SERVICE ENTRANCE EQUIPMENT INTRODUCTION TRANSFORMERS METERS SERVICE DISCONNECT OVERCURRENT PROTECTION PANELBOARDS SWITCHGEAR & SWITCHBOARDS UNIT SUBSTATIONS INTRODUCTION

SERVICE ENTRANCE EQUIPMENT INTRODUCTION TRANSFORMERS METERS SERVICE DISCONNECT OVERCURRENT PROTECTION PANELBOARDS SWITCHGEAR & SWITCHBOARDS UNIT SUBSTATIONS SERVICE ENTRANCE EQUIPMENT: TRANSFORMERS METERS MAIN DISCONNECT SWITCH PANELBOARDS & OVERCURRENT PROTECTION INTRODUCTION

SERVICE ENTRANCE EQUIPMENT TRANSFORMERS ELECTRICAL SUPPLY DESCRIPTION TYPES SIZE & RATING LOCATION CUSTOMER-OWNED METERS SERVICE DISCONNECT OVERCURRENT PROTECTION PANELBOARDS SWITCHGEAR & SWITCHBOARDS TRANSFORMERS

SERVICE ENTRANCE EQUIPMENT TRANSFORMERS ELECTRICAL SUPPLY DESCRIPTION TYPES SIZE & RATING LOCATION CUSTOMER-OWNED METERS SERVICE DISCONNECT OVERCURRENT PROTECTION PANELBOARDS SWITCHGEAR & SWITCHBOARDS DESCRIPTION: DEVICE WHICH CHANGES THE VOLTAGE OF AN A-C CIRCUIT TO A HIGHER OR LOWER VALUE. TRANSFORMERS

SERVICE ENTRANCE EQUIPMENT TRANSFORMERS ELECTRICAL SUPPLY DESCRIPTION TYPES SIZE & RATING LOCATION CUSTOMER-OWNED METERS SERVICE DISCONNECT OVERCURRENT PROTECTION PANELBOARDS SWITCHGEAR & SWITCHBOARDS CONSTRUCTION: AN IRON CORE ON WHICH TWO SEPARATE COILS ARE WOUND. THE COIL (WINDING) WITH THE GREATER NUMBER OF TURNS HAVING THE HIGHER VOLTAGE AND THE ONE WITH THE FEWER TURNS THE LOWER VOLTAGE. TRANSFORMERS

SERVICE ENTRANCE EQUIPMENT CONSTRUCTION: TYPES: STEP-UP: INCREASES VOLTAGE. STEP-DOWN: DECREASES VOLTAGE WINDINGS: PRIMARY: THE WINDING WHICH IS USED FOR INPUT TO A TRANSFORMER. SECONDARY: USED FOR OUTPUT. THE SECONDARY MAY BE DIVIDED INTO SEGMENTS, SO THAT THE OUTPUT VOLTAGE DEPENDS ON WHICH SEGMENTS ARE USED. TRANSFORMERS ELECTRICAL SUPPLY DESCRIPTION TYPES SIZE & RATING LOCATION CUSTOMER-OWNED METERS SERVICE DISCONNECT OVERCURRENT PROTECTION PANELBOARDS SWITCHGEAR & SWITCHBOARDS TRANSFORMERS

SERVICE ENTRANCE EQUIPMENT SINGLE-PHASE: TWO-WIRE SECONDARY: HAS ONE WIRE GROUNDED, WHICH THEN BECOMES THE NEUTRAL. THREE-WIRE SECONDARY: DIVIDED INTO TWO SEGMENTS. ONE LEAD IS AT THE END OF THE SECONDARY, A SECOND LEAD IS CONNECTED TO THE MIDPOINT OF THE SECONDARY & GROUNDED, & THE THIRD LEAD IS CONNECTED TO THE OTHER END OF THE SECONDARY. TRANSFORMERS ELECTRICAL SUPPLY DESCRIPTION TYPES SIZE & RATING LOCATION CUSTOMER-OWNED METERS SERVICE DISCONNECT OVERCURRENT PROTECTION PANELBOARDS SWITCHGEAR & SWITCHBOARDS TRANSFORMERS

SERVICE ENTRANCE EQUIPMENT TRANSFORMERS ELECTRICAL SUPPLY DESCRIPTION TYPES SIZE & RATING LOCATION CUSTOMER-OWNED METERS SERVICE DISCONNECT OVERCURRENT PROTECTION PANELBOARDS SWITCHGEAR & SWITCHBOARDS THREE-PHASE TRANSFORMERS

SERVICE ENTRANCE EQUIPMENT TRANSFORMERS ELECTRICAL SUPPLY DESCRIPTION TYPES SIZE & RATING LOCATION CUSTOMER-OWNED METERS SERVICE DISCONNECT OVERCURRENT PROTECTION PANELBOARDS SWITCHGEAR & SWITCHBOARDS TRANSFORMERS

SERVICE ENTRANCE EQUIPMENT OUTDOORS: ADVANTAGES: NO BUILDING SPACE REQUIRED. REDUCED NOISE PROBLEMS WITHIN THE BUILDING. LOWER COST. EASE OF MAINTENANCE & REPLACEMENT. NO INTERIOR HEAT GAIN PROBLEM. OPPORTUNITY TO USE LOW-COST, LONG-LIFE OIL FILLED UNITS. DISADVANTAGES: VANDALISM. DIRECT SUNLIGHT DECREASES OUTPUT BY INCREASING OPERATING TEMPERATURES. OBJECTIONABLE APPEARANCE. TRANSFORMERS ELECTRICAL SUPPLY DESCRIPTION TYPES SIZE & RATING LOCATION CUSTOMER-OWNED METERS SERVICE DISCONNECT OVERCURRENT PROTECTION PANELBOARDS SWITCHGEAR & SWITCHBOARDS TRANSFORMERS

SERVICE ENTRANCE EQUIPMENT TRANSFORMERS ELECTRICAL SUPPLY DESCRIPTION TYPES SIZE & RATING LOCATION CUSTOMER-OWNED METERS SERVICE DISCONNECT OVERCURRENT PROTECTION PANELBOARDS SWITCHGEAR & SWITCHBOARDS INDOORS: ADVANTAGES: GREATER SECURITY. EASIER TO CONCEAL (BASEMENT). DISADVANTAGES: HEAT GAIN (REQUIRING A FREE OPENING OF 3 SQ. IN. / KVA OR A LOUVER OF 8 SQ. IN / KVA) MAY REQUIRE A FIRE RATED ENCLOSURE (VAULT) TRANSFORMERS

SERVICE ENTRANCE EQUIPMENT TRANSFORMERS ELECTRICAL SUPPLY DESCRIPTION TYPES SIZE & RATING LOCATION CUSTOMER-OWNED METERS SERVICE DISCONNECT OVERCURRENT PROTECTION PANELBOARDS SWITCHGEAR & SWITCHBOARDS CUSTOMER-OWNED TRANSFORMERS: LARGE USERS: COST SAVINGS IN BUYING LARGER QUANTITIES OF POWER AT THE DISTRIBUTION VOLTAGE FOR REDUCED RATES MORE THAN COMPENSATES FOR THE COST OF MAINTAINING THEIR OWN TRANSFORMERS. SMALL USERS: SMALL SAVINGS WHICH NORMALLY DO NOT JUSTIFY HIGH INITIAL EXPENSE OF INSTALLING A TRANSFORMER. TRANSFORMERS

SERVICE ENTRANCE EQUIPMENT TRANSFORMERS ELECTRICAL SUPPLY DESCRIPTION TYPES SIZE & RATING LOCATION CUSTOMER-OWNED METERS SERVICE DISCONNECT OVERCURRENT PROTECTION PANELBOARDS SWITCHGEAR & SWITCHBOARDS CUT-OFF POINT FOR COST-EFFECTIVENESS: UTILITY RATES. TRANSFORMER COSTS. AMOUNT OF ELECTRICITY USED. TRANSFORMERS

SERVICE ENTRANCE EQUIPMENT INTRODUCTION TRANSFORMERS METERS DESCRIPTION LOCATION SERVICE DISCONNECT OVERCURRENT PROTECTION PANELBOARDS SWITCHGEAR & SWITCHBOARDS UNIT SUBSTATIONS DESCRIPTION: A DEVICE WHICH IS NORMALLY PROVIDED AT THE SERVICE ENTRANCE BY THE UTILITY COMPANY TO MEASURE HOW MUCH ELECTRICITY A FACILITY USES. THE METER IS THE PROPERTY OF THE UTILITY. METERS

SERVICE ENTRANCE EQUIPMENT INTRODUCTION TRANSFORMERS METERS DESCRIPTION LOCATION SERVICE DISCONNECT OVERCURRENT PROTECTION PANELBOARDS SWITCHGEAR & SWITCHBOARDS UNIT SUBSTATIONS LOCATION: ALWAYS INSERTED AHEAD OF THE MAIN SWITCH TO PREVENT THEM FROM BEING DISCONNECTED. CAN BE INSIDE OR OUTSIDE, BUT THE UTILITY PERSONNEL MUST HAVE ACCESS TO AN INSIDE METER. METERS

SERVICE ENTRANCE EQUIPMENT DESCRIPTION: MEANS OF DISCONNECTING AN ENTIRE BUILDING FROM THE ELECTRICAL SERVICE. IT MAY BE MORE THAN ONE SWITCH, BUT NO MORE THAN SIX. MAIN SWITCHES CONTROL ALL THE CIRCUITS IN THE BUILDING INTRODUCTION TRANSFORMERS METERS SERVICE DISCONNECT DESCRIPTION FUNCTION LOCATION OVERCURRENT PROTECTION PANELBOARDS SWITCHGEAR & SWITCHBOARDS UNIT SUBSTATIONS SERVICE DISCONNECT

SERVICE ENTRANCE EQUIPMENT INTRODUCTION TRANSFORMERS METERS SERVICE DISCONNECT DESCRIPTION FUNCTION LOCATION OVERCURRENT PROTECTION PANELBOARDS SWITCHGEAR & SWITCHBOARDS UNIT SUBSTATIONS FUNCTION: DE-ENERGIZES ALL ELECTRICAL EQUIPMENT & CIRCUITS DURING MAJOR REPAIRS. ALLOWS THE FIRE DEPARTMENT TO MAKE CERTAIN THAT THERE ARE NO LIVE WIRES INSIDE THE BUILDING. LOCATION: NEAR THE POINT OF SERVICE ENTRY INTO THE BUILDING. SERVICE DISCONNECT

SERVICE ENTRANCE EQUIPMENT DESCRIPTION: DEVICES DESIGNED TO DISCONNECT A CIRCUIT AUTOMATICALLY WHENEVER THE CURRENT REACHES A PREDETERMINED VALUE THAT WOULD CAUSE A DANGEROUSLY HIGH TEMPERATURE IN THE CONDUCTOR. HIGH TEMPERATURES CAN BE CAUSED BY SHORT CIRCUITS, EXCESSIVE DRAW OR A SURGE FROM THE UTILITY COMPANY. INTRODUCTION TRANSFORMERS METERS SERVICE DISCONNECT OVERCURRENT PROTECTION DESCRIPTION FUNCTION TYPES PANELBOARDS SWITCHGEAR & SWITCHBOARDS UNIT SUBSTATIONS OVERCURRENT PROTECTION

SERVICE ENTRANCE EQUIPMENT INTRODUCTION TRANSFORMERS METERS SERVICE DISCONNECT OVERCURRENT PROTECTION DESCRIPTION FUNCTION TYPES PANELBOARDS SWITCHGEAR & SWITCHBOARDS UNIT SUBSTATIONS FUNCTION: PREVENTS ELECTRICAL FIRES. PREVENTS POSSIBLE EXPLOSION. PREVENTS DAMAGE TO EXPENSIVE EQUIPMENT. OVERCURRENT PROTECTION

SERVICE ENTRANCE EQUIPMENT INTRODUCTION TRANSFORMERS METERS SERVICE DISCONNECT OVERCURRENT PROTECTION DESCRIPTION FUNCTION TYPES PANELBOARDS SWITCHGEAR & SWITCHBOARDS UNIT SUBSTATIONS FUSES: CONTAIN A SHORT STRIP OF METAL WITH A LOW MELTING POINT. WHEN INSTALLED IN ITS FUSE-HOLDER, IT BECOMES A LINK IN THE CIRCUIT. FUSES ARE ONE-TIME DEVICES. MORE RELIABLE THAN CIRCUIT BREAKERS. OVERCURRENT PROTECTION

SERVICE ENTRANCE EQUIPMENT INTRODUCTION TRANSFORMERS METERS SERVICE DISCONNECT OVERCURRENT PROTECTION DESCRIPTION FUNCTION TYPES PANELBOARDS SWITCHGEAR & SWITCHBOARDS UNIT SUBSTATIONS CIRCUIT BREAKERS: CONTAIN A SIMPLE MECHANISM THAT TRIPS OPEN A CIRCUIT IN RESPONSE TO AN OVERLOAD CONDITION. CONVENIENT: CAN BE RESET BY A MANUAL SWITCH TO RESTORE POWER. CAN SERVICE AS A SWITCH TO TURN A CIRCUIT ON OR OFF. MORE EXPENSIVE THAN FUSES TO INSTALL. OVERCURRENT PROTECTION

SERVICE ENTRANCE EQUIPMENT INTRODUCTION TRANSFORMERS METERS SERVICE DISCONNECT OVERCURRENT PROTECTION PANELBOARDS DESCRIPTION & FUNCTION LABELING SWITCHGEAR & SWITCHBOARDS UNIT SUBSTATIONS DESCRIPTION: THE BOX IN WHICH THE CIRCUIT PROTECTIVE DEVICES ARE GROUPED & FEED, ALONG WITH THE SERVICE DISCONNECT SWITCHES & SWITCHES TO MAJOR BRANCH LINES. FUNCTION: PANELBOARDS ACCEPT A RELATIVELY LARGE BLOCK OF POWER & DISTRIBUTE IT IN SMALLER BLOCKS. PANELBOARDS

SERVICE ENTRANCE EQUIPMENT INTRODUCTION TRANSFORMERS METERS SERVICE DISCONNECT OVERCURRENT PROTECTION PANELBOARDS DESCRIPTION & FUNCTION LABELING SWITCHGEAR & SWITCHBOARDS UNIT SUBSTATIONS LABELING: LP: LIGHTING PANEL KP: KITCHEN PANEL AHU: AIR HANDLING UNIT. AC: AIR CONDITIONING PANELBOARDS

SERVICE ENTRANCE EQUIPMENT SWITCHBOARDS: LARGE BUILDING OFTEN HAVE THEIR MAIN (PRIMARY) SWITCHES TOGETHER WITH THEIR SECONDARY (FEEDER) SWITCHES, & CIRCUIT PROTECTION DEVICES ALL ENCASED IN A FREESTANDING ASSEMBLY CALLED A SWITCHBOARD. SWITCHGEAR: SUCH A PACKAGE DESIGNED FOR HIGH-VOLTAGE (ABOVE 600-V) SWITCHING EQUIPMENT IN MULTIPLE UNITS, NOT CONSOLIDATED IN A SINGLE UNIT. INTRODUCTION TRANSFORMERS METERS SERVICE DISCONNECT OVERCURRENT PROTECTION PANELBOARDS SWITCHGEAR & SWITCHBOARDS DESCRIPTION LOCATION & SPACE REQUIREMENTS UNIT SUBSTATIONS SWITCHGEAR & SWITCHBOARDS

SERVICE ENTRANCE EQUIPMENT INTRODUCTION TRANSFORMERS METERS SERVICE DISCONNECT OVERCURRENT PROTECTION PANELBOARDS SWITCHGEAR & SWITCHBOARDS DESCRIPTION LOCATION & SPACE REQUIREMENTS UNIT SUBSTATIONS LOCATION: GENERALLY IN THE BASEMENT WITHIN A SEPARATE, WELL-VENTILATED ROOM DESIGNED FOR THAT PURPOSE. SPACE REQUIREMENTS: EXACT SPACE REQUIREMENTS ARE OBTAINED FROM THE ELECTRICAL CONSULTANT. SWITCHGEAR & SWITCHBOARDS

SERVICE ENTRANCE EQUIPMENT INTRODUCTION TRANSFORMERS METERS SERVICE DISCONNECT OVERCURRENT PROTECTION PANELBOARDS SWITCHGEAR & SWITCHBOARDS UNIT SUBSTATIONS DESCRIPTION: A SINGLE PACKAGE COMBINING A STEP-DOWN TRANSFORMER WITH A COMPLETE SWITCHBOARD AND METERS. ALSO CALLED A LOAD-CENTER SUBSTATION. UNIT SUBSTATION