in the relevant standards (refer to clause 2.0). Operational (electrical and mechanical) tests on all components. Protection operation by primary injection of current and voltage as required. Verification of availability and correct operation of all protection and control functions within all protection relays. Interchangeability test. Type tests where carried out for this application. (Certificate for witnessed tests shall be available for signature on the day of the test.) 5.2 The Buyer reserves the right to inspect the MCC at the manufacturer's works prior to despatch to prove compliance with specification. ATTACHMENT A INTERNATIONAL STANDARDS IEC STANDARDS IEC 60044-1 Instrument transformers. IEC 60051 Direct acting indicating analogue electrical measuring instruments and their accessories. IEC 60073 Basic and Safety Principles for Man-Machine Interface, Marking and Identification - Coding Principles for Indication Devices and Actuators. IEC 60186 Voltage transformers. IEC 60255 Electrical relays. IEC 60269 Low-voltage fuses. IEC 60417 Graphical symbols for use on equipment. IEC 60439 Low-voltage switchgear and controlgear assemblies. IEC 60445 Basic and Safety Principles for Man-Machine Interface, Marking and Identification - Coding Principles for Indication Devices and Actuators. IEC 60521 Alternating current watt-hour meters. IEC 60529 Degrees of protection provided by enclosures. IEC 60715 Dimensions of low-voltage switchgear and controlgear. Standardised mounting on rails for mechanical support of electrical devices in switchgear and controlgear installations IEC 60947 Low-voltage switchgear and controlgear. IEC 61000-4 Electromagnetic Compatibility (EMC) IEC/TR3 61641 Enclosed LV switchgear assemblies - Guide for testing under conditions of arcing due to internal fault ATTACHMENT B OUTDOOR ENCLOSURES B.1 Enclosures shall be weatherproof and be fabricated from free-standing steel frames and steel panels with doors formed to provide a strong and rigid structure and with the degree of protection as stated on the single-line diagram. B.2 Gaskets shall be held in metal containers (e.g. channels). The roof shall be sloped to provide drainage in a direction away from the doors. B.3 Removable panels shall be secured with captive slotted or shaped-head fasteners, machine screws or machine bolts engaging captive nuts or tapped holes in structural members. Self-tapping sheet metal screws shall not be used. B.4 Walk-in (protected aisle) enclosures shall be provided with a 750mm minimum width outer door at each end, each fitted with inside, quick-release latch mechanisms and with flush, cylinder-type locks. All cylinders shall be operable by the same key and shall be of the type as specified. B.5 Aisle-less enclosures shall have individual outer doors of 600mm minimum width for each section. Doors shall have provision for padlocking. B.6 Door stops shall be provided to maintain doors in the open position and a stop release shall be provided no higher than 1.8m above the floor. Door latches shall engage the steel frame at three points (top, bottom and side) to latch the doors closed, and shall have a rolling or smooth sliding action when engaging the frame to aid in operating the latches. B.7 All exposed handles, screws, and hinges shall be non-corrosive material, or shall be galvanised. Galvanizing shall not be used for the external components of MCCs that will be installed in corrosive areas. B.8 Enclosures shall have louvered ventilation openings at the bottom, unless designed to be non-ventilated. Such openings shall be equipped with replaceable filter elements. The filter elements shall be accessible for replacement while the equipment is in normal service. B.9 When specified, thermostatically controlled ventilation fans and/or heaters shall be provided to maintain a preset maximum/minimum temperature within the enclosures. B.10 Enclosures shall be provided with a totally enclosed base constructed of 100 mm minimum channel or I-Beam. Panelling shall stop a minimum of 75 mm above the bottom of the base. Enclosures shall be undercoated with a material which is suitable for the specified service conditions and which is tough enough to withstand the rigors of transportation without damage B.11 Enclosures shall be primed and chemically treated to prevent rust, and painted inside and out per manufacturer's standard unless specified otherwise. B.12 Illumination controlled by toggle or door switches shall be provided in all outdoor equipment, unless otherwise specified. Switches shall be identified with engraved nameplates. Two-way switches for fluorescent lighting in protected aisle enclosures shall be located beside the door at each end. Minimum illumination shall be 300 LUX on the vertical panels 1m above the floor. B.13 At least one receptacle power outlet shall be provided inside each outdoor enclosure. Where an outdoor assembly includes four or more vertical sections, at least two receptacles shall be furnished, one at each end. Maximum distance between receptacles shall not exceed 9 m. B.14 When external power is specified for space heaters, lights and receptacles, isolating switches or circuit breakers shall be provided for each circuit. These devices shall be completely wired and connected to readily accessible, isolated terminal strips for connection of external power wiring. All wiring in the same cableway shall be insulated for the highest voltage wire in the cableway. PAGE PAGE 1 OF NUMPAGES 17