BIRD ISLAND FLATS SUBSTATION (BUILDING 67) ONE LINE DIAGRAM SET# 23 LEGEND DRAW-OUT CIRCUIT BREAKER DRAW-OUT CIRCUIT BREAKER, DRAW-OUT FUSES DRAW-OUT FUSES AND POTENTIAL TRANSFORMERS CABLE CONNECTION POTENTIAL TRANSFORMER CURRENT TRANSFORMER VOLTAGE TRANSFORMER NORMALLY OPEN BUILDING NUMBER SUBSTATION & ASSOCIATED FEEDER COLOR CODES WOOD ISLAND SUB. 486 HARBORSIDE SUBSTATION INTERTIE (15A1-7) WOOD ISLAND SUBSTATION [2] INTERTIE (15W1-13) HARBORSIDE SUBSTATION INTERTIE (15A2-7) 15AE1-3 PORTER STREET SUB. 308 BIRD ISLAND FLATS SUB. 592 HARBORSIDE SUB. 152 UTILITY FEEDER (#592-70H) (#592-72X & Y) WARNING! This one line diagram has been prepared based on the latest available information from as-built drawings and visual field survey, updated and revised as marked. The accuracy and completeness of the information are not guaranteed or represented as correct. Actual field verification is required and all safety measures must be taken prior to operations and/or maintenance work. Only authorized personnel are allowed access to this equipment. This plan is intended for informational purposes only and no use shall be made of the same without the express written permission of the Massachusetts Port Authority ("Massport"). REVISION DATE: 12/23/16 MASSACHUSETTS PORT AUTHORITY LOGAN INTERNATIONAL AIRPORT EAST BOSTON, MA CAPITAL PROGRAMS DEPARTMENT ELECTRICAL DISTRIBUTION SYSTEM ONE LINE DIAGRAMS BIRD ISLAND FLATS SUBSTATION (BUILDING 67) 4 105 S1L-02

WOOD ISLAND SUBSTATION (486) ONE LINE DIAGRAM SET# 23 LEGEND DRAW-OUT CIRCUIT BREAKER DRAW-OUT CIRCUIT BREAKER, DRAW-OUT FUSES B.I.F. SUBSTATION [67] INTERTIE (15B1-8) DRAW-OUT FUSES AND POTENTIAL TRANSFORMERS POTENTIAL TRANSFORMER PORTER ST. SUBSTATION [41] INTERTIE #1 (15P1-7) CURRENT TRANSFORMER VOLTAGE TRANSFORMER NORMALLY OPEN BUILDING NUMBER PREFERRED FEEDER SUBSTATION & ASSOCIATED FEEDER COLOR CODES WOOD ISLAND SUB. 486 PORTER STREET SUB. 308 BIRD ISLAND FLATS SUB. 592 (#486-199H) 15AE1-3 HARBORSIDE SUB. 152 UTILITY FEEDER (#486-198) WARNING! This one line diagram has been prepared based on the latest available information from as-built drawings and visual field survey, updated and revised as marked. The accuracy and completeness of the information are not guaranteed or represented as correct. Actual field verification is required and all safety measures must be taken prior to operations and/or maintenance work. Only authorized personnel are allowed access to this equipment. This plan is intended for informational purposes only and no use shall be made of the same without the express written permission of the Massachusetts Port Authority ("Massport"). REVISION DATE: 12/23/16 MASSACHUSETTS PORT AUTHORITY LOGAN INTERNATIONAL AIRPORT EAST BOSTON, MA PORTER ST. SUBSTATION [41] INTERTIE #2 (15P2-6) CAPITAL PROGRAMS DEPARTMENT ELECTRICAL DISTRIBUTION SYSTEM ONE LINE DIAGRAMS WOOD ISLAND SUBSTATION (486) 5 105 S1L-03

PORTER STREET SUBSTATION (308) ONE LINE DIAGRAM SET# 23 LEGEND DRAW-OUT CIRCUIT BREAKER DRAW-OUT CIRCUIT BREAKER, DRAW-OUT FUSES DRAW-OUT FUSES AND POTENTIAL TRANSFORMERS POTENTIAL TRANSFORMER UTILITY INCOMING (#308-197) UTILITY INCOMING (#308-54) CURRENT TRANSFORMER VOLTAGE TRANSFORMER NORMALLY OPEN BUILDING NUMBER PREFERRED FEEDER SUBSTATION & ASSOCIATED FEEDER COLOR CODES WOOD ISLAND SUB. 486 PORTER STREET SUB. 308 BIRD ISLAND FLATS SUB. 592 HARBORSIDE SUB. 152 WOOD ISLAND SUBSTATION [2] INTERTIE (15W2-8) 15AE1-3 UTILITY FEEDER WOOD ISLAND SUBSTATION [2] INTERTIE (15W1-2) HARBORSIDE SUBSTATION INTERTIE (15A2-2) HARBORSIDE SUBSTATION INTERTIE (15A1-2) WARNING! This one line diagram has been prepared based on the latest available information from as-built drawings and visual field survey, updated and revised as marked. The accuracy and completeness of the information are not guaranteed or represented as correct. Actual field verification is required and all safety measures must be taken prior to operations and/or maintenance work. Only authorized personnel are allowed access to this equipment. This plan is intended for informational purposes only and no use shall be made of the same without the express written permission of the Massachusetts Port Authority ("Massport"). REVISION DATE: 12/23/16 MASSACHUSETTS PORT AUTHORITY LOGAN INTERNATIONAL AIRPORT EAST BOSTON, MA CAPITAL PROGRAMS DEPARTMENT ELECTRICAL DISTRIBUTION SYSTEM ONE LINE DIAGRAMS PORTER STREET SUBSTATION (308) 6 105 S1L-04

HARBORSIDE SUBSTATION (152) ONE LINE DIAGRAM SET# 23 LEGEND DRAW-OUT CIRCUIT BREAKER DRAW-OUT CIRCUIT BREAKER, DRAW-OUT FUSES DRAW-OUT FUSES AND POTENTIAL TRANSFORMERS POTENTIAL TRANSFORMER CONTROL POTENTIAL TRANSFORMER VOLTAGE TRANSFORMER NORMALLY OPEN (#152-53H) (#152-87H) SUBSTATION & ASSOCIATED FEEDER COLOR CODES WOOD ISLAND SUB. 486 PORTER STREET SUB. 308 BIRD ISLAND FLATS SUB. 592 HARBORSIDE SUB. 152 UTILITY FEEDER 15AE1-3 BIF SUBSTATION INTERTIE (15B2-8) PORTER ST. SUBSTATION INTERTIE (15P2-12) PORTER ST. SUBSTATION INTERTIE (15P1-12) BIF SUBSTATION INTERTIE #1 (15B1-14) WARNING! This one line diagram has been prepared based on the latest available information from as-built drawings and visual field survey, updated and revised as marked. The accuracy and completeness of the information are not guaranteed or represented as correct. Actual field verification is required and all safety measures must be taken prior to operations and/or maintenance work. Only authorized personnel are allowed access to this equipment. This plan is intended for informational purposes only and no use shall be made of the same without the express written permission of the Massachusetts Port Authority ("Massport"). REVISION DATE: 10/14/15 MASSACHUSETTS PORT AUTHORITY LOGAN INTERNATIONAL AIRPORT EAST BOSTON, MA CAPITAL PROGRAMS DEPARTMENT ELECTRICAL DISTRIBUTION SYSTEM ONE LINE DIAGRAMS HARBORSIDE SUBSTATION (152) 7 105 S1L-05