N New Standard

R Redrawn Standard C Changed Standard ~ No Change

1400

UNDERGROUND TRANSFORMERS

7/10/2020

C F1A Bay-O-Net Fuse Schedule for Padmount Transformers

~ HB16,HB32 Hillside Barrier

~ UID1 Padmounted Equipment Identification Tags & Safety

Signs

~ UT2 1Ø Padmount Transformer Radial Feed

~ UT4 Open Y - Open Δ Padmount Transformer Installation

~ UT21, UT22 1Ø Padmount Transformer Assemblies, Loop Feed

~ UT24-UT28 1Ø Padmount Transformer Assembly, Radial or Loop

w/ Feed-Thru Bushing

~ UT30-UT32 3Ø Padmount Transformer Assemblies

~ UTB 1Ø Padmount Transformer Boxpad (Basement)

~ UTP1 Transformer Pad, 1Ø, 25 to 75kVA

~ UTP2A Transformer Pad, 1Ø, 100kVA

~ UTP3 1Ø Transformer Pad Orientation & Conduit Installation

(100 kVA)

~ UTP4 Transformer Pad, 3Ø, 75 to 1500kVA

~ UTP4-6 Precast Pad & Vault for 3Ø Transformers

~ UTP6 (p. 1) 3Ø Transformer Pad Orientation & Conduit Installation

~ UTP6 (p. 2) 1Ø Transformer Pad Orientation & Conduit Installation

(25-75 kVA)

~ UTP9 Typical Barrier Installation to Protect Padmounted

Equipment

~ N/A Clearances (from Commercial Handbook)

DATE

SECTION

APP:

R

CONSTRUCTION STANDARDS

DATE:

ENGR

REVISIONS

OPS

CAD FILE:PAGE:

of

F1AF1A11

ELM

1/31/80

1400

FUSE SCHEDULE

PADMOUNT TRANSFORMERS

1 3/02 DRAWN IN CAD

2 2/11/10 KJP

3 7/10/20 KJP

kVA

Transformer

Stock Number

Transformer

Primary Protection

Minimum

Upstream OH

Fuse Size

*2

BM

240/120

BR

480/120Bayonet Fuse No

S/N

Isolation Link Size

S/N

25

*1

1317

4000358C05 (8 A)

653 3001861A02 25 A 683

50 1318 2016

4000358C08 (15 A)

654 3001861A03 30 A 684

75 1320

4000358C10 (25 A)

655 3001861A05 65 A 687

100 1322

4000358C10 (25 A)

655 3001861A05 65 A 687

1ø Padmounted Transformers

Notes:

*1 Fuses for 25 kVA livefront transformers are stocked for maintenance only (RTE 476B1, S/N 1664).

*2 Use largest fuse size for applications while considering up/downstream fuses, conductor, and loading. Check with

Systems Engineering as needed.

*3 Recommended fuse will result in some loss of overload capability.

*4 Transformer and upstream protection may miscoordinate, therefore each transformer should ideally be on separate

feeders/protection.

*5 Fuse will limit overload capability of transformer.

*6 The use of these fuses will provide 175% of rated load for 2 hours and 150% of rated load for 7 hours.

Rev. 3 - Added 2000 & 2500 kVA, stock numbers, upstream fuses and notes.

Spare fuses are kept in each transformer. It is the responsibility of the person using the spare

fuse to replace it. Fuses are in free issue.

kVA

Transformer

Stock Number

Transformer

Primary Protection

Minimum

Upstream OH

Fuse

*2

BL

208/120

BW

480/277Bayonet Fuse No

S/N

Isolation Link Size

S/N

75 1328 1337

4000358C05 (8 A)

653 3001861A02 25 A 683

150 1329 1338

4000358C08 (15 A)

654 3001861A03 30 A 684

300 1331 1340

4000358C10 (25 A)

655 3001861A05 50 A 686

500 1332 1341

4000358C12 (50 A)

656 3001861A06 100 A 689

750 1333 1342

4000358C12 (50 A)

656 3001861A06 100 A 689

1000 1334 1343

4000358C14 (65 A)

*3

657 3001861A07 100 A

*4

689

1500 1344

4000353C17 (140 A)

658 3001861A05 100 A

*4*5

689

ELSP Fuse

*6

2000 2164

4038361C05C (125 A)

2976 CBUC08250D100

See Systems

Engineering

2500 1345

4038361C05C (125 A)

2976 CBUC08250D100

3ø Padmounted Transformers

PLAN VIEW

SIDE VIEW

1 BARRIER, 16" Height

DESCRIPTIONQTY. S/N

SECONDARY PEDESTAL

EDGE OFTRANSFORMER

FRONT

SECONDARYPEDESTAL

PAD

TRANSFORMERFRONT

2 BARRIER, 32" Height 24611

1'-0" 3'-0"

Grade minimum 4"

21

1'-0"

3'-0"

REV 2: Corrected Measurement Behind Pad, and changed title from HB1 to HB16,HB32.

16"or32"

FRONT

below barrier

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of HB16,HB32 HB161 1 1400

HILLSIDE BARRIER1 4/26/04 LB AH2 5/30/07 LB AH

1 2460

QTY. S/NHB16 HB32ITEM

NO.

Label for outside of padmounted equipment S/N 2568

Label for inside of padmounted equipment S/N 2569

REV 1: ADDED ANSI SAFETY SIGNS

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UID1 UID11 3ELM

1/31/80 1400

PADMOUNTED EQUIPMENTIDENTIFICATION TAGS AND

SAFETY SIGNS0 REDRAWN IN CAD

0 6/13/021 6/23/04 LB AH

25T

COMBO

3

VIEW WITH LID CLOSEDVIEW WITH LID OPEN

KVA

1. SINGLE-PHASE PADMOUNTED TRANSFORMERS

2. THREE-PHASE PADMOUNTED TRANSFORMERS

VIEW WITH DOOR OPEN

PRIMARY

SECONDARY

3. OTHER PADMOUNT EQUIPMENT

VIEW WITH DOOR CLOSED

COMBO

SECONDARYCOMPARTMENT

75

120/208

#5078

PRIMARYCOMPARTMENT

TCL

LC

VIEW WITH DOOR OPEN VIEW WITH DOOR CLOSED

COMBO

COMBO

DANGER

DANGER

DANGER

DANGER

S/N 2569

S/N 2569

S/N 2568

CO. NUMBER &SEC. VOLTAGEIN 1-1/2" BLACKLETTERS

I.E.; 75 FOR 75KVA

A. TRANSFORMER RATINGIN 1-1/2" YELLOW LETTERS

I.E.; 75-TTRANSFORMER HAS TAPS

B. ADD SUFFIX "T" WHEN

S/N 2569

S/N 2569

S/N 2568

DANGER

S/N 2569

#1234

REV 1: ADDED ANSI SAFETY SIGNS

S/N 2568

3 BUSHING

TAPS

(IF APPLICABLE)

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UID1 UID12 3ELM

1/31/80 1400

PADMOUNTED EQUIPMENTIDENTIFICATION TAGS AND

SAFETY SIGNS0 REDRAWN IN CAD

0 6/13/021 6/23/04 LB AH

4. SINGLE-PHASE J-BOX

J 2345

COMBO

DANGER

S/N 2568

S/N 2569

4. THREE-PHASE J-BOX

B

LC

CL

C

A

J 2345

COMBO

S/N 2568

DANGER

S/N 2569

REV 1: ADDED ANSI SAFETY SIGNS

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UID1 UID13 3ELM

1/31/80 1400

PADMOUNTED EQUIPMENTIDENTIFICATION TAGS AND

SAFETY SIGNS0 REDRAWN IN CAD

0 6/13/021 6/23/04 LB AH

RADIAL FEED UT2

FRONT VIEW OF TRANSFORMER

* * - GROUNDING LUG

SEE US6 FOR SECONDARY CONNECTIONS DETAILS

OUTIN

4" ABOVE CURBOR FINAL GRADE

A

2"3"

Ground Lug8

Clamp, Ground Rod 5/8", SmallCap, Protective Insulated, 200AElbow, Loadbreak, 1/0, 200A, 175 mil

Rod, Ground 5/8" x 8'Conductor, Wire BSDC #4 SLD

Pad, Transformer 42" x 42"

567

4

1

Connector, Crimpet, #4 to #2

DESCRIPTION

1 842

2811

11

1376454929

1124

11

QTY.

2651312

S/N

9

32

1

2

3

4

5

6 78

MATERIAL LIST

Cover, Connector U.G.

Bolt, Machine, 1/2" x 1-1/2" SSElbow, Sealing Kit, 1/0, 175 & 220 mil

Connector, z-bar #2-500 MCM + StreetlightWasher, 2" x 3" x 3/16" w/ 9/16" Slotted Hole11

1312

10 1

332

22391

226622651415

131

TG

1312

9 11

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UT2 UT21 1JEH

2/22/00 1400

SINGLE PHASEPADMOUNT TRANSFORMER

RADIAL FEED

1 2/23/00 HWH MA2 9/23/04 LB AH3 12/29/04 LB AH4 11/11/16 KJP

LEAVE SLACK IN CONCENTRICNEUTRALS FOR FUTUREOPERATION. ADD #2 BCSD IFNECESSARY.

THIS DRAWING IS TYPICAL. USEONLY THE COMPONENTS REQUIREDIN THE MATERIAL LISTS.

NOTE: INSTALL GROUNDING LUG TO TANK

Rev. 4 - Corrected material issue.

10

6

ITEMNO.

OPEN DOOR OPEN DOOR

8 9

REMOVE GROUND STRAP(SEE NOTE 1)

X3

X1

X2

3

2

GROUND

H 1 B

H 1 A

X3

X1

X2

GRD.LUG

A 1H

1H B

1

7

10

GRD.LUG

56

6

OPENY

BANK

OPENY

BANK

**

4

5 53" 2" 3" 2"

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UT4 UT41 2 9/94 1400

OPEN WYE - OPEN DELTAPADMOUNT TRANSFORMER

INSTALLATION

2 9/23/2004 LB AH3 12/29/04 LB AH4 12/14/09 KJP5 2/4/2014 CM AH

Notes:

1. Remove ground strap from one secondary neutral bushing. Caution: Measure resistance from busing to tank. There may be an internal ground.2. Ground rods may be driven in trench.3. Primary and secondary cables may be arranged as required to fit job site.4. For 2-25kVA only. For other sizes refer to Clark Public Utilities Standards Engineer.5. See UTP1 for pad specifications.6. Both phases must come from the same source and direction.7. Put tags on cables that say "Open Y Bank".8. Maximum motor size shall be 15 horsepower.

LIGHTER POWER

Rev 5: Added second ground lug to power pots and "Open Bank" label.

*

TORQUE TO 20 FT-LBS. MAX.

A C B D

H1A H1B X3 X1 X2

BAY-O-NET FUSE BAY-O-NET FUSE

X2X1X31BHH1A

DBCA

AB

CN

REMOVE GROUND STRAP(SEE NOTE 1)

WIRING DIAGRAM

56

4

23

Rod, Ground, 5/8" x 8'

Lug, Grounding, #8 Sol-2/0 STRConnector, Crimpet #2 to #4 (2C4)Conductor, #4 Solid, BSDC 1/CClamp, Ground Rod 5/8", Small

1

DESCRIPTION

Elbow, Loadbreak, 1/0, 200A, 175 mil, Test Point

23

30 Ft.454842

376

22

1124281

QTY.2

S/N1312

910

87

Cap, Insulated, 200A

Conductor, Al, 4/0, 600V, U.G., 1/C

Cover, Z-Bar Connector, #6-500Connector, Z-Bar #6-500 5/8" Stud, Al/Cu

52

52266265

2265353

UT4

13 Ft.

Rev 5: Added second ground lug to power pots and "Open Bank" label.

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UT4 UT42 2 9/94 1400

OPEN WYE - OPEN DELTAPADMOUNT TRANSFORMER

INSTALLATION

2 9/23/2004 LB AH3 12/29/04 LB AH4 12/14/09 KJP5 2/4/2014 CM AH

2 278111 Label, "Open Bank"

1234

T

KVA

1235

T

KVA

11

ITEMNO.

FRONT VIEW OF TRANSFORMER

*

THIS DRAWING IS TYPICAL. USE

TO TANKNOTE: INSTALL GROUNDING LUG

- GROUNDING LUG

IN THE MATERIAL LISTS.ONLY THE COMPONENTS REQUIRED

*

NECESSARY.OPERATION. ADD #2 BSDC IFNEUTRALS FOR FUTURELEAVE SLACK IN CONCENTRIC

SEE US6 FOR SECONDARY CONNECTIONS DETAILS

(UT22 SHOWN)

OUTIN

1

2

8

7

1011

6

512 13

TAG

TAG TAG

TAG

TAG

16

3

7

10

14 15

3" 2"

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UT21-UT22 UT21-UT221 2 10/98 1400

SINGLE PHASEPADMOUNT TRANSFORMER ASSEMBLIES

LOOP FEED

0 2/22/00 HWH MA1 9/23/04 LB AH2 12/29/04 LB AH3 4/29/09 CM AH

F

Rev 3: Changed to Voltage-reset fault indicator.

N.O. LOOP FEED UT21FUTURE

LOOP FEED UT22

FAULT INDICATOR NORMALLY OPEN

DESCRIPTIONS/N

UT22QTY.

Bolt, Unistrut, Padmount Tie Down

Pad, Transformer 42" x 42"

1110 Ground Lug

Elbow, Loadbreak, 1/0, 175 mil (Includes Sealing Kit #2391)

Cap, Protective Insulated 200AClamp, Ground Rod 5/8", SmallRod, Ground 5/8" x 8'Conductor, Wire BSDC #4 SLD

Voltage-Reset Fault Indicator, 400A Trip, 1Ø UG2

89

765

1

Connector, Crimpet, #4 to #2 (2C4)

DESCRIPTION

211

842929

2651

121

1

11

2694

376454

1124281

UT21QTY.

2

S/N1312

Rod, Ground 5/8" x 8'Clamp, Ground Rod 5/8", Small

Bolt, Unistrut, Padmount Tie Down

Conductor, Wire BSDC #4 SLD

Elbow, Loadbreak, 1/0, 175 mil (Includes Sealing Kit #2391)

Pad, Transformer 42" x 42"Ground Lug

1

Connector, Crimpet, #4 to #2 (2C4)

84212

2811

11

112

929

1124376

21

13122694

2521 Bushing, Standoff Insulated 200A3

2

4

56

Nut, Spring-Loaded, Galv, 1/2", Unistrut

Connector, Z-Bar #6-500 MCM + St. LtCover, Connector Z-Bar

Washer, 2" x 3" x 3/16" w/ 9/16" Slotted Hole1415

1312

3322

226622651415920193

193

2266

92014152265

3

223

Washer, 2" x 3" x 3/16" w/ 9/16" Slotted HoleNut, Spring-Loaded, Galv, 1/2", Unistrut

Connector, Z-Bar #6-500 MCM + St. LtCover, Connector Z-Bar

454

16 Connector, Crimpet, #2 to #2 (2C2) 4551

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UT21-UT22 UT21-UT222 2 10/98 1400

SINGLE PHASEPADMOUNT TRANSFORMER ASSEMBLIES

LOOP FEED

0 2/22/00 HWH MA1 9/23/04 LB AH2 12/29/04 LB AH3 4/29/09 CM AH

Rev 3: Changed to Voltage-reset fault indicator.

Voltage-Reset Fault Indicator, 400A Trip, 1Ø UG

1110

89

7

1415

1312

ITEMNO.

ITEMNO.

RADIAL FEED UT24 N.O. LOOP FEEDS UT25(2) FUTURE

(1) LOOP FEED UT26

FAULT INDICATOR

NORMALLY OPEN

WEATHERPROOFTAG & COIL COND.

(1) FUTURE

LOOP FEED UT27 (2) LOOP UT28

SEE US6 FOR SECONDARY CONNECTORS DETAILS

NECESSARY.

LEAVE SLACK IN CONCENTRICNEUTRALS FOR FUTUREOPERATION. ADD #2 BCSD IF

ONLY THE COMPONENTS REQUIREDIN THE MATERIAL LISTS.

NOTE: INSTALL GROUNDING LUG

THIS DRAWING IS TYPICAL. USE

FRONT VIEW OF TRANSFORMER UT28

OUT

*

*

- GROUNDING LUGTO TANK

ELBOW CAN BE INSTALLED

TERMINATE CABLES WITHENOUGH LENGTH SO EACH

ON ANY POSITION.

*

OUT IN

8

8

2 5

6

10

1

7

3

9 TAG

TAG

TAG

TAG

TAG

TAG

15

7

*11

17

16

12 13 14

3"

2"

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UT24-UT28 UT24-UT281 4 10/94 1400

SINGLE PHASEPADMOUNT TRANSFORMER ASSEMBLIES RADIAL

OR LOOP FEED WITH FEED-THROUGH BUSHING

1 7/15/02 JEH TR2 9/23/04 LB AH3 12/29//04 LB AH4 4/29/09 CM AH

F

F

Rev 4: Changed to Voltage-reset fault indicators.

Bushing, Standoff Insulated 200A

Rod, Ground 5/8" x 8'Clamp, Ground Rod 5/8", SmallCap, Protective Insulated 200A

Conductor, Wire BSDC #4 SLDConnector, Crimpet, #4 to #2 (2C4)Insert, Feed-ThroughPad, Transformer 42" x 42"Ground Lug

7

1110

89

56

43

3766

11

842929

1 237

28111 1124

21

265252

6 Rod, Ground 5/8" x 8'

Ground LugPad, Transformer 42" x 42"Insert, Feed-ThroughConnector, Crimpet, #4 to #2 (2C4)Conductor, Wire BSDC #4 SLD

Elbow, Loadbreak. 1/0, 200A, 175 mil12

11

8910

7

Elbow, Loadbreak. 1/0, 200A, 175 milVoltage-Reset Fault Indicator, 400A Trip, 1Ø UG

Cap, Protective Insulated 200AClamp, Ground Rod 5/8", Small

Bushing, Standoff Insulated 200A

1

54

23

11241

DESCRIPTIONS/NQTY.

21

13122694

UT25

1 842

454111

237929

6 376

DESCRIPTION

13122

12

281265

1 1

2694252

UT24QTY. S/N

1314

92022 1415

193212

1516 22663

22653

16

1415

1312

9201415226522663

23

22 193

Cover, Connector U.G.Connector, Z-Bar #6-500 MCM + St. LtWasher, 2" X 3" X 3/16" w/ 9/16" slotted holeNut, Spring-loaded, Galv, 1/2", UnistrutBolt, Unistrut, Padmount Tie Down

Cover, Connector U.G.Connector, Z-Bar #6-500 MCM + St. LtWasher, 2" X 3" X 3/16" w/ 9/16" slotted holeNut, Spring-loaded, Galv, 1/2", UnistrutBolt, Unistrut, Padmount Tie Down

1 454

17 Connector, Crimpet, #2 to #2 (2C2) 4551

4551Connector, Crimpet, #2 to #2 (2C2)17

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UT24-UT28 UT24-UT282 4 10/94 1400

SINGLE PHASEPADMOUNT TRANSFORMER ASSEMBLIES RADIAL

OR LOOP FEED WITH FEED-THROUGH BUSHING

1 7/15/02 JEH TR2 9/23/04 LB AH3 12/29/04 LB AH4 4/29/09 CM AH

Rev 4: Changed to Voltage-reset fault indicators.

Voltage-Reset Fault Indicator, 400A Trip, 1Ø UG

ITEMNO.

ITEMNO.

Ground LugPad, Transformer 42" x 42"Insert, Feed-Through

11109

Connector, Crimpet, #4 to #2 (2C4)Conductor, Wire BSDC #4 SLD

Elbow, Loadbreak, 1/0, 200A, 175 mil

Cap, Protective Insulated 200AClamp, Ground Rod 5/8", SmallRod, Ground 5/8" x 8'

Bushing, Standoff Insulated 200A4

78

65

321

842111

929237

UT27DESCRIPTION

2651

61

376454

11

1124281

11

2522694

QTY.2

S/N1312

7

1110

89

56

43

12

DESCRIPTIONS/NQTY.

UT26

13

16

1415

2 920

3 2266

23

14152265

193212

Cover, Connector U.G.Connector, Z-Bar #6-500 MCM + St. LtWasher, 2" X 3" X 3/16" w/ 9/16" slotted holeNut, Spring-loaded, Galv, 1/2", UnistrutBolt, Unistrut, Padmount Tie Down

Elbow, Loadbreak, 1/0, 200A, 175 mil

Bushing, Standoff Insulated 200ACap, Protective Insulated 200AClamp, Ground Rod 5/8", SmallRod, Ground 5/8" x 8'Conductor, Wire BSDC #4 SLDConnector, Crimpet, #4 to #2 (2C4)Insert, Feed-ThroughPad, Transformer 42" x 42"Ground LugBolt, Unistrut, Padmount Tie DownNut, Spring-loaded, Galv, 1/2", UnistrutWasher, 2" X 3" X 3/16" w/ 9/16" slotted holeConnector, Z-Bar #6-500 MCM + St. LtCover, Connector U.G. 3

3222111

6111123 1312

26942522652811124376

237929842193920141522652266

1514

16

1213

4541

4552Connector, Crimpet, #2 to #2 (2C2)17

4551Connector, Crimpet, #2 to #2 (2C2)17

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UT24-UT28 UT24-UT283 4 10/94 1400

SINGLE PHASEPADMOUNT TRANSFORMER ASSEMBLIES RADIAL

OR LOOP FEED WITH FEED-THROUGH BUSHING

1 7/15/02 JEH TR2 9/23/04 LB AH3 12/29/04 LB AH4 4/29/09 CM AH

Rev 4: Changed to Voltage-reset fault indicators.

Voltage-Reset Fault Indicator, 400A Trip, 1Ø UG

Voltage-Reset Fault Indicator, 400A Trip, 1Ø UG

ITEMNO.

ITEMNO.

UT28

8910

4

7

56

1

32

DESCRIPTIONQTY. S/N

11

Bushing, Standoff Insulated 200A

Rod, Ground 5/8" x 8'Clamp, Ground Rod 5/8", SmallCap, Protective Insulated 200A

28111 1124

-1

265252

Elbow, Loadbreak, 1/0, 200A, 175 mil 32

13122694

Conductor, Wire BSDC #4 SLDConnector, Crimpet, #4 to #2 (2C4)

6 376

Insert, Feed-Through 1 237Pad, Transformer 42" x 42" 1 929Ground Lug 1 842

Washer, 2" X 3" X 3/16" w/ 9/16" slotted holeConnector, Z-Bar #6-500 MCM + St. Lt

Nut, Spring-loaded, Galv, 1/2", UnistrutBolt, Unistrut, Padmount Tie Down

Cover, Connector U.G.

13

16

1415

122 920

3 2266

23

14152265

2 193

DESCRIPTIONQTY. S/N

4541

17 Connector, Crimpet, #2 to #2 (2C2) 4552

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UT24-UT28 UT24-UT284 4 10/94 1400

SINGLE PHASEPADMOUNT TRANSFORMER ASSEMBLIES RADIAL

OR LOOP FEED WITH FEED-THROUGH BUSHING

1 7/15/02 JEH TR2 9/23/04 LB AH3 12/29/04 LB AH4 4/29/09 CM AH

Rev 4: Changed to Voltage-reset fault indicators.

Voltage-Reset Fault Indicator, 400A Trip, 1Ø UG

ITEMNO.

RADIAL FEEDNORM. OPEN ORFUTURE LOOP FEED LOOP FEEDUT30 UT31 UT32

NOTE: SPECIFY I.D. TAGS AS REQUIRED.

FRONT VIEW OF TRANSFORMER(UT32 SHOWN)

H1B

H2B

H3B

H1A

H2A

H3A

LOAD SOURCE

USE #4 BSDC FOR PROTECTIVECAP GROUNDING.

(IN)(OUT)

TAG

TAG

TAG

TAG

TAG

TAG

AØ

BØ

CØ

AØ

BØ

CØ

NOTE HOW PETCONNECTORS AREORIENTED FORCLEARANCE

7

10 11

12

6 5

9

1 1

3

8

13

13

3

9

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UT30-UT32 UT301 3 10/99 1400

THREE PHASEPADMOUNT TRANSFORMER ASSEMBLIES

1 2/23/00 HWH MA2 9/23/04 LB AH3 4/29/09 CM AH

F

F

F

Rev 3: Changed to Voltage-reset fault indicators.

RADIAL FEED UT32UT31UT30

NOTE: SPECIFY I.D. TAGS AS REQUIRED.

FUTURE LOOP FEED LOOP FEED

(UT30 SHOWN)

CAP GROUNDING.USE #4 BSDC FOR PROTECTIVE

FRONT VIEW OF TRANSFORMER

NORM. OPEN OR

TAG

H2A

H3A

H1A

TAG

H2B

H3B

TAG

H1BAØ

BØ

CØ

CLEARANCEORIENTED FORCONNECTORS ARENOTE HOW PET

9

8

56

7

41

12

10 11

(OUT) (IN)SOURCELOAD

7

8

139

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UT30-UT32 UT302 3 10/99 1400

THREE PHASEPADMOUNT TRANSFORMER ASSEMBLIES

1 2/23/00 HWH MA2 9/23/04 LB AH3 4/29/09 CM AH

Rev 3: Changed to Voltage-reset fault indicators.

Rod, Ground 5/8" x 8'Clamp, Ground Rod 5/8", SmallCap, Protective Insulated, 200A

Connector, Crimpet, #4 to #2 (2C4)

Bolt, Machine, 1/2 x 2" SS w/ Bronze Nut & Belleville WasherCover, PET, 8 Position

8

1211

910

5

76

43

416

21821389

1

4

454

2129

28111 1124

3 265

12

DESCRIPTIONS/NQTY.

63

1312

UT31

Bushing, Standoff Insulated 200A 252Voltage-Reset Fault Indicator, 400A Trip, 1Ø UG 3 2694

Conductor, Wire BSDC #4 SLD 10 376

Ground Lug 2 842

Bolt, Machine, 1/2 x 2" SS w/ Bronze Nut & Belleville WasherCover, PET, 8 Position

Ground LugConnector, Crimpet, #4 to #2 (2C4)Conductor, Wire BSDC #4 SLD

Clamp, Ground Rod 5/8", SmallRod, Ground 5/8" x 8'

1211

910

8

5

76

3

416

21821389

24

18422129

454

1 281

101

3761124

3 2694Elbow, Loadbreak, 1/0, 200A, 175 mil1

DESCRIPTIONQTY. S/N

6 1312

UT32

Bolt, Machine, 1/2 x 2" SS w/ Bronze Nut & Belleville Washer11Cover, PET, 8 Position12

Elbow, Loadbreak, 1/0, 200A, 175 mil

Rod, Ground 5/8" x 8'Clamp, Ground Rod 5/8", SmallCap, Protective Insulated 200A

Conductor, Wire BSDC #4 SLDConnector, Crimpet, #4 to #2 (2C4)Ground LugConnector, PET, #2-750 Al/Cu, 6 Position10

9

78

6541

164 2182

138942

2129842

101

1376454

112413

281265

3 1312

DESCRIPTION UT30QTY. S/N

Elbow, Loadbreak, 1/0, 200A, 175 mil

13 Connector, Crimpet, #2 to #2 (2C2) 4552

4554Connector, Crimpet, #2 to #2 (2C2)13

4554Connector, Crimpet, #2 to #2 (2C2)13

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UT30-UT32 UT303 3 10/99 1400

THREE PHASEPADMOUNT TRANSFORMER ASSEMBLIES

1 2/23/00 HWH MA2 9/23/04 LB AH3 4/29/09 CM AH

Connector, PET, #2-750 Al/Cu, 6 Position

Connector, PET, #2-750 Al/Cu, 6 Position

Rev 3: Changed to Voltage-reset fault indicators.

Voltage-Reset Fault Indicator, 400A Trip, 1Ø UG

ITEMNO.

ITEMNO.

ITEMNO.

Front

TopView

Front

Box Pad, 1Ø Transformer, Fiberglass1

DESCRIPTION

1 2433

QTY. S/N

42"

38"

24"

21"

12"

7"

6"

38"

6"

15"

20"

42"

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UTB UTB1 1KJP

12/29/04 1400

SINGLE PHASEPADMOUNT TRANSFORMER

BOXPAD (BASEMENT)

ITEMNO.

NOTES:

1. THIS IS A MANUFACTURED PAD S/N 929

2. SEE UTP6 (2 OF 2) FOR INSTALLATION INSTRUCTIONS.

REV 1 - REVISIONS MARKED WITH A STAR

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UTP1 (SMTP) UTP11 1 9/94 1400

TRANSFORMER PADSINGLE PHASE 25 TO 75 KVA

1 REVISIONS MARKED WITH A STAR

1 2/23/00 HWH MA

2. SEE UTP3 FOR INSTALLATION INSTRUCTIONS.

AT WESCO IN PORTLAND, OREGON. NUMBER PH48461826G35. AVAILABLE

1. THIS IS A QUAZITE PAD. CATALOG

Notes:

CPU S/N 930.

46"48"

26 916 "

18 916"

5 12"

9 1116 "

5"

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UTP2A UTP2A1 1 4/94 1400

TRANSFORMER PADSINGLE PHASE

100 KVA1

1 2/23/00 HWH MA

SECTION "A-A"

FRONT OF TRANSFORMER

A A

(NOTE 6)LV SIDE HV SIDEPLAN VIEW

GRAVEL 5/8" MINUS

FRONT VIEW

GROUNDROD FUTURE

CL

27"

CL 19"

WITH PAD TOPCONDUIT FLUSH

GROUNDROD

SECONDARY DUCTS

36" RADIUS

24" OR 36" PRIMARY DUCTS

PAD

46"

48"

100 KVA ONLY

Notes:1. AIC FOR 100KVA TRANSFORMER IS 14,000 AMPS.

2. HIGH AND LOW VOLTAGE DUCTS MUST BE WITHIN THEIR DESIGNATED AREAS.

3. ALL DUCTS SHALL BE IN PLACE AND APPROVED PRIOR TO TRANSFORMER INSTALLATION.

4. IT SHALL BE THE RESPONSIBILITY OF THE OWNER OR HIS REPRESENTATIVE TO COMPLY WITH ALL APPLICABLE CODE REQUIREMENTS.

5. THE PAD SHALL BE FURNISHED BY THE CUSTOMER.

6. THE FRONT SIDE MUST HAVE 10' CLEAR ACCESS FOR MAINTENANCE.

7. ALL DUCT ENDS SHALL EXTEND PAST THE EDGE OF THE PAD BY 48 INCHES MINIMUM.

8. RADIUS OF SECONDARY BEND SHALL BE 24" OR 36".

9. DEPTH OF BURIAL OF CONDUITS SHALL BE AS SHOWN ON UA1.

10. THE PAD SHALL BE LOCATED SO THAT NO PART OF THE TRANSFORMER IS CLOSER THAN 10 FEET TO A COMBUSTIBLE SURFACE, WINDOWS OR DOORS OR 3 FEET TO A NON-COMBUSTIBLE STRUCTURE.

11. MINIMUM PRIMARY DUCT SIZE SHALL BE 2 INCHES.

12. THE FLAT GRAVEL SURFACE SHALL BE AT LEAST 54" x 54" WITH CONDUITS POSITIONED AS SHOWN ON THE PLAN VIEW.

13. THE 5/8" MINUS GRAVEL FOR THE PAD BASE MUST BE WELL COMPACTED TO AVOID FUTURE SETTLING. THE GRAVEL LAYER MUST BE AT LEAST 12" THICK BUT MAY REQUIRE ADDITIONAL COMPACTED MATERIAL DEPENDING ON THE EXISTING SOIL STABILITY.

14. ANY BACKFILLING TRENCHING

3.5"

42"36" to

48"

REV 1: ADDED DIMENSIONS AND AIC

1Ø PADMOUNT TRANSFORMER CONDUIT ORIENTATION (100 KVA)

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UTP3 UTP31 1 9/94 1400

1Ø TRANSFORMER PAD ORIENTATIONAND CONDUIT INSTALLATION

(100 KVA)1 ADDED DIMENSIONS AND AIC

0 2/23/00 HWH MA1 1/26/04 LB AH

1. ALL CONCRETE SHALL BE 2500 PSI AND HAVE A SLUMP OF 4" TO 6"2. REINFORCING SHALL CONFORM TO A.S.T.M. DESIGNATION A15 AND A305.3. TROWEL SMOOTH SURFACES AND BRUSH FINISH. ROUND ALL EDGES,

MANUFACTURERS NOTES:

REINFORCING SCHEDULEMARK NO. SIZE LENGTH REMARKS

123 4

45

1/2"1/2"1/2"

3'-4"5'-1"6'-9"

""

STRAIGHT

MARK 2

MARK 3

MARK 3

MARK 3

MARK 2

MARK 2

MARK 2

MARK 1

MARK 1

MARK 1

MARK 1

MARK 1

1'-3"

7'-0"

1'-3"

1'-3

"

5-4"

6"3'

-7" 1-1/2"

1-1/2"

PLAN

A A

6"

2-1/2"SECTION "A-A"

CONCRETE PAD DETAILS FOR 3Ø 75 KVA THRU. 1500 KVAPADMOUNT TRANSFORMERS

4'-6"

4- 1 1/4"NC INSERTS THROUGH THE PAD

MARK 3

1. THIS PAD IS AVAILABLE PRECAST FROM UTILITY VAULT COMPANY ORPACIFIC INTERNATIONAL PIPE ENTERPRISES, INC. (CPU S/N 2170).

2. THIS PAD IS ADAQUATE FOR UP TO 6 CONDUCTORS PER PHASE. SEE UPT4-6IF MORE CONDUCTORS ARE REQUIRED.

GENERAL NOTES:

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UTP4 UTP41 1 9/94 1400

TRANSFORMER PADTHREE PHASE

75 TO 1500 KVA0

0 2/23/00 HWH MA1 8/17/03 LB DK

PRI SEC

1

2

3

4

5

3

1

1

1

1

2

3

4

5 2

3

FRONT VIEW

SIDE VIEWTOP VIEW

7'

5'-4"

6"

2'

4'

3'-6"

NOTES:

PERMISSIBLECONDUITLOCATIONS(PRIMARY)

PERMISSIBLECONDUIT LOCATIONS(SECONDARY)

VAULT 4' X 6' X 3'-6", UTILITY VAULT CO.#644LA OR EQUAL.

COVER 4' X 4' X 6", UTILITY VAULT CO.#44-332P OR EQUAL.

PAD 64" X 84" X 6" W/15" X 54" OPENINGUTILITY VAULT CO. PAGE 53.3 OR EQUAL.

COMPONENTS

1

2

3

LOCKING BOLT SHALL BE PER REA STANDARD PENTA HEAD 1/2" BOLT ANDRECESS.

COMPONENT SHALL BE PLACED ON 12 INCHES OF 1 INCH-MINUSCRUSHED ROCK.

COMPONENT MAY BE PLACED ON UNDISTURBED EARTH OR 12 INCHESOF COMPACTED 5/8 INCH-MINUS CRUSHED ROCK.

CUSTOMER SHALL INSTALL ALL 3 COMPONENTS SHOWN, ALL SECONDARYCONDUITS INTO COMPONENT , ALL SECONDARY CABLES WITH A MINIMUM10' OF EXCESS IN VAULT FOR MAKE UP AND ENTER ONLY IN THE AREASSHOWN.

ALL PRIMARY CONDUITS SHALL ENTER THE PAD FROM OUTSIDE OF THEVAULT AND ONLY IN THE LOCATIONS SHOWN.

EQUALS MUST BE APPROVED BY CLARK PUBLICUTILITIES PRIOR TO INSTALLATION

THIS PAD IS REQUIRED IF MORE THAN 6 CONDUCTORS PER PHASE ARE BEING INSTALLED.

6

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UTP4-6 UTP4-61 1 9/94 1400

PRECAST PAD AND VAULTFOR THREE PHASE TRANSFORMERS

0

0 2/23/00 HWH MA

SECTION "A-A"

NOTES:

28750 - 1500225002075 - 300

"A" INCHESKVA

48" MIN.

6"

5/8" MINUSCRUSHED ROCK

WITH PAD TOPCONDUIT FLUSH

CRUSHED ROCK5/8" MINUS

LOW VOLTAGE SIDE

HIGH VOLTAGE SIDE

"A"

4"

FRONT SIDE (NOTE 6)

A

A

(SECONDARY COMPARTMENT)

36"-

42"

BUSHING

LC

LC

EXISTING OR CURB GRADE

A B C BC A

R2 - MINOR DRAWING CHANGES

3Ø PADMOUNT TRANSFORMER CONDUIT ORIENTATION

* (3) 2" conduits,

*

normally (1) 4"is used

**Varies by manufacturer

TYPICAL**

7'-0"

5'-4"

GROUND ROD

R1 - CONDUIT LAYOUT / ELEVATIONS

R3 - ADDED DIMENSIONS AND AIC AND REMOVED SECONDARY FUTURES

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UTP6 UTP61 2 10/98 1400

3Ø TRANSFORMER PAD ORIENTATIONAND CONDUIT INSTALLATION

2 MINOR DRAWING CHANGES

1 2/23/00 HWH MA2 7/15/02 JEH TR3 1/26/04 LB AH4 12/29/04 LB AH

1400 U

nd

erg

ro

un

d P

ad

T

ra

nsfo

rm

er

1400

U

nd

erg

ro

un

d P

ad

T

ra

nsfo

rm

ers

FACE ONE CONDUIT TOWARDS PRIMARYSOURCE OTHERS TOWARD FUTUREEXTENSION.

PRIMARY RACEWAY TO CLEAREDGE OF PAD BY 48". SIZE& NUMBER AS REQ'D. 36"RADIUS.

R4 - UPDATED FOR ALL-CONDUIT SYSTEM

1. LOCATE HIGH VOLTAGE CONDUITS IN THE CENTER OF THE HIGH VOLTAGE SIDE.

2. LOW VOLTAGE CONDUITS MUST BE WITHIN THE SHADED AREA.

3. THE CONCRETE PAD AND ALL CONDUITS SHALL BE IN PLACE AND APPROVED BY THE DISTRICT PRIOR TO TRANSFORMER INSTALLATION.

4. IT SHALL BE THE RESPONSIBILITY OF THE OWNER OR A REPRESENTATIVE OF THE OWNER TO COMPLY WITH ALL APPLICABLE CODE REQUIREMENTS.

5. THIS INTRODUCTION SUPPLEMENTS THE INDIVIDUAL CONCRETE PAD DETAILS SUCH AS UTP4 OR ANY SPECIAL DISTRICT DESIGN.

6. REFER TO UPTC FOR CLEARANCES.

7. THE PAD SHALL BE LOCATED SO THAT NO PART OF THE TRANSFORMER IS CLOSER THAN 10 FEET TO THE COMBUSTIBLE SURFACE, WINDOWS, DOORS, OR 3 FEET TO A NON-COMBUSTIBLE SURFACE.

8. ANY BACKFILLING UNDER THE TRANSFORMER PAD MUST BE BACK FILLED WITH 5/8" MINUS COMPACTED CRUSHED ROCK, COMPACTED IN LIFTS, TO PREVENT FUTURE PAD SETTLING.

FRONT VIEW

GRAVEL 5/8" MINUS

PLAN VIEW

8" MIN.

FINAL GRADE

PAD

PRIMARY DUCTS

24" OR 36" RADIUS

HV SIDE

LV SIDE (NOTE 5)

27" AA

FRONT OF TRANSFORMER

NOTES:

SECTION "A-A"

12"CL

LC

GROUNDROD

GROUNDROD

CONDUIT FLUSHWITH PAD TOP

36" RADIUS

SECONDARY DUCTS

4"

1Ø PADMOUNT TRANSFORMER CONDUIT ORIENTATION (25-75 KVA)

FUTURE

42"

42"

25-75KVA Transformer*

100KVA transformer pad is 48"x46". See standard UTP2A and UTP3.*

3.5"

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UTP6 UTP62 2 10/98 1400

1Ø TRANSFORMER PAD ORIENTATIONAND CONDUIT INSTALLATION

2 MINOR DRAWING CHANGES

1 2/23/00 HWH MA2 7/15/02 JEH TR3 1/26/04 LB AH4 12/29/04 LB AH

1. AIC FOR 25 TO 75KVA TRANSFORMERS IS 10,000A.

2. HIGH AND LOW VOLTAGE DUCTS MUST BE WITHIN THEIR DESIGNATED AREAS.

3. ALL DUCTS SHALL BE IN PLACE AND APPROVED PRIOR TO TRANSFORMER INSTALLATION.

4. IT SHALL BE THE RESPONSIBILITY OF THE OWNER OR HIS REPRESENTATIVE TO COMPLY WITH ALL APPLICABLE CODE REQUIREMENTS.

5. THE PAD SHALL BE FURNISHED BY THE CUSTOMER.

6. FRONT SIDE MUST HAVE 10' CLEAR ACCESS FOR MAINTENANCE.

7. ALL DUCT ENDS SHALL EXTEND PAST THE EDGE OF THE PAD BY 48 INCHES MINIMUM.

8. RADIUS OF SECONDARY DUCT BEND SHALL BE 24" OR 36".

9. DEPTH OF BURIAL OF CONDUITS SHALL BE AS SHOWN ON UA1.

10. MINIMUM PRIMARY DUCT SIZE SHALL BE 2 INCHES.

11. THE FLAT GRAVEL SURFACE SHALL BE AT LEAST 48" x 48" WITH CONDUITS POSITIONED AS SHOWN ON THE PLAN VIEW.

12. THE 5/8" MINUS GRAVEL FOR THE PAD BASE MUST BE WELL COMPACTED TO AVOID FUTURE SETTLING. THE GRAVEL LAYER MUST BE AT LEAST 12" THICK BUT MAY REQUIRE ADDITIONAL COMPACTED MATERIAL DEPENDING ON THE EXISTING SOIL STABILITY. ANY TRENCHING UNDER OR NEAR THE TRANSFORMER PAD MUST BE BACKFILLED WITH COMPACTED CRUSHED ROCK TO PREVENT FUTURE PAD SETTLING.

13. THE PAD SHALL BE LOCATED SO THAT NO PART OF THE TRANSFORMER IS CLOSER THAN 10 FEET TO A COMBUSTIBLE SURFACE, WINDOWS, DOORS OR 3 FEET TO A NON-COMBUSTIBLE SURFACE.

PLAN VIEWTYPICAL PAD

FRONT

OPTIONALCTR. POST

OPTIONALCTR. POST

COUPLING

DO NOT FILLCTR. POSTWITH CONC.

CAP

3'-0

" m

in.

2'-0

" m

in.

DETAIL "A"

FRONT VIEW

FINISHGRADE

4" STEEL PIPE,CONCRETE-FILLED

5'-0" MAX.(SEE NOTE 2)

CAPOPTIONAL

DIMENSIONS AND CONDUITSIZE TO BE PROVIDED BYPROJECT ENGINEER.

3'-0

" m

in.

2'-0

"

* *

*

*

18"

@45°

DATE

SECTIONAPP:

RCONSTRUCTION STANDARDS

DATE:

ENGRREVISIONS

OPS

CAD FILE:PAGE:

of UTP9 UTP91 1 9/94 1400

TYPICAL BARRIER INSTALLATION TOPROTECT PADMOUNTED EQUIPMENT

0 2/23/00 HWH MA1 5/30/07 LB AH2 12/14/09 KJP

DETAIL "A"

min

.

Rev 2: Corrected dimensions on barrier to match Commercial Electric Service Handbook.

Notes:

1. Typical locations of barriers positioning will vary depending on the following conditions. a. Physical location of equipment with respect to hazards. b. Type of equipment to be protected and accessibility required.2. If distance between corner barriers exceeds 5 ft., A ctr. post may be required similar to corner post except center post on front side of padmount device may be constructed as det. "A".3. Project Engineer will determine and indicate number, size, and position of barrier posts.4. Posts of 4" steel pipe, concrete-filled or substitute of equal strength to be set in concrete. Use same mixture as pad.5. See WAC 296-46-480 Para. 4, rules and regulations for installing electric wires and equipment.

Clark Public Utilities — Commercial Electric Service Handbook

Chapter 3: Commercial Underground Services / January 2011 � 17

Transformer location and access

Underground electrical facilities must be readily accessible by the utility duringconstruction and for future operation and maintenance. The area around padmounted electrical equipment must provide a clear and level working spaceand remain free from obstructions such as landscaping, poles, retaining walls,structures, fences, etc.

All transformers and padmounted equipment are to be located:

� Within 10 feet of a drivable surface but not closer than 5 feet (Figure 3).

� With the front of the equipment (door and lock side) facing toward the drivablesurface.

� With the transformer pad parallel to the edge of the drivable surface.

� Allowing 10 feet of clearance in front and 3 feet from the back and sides of theequipment (Figure 3).

� At least 2 feet from a sidewalk for pedestrian safety.

Figure 3 Commercial padmounted transformer location and access

drivable surface

VIEW FROM ABOVE

curb

transformer

3 ft. minimum of clear working spacefrom back and sides

5 ft. minimum to 10 ft. maximum of clear working space from drivable surface to front of transformer pad

edge of transformer pad

position transformer with door and lock facing the drivable surface

2 ft. minimum of clear working space from a sidewalk to front of transformer pad

sidewalk

door and lock

Clark Public Utilities — Commercial Electric Service Handbook

18 � Chapter 3: Commercial Underground Services / January 2011

Transformer safety clearances

Clearances from padmounted transformers to structures are measured from the nearest metal portion of the transformer to the structure or any overhang. The clearance from a building is 10 feet if the building has combustible walls, and 3 feet if the building has non-combustible walls as shown in Figure 4. Table 4 provides additional safety clearances that apply to any oil-filled electricalequipment.

non-combustiblestructure and roof

combustiblestructure and roof

20 ft.

10 ft.

10 ft. minimum

operable windowor other opening

door or other opening

gas meter

transformer

transformer

transformer

hydrant

fuel dispensingfacilities

fireescape

10 ft.

10 ft.

10 ft.

10 ft.15 ft.

6 ft.

fuelstorage

3 ft.

min.

3 ft.

Figure 4 Commercial padmounted transformer minimum safety clearances

Clark Public Utilities — Commercial Electric Service Handbook

20 � Chapter 3: Commercial Underground Services / January 2011

� If the distance between the corner posts exceeds 5 feet, a removable center post is required (Figure 5).

� If a removable center post is installed, the threaded joint requires treatment with an anti-seizing agent.

� Paint exposed section of post “traffic yellow.”

Figure 5 Guard post (bollard) installation for commercial transformers

FRONT VIEW

VIEW FROM ABOVE

3 ft.minimum

18 in.minimum

on 45°

removable center post,as required

2 ft.

domed concrete

FINAL GRADE

4 in. galvanized/steel pipe,

concrete filled

4 in. galvanized/steel pipe,

concrete filled

concrete fill

removable center post,as required

coupling

do not fillcenter post

with concrete

edge of transformer pad

commercial transformer

door and lock

edge of transformer

NOTE: Additional guard posts may be required at back and sides of transformer.