Electrical Symbols and Outlets OBJECTIVES After studying this unit, the student will able to . identify and explain the electrical outlet symbols used in the plans of the single-family dwelling. discuss the types of outlets, boxes, fixtures, and switches used in the residence. explain the methods of mounting the various electrical devices used in the residence. understand the meaning of the terms receptacle outlet and lighting outlet. understand the preferred way to position receptacles in wall boxes. position wall boxes in relation to finished wall surfaces. make surface extensions from concealed wiring. determine the number of wires permitted in a given size box. ELECTRICALSYMBOLS In Fig. 2-1 the outletsare shownby the symbols Electrical symbols used on an architectural plan §= and --9-. The standard electrical symbols are show the location and type of electrical device re- shown in Fig. 2-4 to Fig. 2-10 (pages 14-18). quired. A typical electrical installation as taken from a plan is shown in Fig. 2-1. The c.E.c., PartI definesan outletas a point on 53 a wiring system where current is taken to supply /' G ,.. utilization equipment. I A receptacle outlet is an outlet where one or I more receptacles are installed (Fig. 2-2). \1. 53 A lightingoutletis "an outletintendedfor the di- ~_~I rect connection of a lampholder, a lighting fixture, or a pendantcord terminatingin a lampholder"(Fig. 2-3). A toggle switch is not an outlet, however, the term outlet is used broadly by electricians to in- clude noncurrent-consuming switches and similar control devices in a wiring system when estimat- ing the cost of the installation. Each type of outlet Fig.2-1 Use of electrical symbols and notations on a is represented on the plans as a symbol. floor plan. 12 Unit 2 Electrical Symbols and Outlets 13 ALWAYS ALLOW AT LEAST 150 mm (6 in) OF FREECONDUCTOR AT ALL OUTLETS AND JUNCTIONS SO AS TO BE ABLE TO WORK EASILY WITH THE WIRING DEVICESTO BE INSTALLED. Fig. 2-2 When a receptacle is connected to the wires, the outlet is called a receptacleoutlet. For ease in working with wiring devices, the C.E.C, Part I in Rule 12-3002(4) requires that at least 150 mm (6 in) of free conductor be provided. dwelling shows that many different electrical sym- bols are used to represent the electrical devices and equipment used in the building. In drawing electrical plans, most architects, designers, and electrical engineers use symbols approved by the American National Standards Institute (ANSI)whereverpossible.However,plans may contain symbols that are not found in these standards. When such unlisted (nonstandard) sym- bols are used, the electrician must refer to a legend that interprets these symbols. The legend may be included on the plans or in the specifications. In Fig. 2-3 When a lighting fIXtureis connected to the wires, many instances, a notation on the plan will clarify the outlet is called a lighting outlet. The C.E.C, Part I re- the meaning of the symbol. quires that at least 150 mm (6 in) of free conductor be Figs. 2-4 through 2-10 (pages 14-18) list the provided. standard, approved electrical symbols and their meanings. Many of these symbols can be found on The dash lines in Fig. 2-1 run from the outletto the accompanying plans of the residence. Note in the switch or switchesthat controlthe outlet. These these figures that several symbols have the same lines are usually curved so that they cannot be mis- shape. However,differences in the interior presen- taken for invisibleedge lines. Outlets shown on the tation indicate that the meaningsof the symbols are plan without curveddash lines are independentand different. For example, different meanings are have no switch control. shown in Fig. 2-10 (page 18) for the outlet sym- A study of the plans for the single-family bols. A good practice to follow in studying sym- 14 Unit 2 Electrical Symbols and Outlets OUTLETS CEILING WALL INCANDESCENT 0 -Q- a -0 -Q- -a LAMPHOLDER W/PULL SWITCH OPS @ -OPS -<ID RECESSED r-, r-, INCANDESCENT [Q] L_.JI-Q-I @ -tQj -@ SURFACE FLUORESCENT I 0 I -CQ RECESSED FLUORESCENT IOR I --[QR SURFACE OR PENDANT CONTINUOUS ROW [Q FLUORESCENT RECESSED CONTINUOUS ROW IOR FLUORESCENT BARE LAMP FLUORESCENT STRIP SURFACE OR PENDANT EXIT <9 -0 RECESSED CEILING EXIT @ -@ BLANKED OUTLET @ -@ OUTLET CONTROLLED BY LOW-VOLTAGE SWITCHING WHEN RELAY IS INSTALLED (0 --(0 IN OUTLETBOX JUNCTION BOX 0 -0 Fig.2-4 Lighting outlet symbols. Unit 2 Electrical Symbols and Outlets 15 RECEPTACLE OUTLETS -e SINGLE RECEPTACLE OUTLET =@ DUPLEX RECEPTACLE OUTLET =@IG INSULATED (ISOLATED) GROUND RECEPTACLE OUTLET =@ TRIPLEX RECEPTACLE OUTLET ~ DUPLEX RECEPTACLEOUTLET, SPLIT-SWITCHED CIRCUIT =@ DUPLEX RECEPTACLEOUTLET, SPLIT-WIRED CIRCUIT (THREE-WIRE) =@WP WEATHERPROOFRECEPTACLEOUTLET GROUND-FAULT CIRCUIT INTERRUPTER =@GrCI RECEPTACLE OUTLET SPECIAL-PURPOSEOUTLET (SUBSCRIPT LETTERS @cw INDICATE SPECIAL VARIATIONS: DW -DISHWASHER. ALSO a, b, C,d, ETC.ARE LETTERSKEYEDTO EXPLANATION ON DRAWINGS OR IN SPECIFICATIONS). =@R RANGE OUTLET =@c CLOTHES DRYER OUTLET ([) FAN OUTLET @ CLOCK OUTLET 0 FLOOR OUTLET MULTIOUTLET ASSEMBLY; ARROW SHOWS LIMIT OF INSTALLATION. APPROPRIATE SYMBOL INDICATES 1YPE OF OUTLET. SPACING OF OUTLETS INDICATED ~ BY "X"" INCHES. ~ FLOOR SINGLE RECEPTACLE OUTLET ~ FLOOR DUPLEX RECEPTACLE OUTLET ~ FLOOR SPECIAL-PURPOSE OUTLET Fig. 2-5 Receptacle outlet symbols. 16 Unit 2 Electrical Symbols and Outlets CIRCUITING SWITCH OUTLETS 1 2 ........ BRANCH-CIRCUIT HOME RUN TO PANEL S SINGLE-POLE SWITCH THREE WIRES IN CABLE OR RACEWAY S2 DOUBLE-POLE SWITCH IIf S3 THREE-WAY SWITCH -l1li- FOUR WIRES IN CABLE OR RACEWAY, ETC. S4 FOUR-WAY SWITCH DOOR SWITCH SOME DRAWINGSUSE THIS METHOD SD /If OF CONDUCTORIDENTIFICATION: SDS DIMMER SWITCH EQUIPMENTGROUNDINGCONDUCTOR: LONG LINE WITH DOT. SK KEY SWITCH NEUTRALCONDUCTOR:LONG LINE. LOW-VOLTAGE SWITCH PHASE CONDUCTORWITH SWITCH LEGS: SL SHORT LINE. SLM LOW-VOLTAGE MASTER SWITCH WIRING CONCEALEDIN CEILING OR Sp SWITCH WITH PILOT LAMP WALL VARIABLE-SPEED SWITCH sF --- WIRING CONCEALEDIN FLOOR TIME SWITCH ST ----- WIRING EXPOSED SWP WEATHERPROOF SWITCH 0 WIRINGTURNED UP . WIRINGTURNED DOWN Fig. 2-6 Switch outlet symbols. CONDUITONLY (EMPTY) CO bols is to learn the basic forms first and then add --- SWITCH LEG INDICATION.CONNECTS the supplemental information to obtain different OUTLETSWITH CONTROLPOINTS. meamngs. AN ARROWINDICATESA BRANCH-CIRCUIT HOME RUN TO PANEL. THE NUMBER OF ARROWSINDICATESTHE NUMBER FIXTURES AND OUTLETS OF CIRCUITS. IF THERE ARE NO CROSSHATCHES,THEN IT IS Architects often include in the specificationsa cer- ASSUMEDTHAT THE RACEWAYCONTAINSTWO WIRES. tain amount of money for the purchase of electrical fixtures.Theelectricalcontractorincludesthisamount Fig. 2-7 Circuiting symbols. in the bid, and the choice of fixtures is then left to the homeowner.If the owner selects fixtures whose total costexceedsthe fixtureallowance,the owneris ufactured wiring systems where the "box" is an in- tegral part of the system. For standard wiring meth- expected to pay the difference between the actual cost ods, such as cable or conduit, a box is usually andthe specificationallowance.If the fixturesare not required. selectedbeforethe roughing-instageof wiringof the Outlet boxes must be accessible, Rule house, the electrician usually installs outlet boxes 12-3016(1). having standardfixturemountingstuds. Be careful when roughing in boxes for fixtures Most modern surface-mount lighting fixtures and also when hanging ceiling fixtures to: can be fastened to an octagon box (Fig. 2-11 (page 19), top row) or an outlet box with a plaster ring . nonmetallic device (switch) boxes. using appropriate No. 8-32 metal screws and . nonmetallic device (switch) plaster rings. mountingstrapfurnishedwith the fixture(Fig.2-11, metallic device (switch) boxes. third row). A box must be installed at each outlet or switch . metallic device (switch) plaster rings. location,Rule 12-3002(1). There are exceptions to . any nonmetallic box, unless specifically this rule, but in general they relate to special man- marked on the box or carton for use as a fixture Unit 2 Electrical Symbols and Outlets 17 G PUSH BUTTON 111111- BATTERY D' BUZZER -1111 GROUND [J!) BELL 0 JUNCTION BOX - CEILING JUNCTION BOX - WALL \[]!) COMBINATION BELL/BUZZER -0 ~ EJ CHIME - - CIRCUIT BREAKER OVERCURRENT DEVICE (FUSE, 0- ANNUNCIATlOR ~ BREAKER, THERMAL OVERLOAD) 0 ELECTRIC DOOR OPENER - '-(D}- SWITCH AND FUSE 0 MAID'S SIGNAL PLUG OR SWITCH AND FUSE I<J TELEPHONE (PRIVATE SYSTEM) -~ ~ TELEPHONE (OUTSIDE LINE) THERMOSTAT <D CEILING PADDLE FAN [2] TRANSFORMER X ~ TELEVISION OUTLET - LIGHTING PANEL CEILING PADDLE FAN W/LlGHT r1J'JZi.IPOWER PANEL w. HEATING PANEL X Fig. 2-8 Miscellaneous symbols. support, or to support other equipment, or to framing, recessing, or mounting requirements for accommodateheat-producingequipment. the fixtures. This information must be provided in the case of recessed fixtures, which require a spe- Therefore,unless the box, deviceplasterring, or cific wall or ceiling opening. carton is markedto indicatethat it has been listedby Many types of lighting fixtures are presently CSA for the support of fixtures, do not use where available.Fig. 2-11 (page 19)shows severaltypical fixtures are to be hung. Refer to Fig. 2-12 (page lighting fixtures that may be found in a dwelling 20) and Rule 12-1110. unit. Also shown are the electrical symbols used Be careful when installing a ceiling outlet box on plans to designate these fixtures and the type of for the purpose of supporting a fan. See Unit 9 for outlet boxes or switch boxes on which the lighting detailed discussion of paddle fans and their instal- fixturescan be mounted. A standard receptacleout- lation. let is shown as well. The switch boxes shown with If the owner selects fixtures prior to construc- it are made of steel.Switchboxes may also be made tion, the architect can specify these fixtures in the of plastic, as shown in Fig. 2-12 (page 20). Other plans and/or specifications.