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section 16 apply on : a) class 1 and class 2 remote control circuits, b) class 1 and class 2 signal circuits, c) class1 extra low-voltage power circuits d) class 2 low-energy power circuits. Rule: 16-000 (scope)
True
Class 1 extra-low-voltage power circuits shall be supplied from a source having a rated output of not more than 30 V and 1000 V.A ( Rule: 16-100)
True
Class 1 remote control and signal circuits shall be supplied by a source not exceeding 600 V. ( Rule-16-100(2))
True
overcurrent protection is not required on the secondary side of the transformer to protect the secondary conductors, but overcurrent protection is required for branch-circuit panelboards. (source: google)
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In class 1 circuits, the overcurrent devices shall be located at the point where the conductor to be protected receives its supply and overcurrent device shall be permitted to be an integral part of the power supply.( Rule: 16-106)
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1000 V.A limitation, class 1 extra-low-voltage power circuit sources including transformers shall not exceed 2500 V.A and product of maximum current and voltage not exceed 10 000 V.A with the overcurrent protection bypassed. ( Rule: 16-108)
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Insulated conductors smaller than no. 14 AWG copper shall be permitted to be used in class1, circuit if, a) installed in a raceway ( an enclosed conduit that forms a physical pathway for electrical wiring) b) installed as a cable assembly; or c) within a flexible cord in accordance with ( Rule: 12-402 )
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subject to the condition, insulated conductors shall be not smaller than a) No. 16 AWG for individual insulated conductors pulled in raceways; b) No. 18 AWG for individual insulated conductors laid in raceways; c) No. 18 AWG for an integral assembly of two or more insulated conductors. (Rule: 16-110(2)
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1.Different Class 1 circuits shall be permitted to occupy the same enclosure, cable, or raceway without regard to whether the individual circuits are AC or DC 2. Insulated power circuits and insulated conductors of class 1 circuits shall not be permitted in the same enclosure, cable or raceway except when they are connected to the same equipment. (Rule: 16-114)
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All insulated conductors of such remote control circuits shall be installed in conduit or electrical metallic tubing or be otherwise suitable protected from mechanical damage or other harmful conditions such as moisture, excessive heat or corrosive action (The proposed infrared or IR remote control circuit can be used to operate an appliance ON/OFF through any standard TV remote control handset)( Rule: 16-116)
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Class 2 circuits, 0 to 20 V, the open-circuit voltage does not exceed 20 V shall have an overcurrent protection rating not exceeding 5 A (Rule: 16-200 (1) (a))
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A circuit does not need overcurrent protection when: a) The current is supplied from batteries and not exceeding 7.5 A after 1 min. b) a transformer or other power supply device having a class 2 output ) a current not exceeding 5 A .
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A device having energy- limiting characteristics shall be permitted to consist of a series resistor of suitable rating or other similar device. ( Rule: 16-200(2))
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A class 2 power supply shall not connected in series or parallel with another class 2 power source. (Rule: 16-200(3))
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A device having a class 2 output shall be permitted for use as a device energy limiting characteristics. Rue ; 16-200(4))
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Transformers or other devices having class 2 outputs shall be protected on the supply side by an overcurrent device with a rating or setting not exceeding 20 A. ( Rule: 16-202(2))
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A class 2 power supply unit shall have permanent markings that are readily visible after installation to indicates: a) the class of supply and its electrical rating b) suitability for wet locations when intended for we locations. ( Rule: 16-204)
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over current shall not be an interchangeable type and it shall be an integral part of a transformer or other power supply device.(Rule: 16-208)
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overcurrent devices shall be located at the point where the insulated conductors to be protected receive their supply.(Rule: 16-208)
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The maximum allowable current shall be as listed in Table 57 for sizes No. 16 and smaller and current limitation should be exceed 5 A ( Rule: 16-210(4).
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Eight conductor cable for class 2 power and data communication circuits shall be permitted for use in accordance with Table 60. (Rule: 16-210(7)).
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Insulated conductors and cables of class 2 circuits shall be separated from insulated conductors of electric lighting and power ( Rule: 16-212 (1))
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Class 1 circuits operating at 300 V or less at least from insulated conductors of electric lighting and power
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Where electric lighting or power conductors are bare, all class 2 circuit insulted conductors and cables in the same room or space shall be enclosed in a metal raceway that is bonded to ground, and no opening such as an outlet box shall be permitted to be located within 2 of the bare conductors and including 15 kV or within 3 m of bare conductors above 15 kV.
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Direct buried class 2 circuits shall be:
- the class 2 circuit is in a metal-sheathed cable, with the sheath bonded to ground.
- the power circuit operate at 750 V or less
- all cables are insulated for the maximum voltage of any cable in the trench. ( Rule: 16-226)
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Cable bundle
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A class 2 power and data communication circuit shall be supplied from power sourcing equipment with an output limited to:
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Table 60 base on : a)the size of conductor b) the cable temperature rating c) the number of cables in a cable bundle in contact with each other d) the smallest conductor size and lowest temperature rating of any cable in the cable bundle.( Rule: 16-330(3)
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not more than 192 cables shall be permitted to be bundle together ( 16-330(3)(b))
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The correction factors of table 5A shall apply where class 2 power and data communication circuit cables are installed in an ambient temperature exceeding 30'C. ( Rule: 16-330(5)
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Where more than one cable bundle is installed in a ventilated and ladder-type cable tray, cable bundles shall be spaced at not less than :
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cables for class 2 power and data communication circuits shall not be required to comply with the cable bunding requirements where: a) the rating of each output circuit supplied by power sourcing equipment cannot exceed 0.3 A to any load conductor b) the cables have a minimum conductor size of 24 AWG. ( Rule: 16-330( 8) (a)(b)
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Class 1: less than 30 V and less than 1000 VA Class 2: less than 150 V and less than 100 VA( source: google)
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What is one of the major differences between class 1 and class 2 circuits?
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Class 2 circuit: low voltage and current, and therefore low power that it does not present a fire hazard or a shock hazard to personnel.(source: google)
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example of a class 2 circuit: low-energy voice, sound, intercom, or public address systems, low-voltage lighting, PLCs, security systems, or thermostats.
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Can you run class 1 and Class 2 wiring in the same conduit? Ans: Class 1 and Class 2 wiring are not permitted in the same enclosure, cable, or raceway.
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example of class 1 circuit: A class 1 circuit is the portion of wiring system between the load side of the overcurrent protection device (OPCD) or the power-limited supply and the connected load.
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What voltage are class 1 circuit conductors rated for?
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