BLAST BLANKET

TESTS ON NETWORK

TRANSFORMER

APIC-2011

NETWORK TRANSFORMER

HV TERM WIPE

SLEEVE

HV TERM

COMP.

HV

SWITCH

COMP.

NETWORK

PROTECTOR

NTWK PROTECTOR

LOW VOLTAGE

TERMINAL

NETWORK

PROTECTOR

BLAST PRESSURE

BUILDINGS ARE DESIGNED FOR A WIND

PRESSURE OF : 34 LBS/M2 0.24PSI

@ 1 METRE a 25 KA ARC WOULD CREATE A

PRESSURE OF 0.29 PSI

COMBUSITON OF OIL-AIR MIXTURE IN A

41M3 VOLUME WOULD RELEASE 162MJ

HEAT ENERGY AND THE PRESSURE RISE

WOULD BE 14.5 ATM

1ATM = 101.325 KPa = 14.69 psi

HAZARD CATEGORY

NFPA 70E-2000

CAT 1 : 5 CAL/CM2

CAT 2 : 8 CAL/CM2

CAT 3 : 25 CAL/CM2

CAT 4 : 40 CAL/CM2

1 joule = 0.2338 cal

5 joules or 1.2 cal second degree curable burn

WHY BLAST BLANKETS

BLAST BLANKETS ARE SUPPOSED TO PROTECT A WORKER FROM THE HAZARD OF A FAILURE OF AN ENERGIZED NETWORK TRANSFORMER HV CHAMBER WHICH REQUIRES A CATEGORY 4 PROTECTION

BB- PROTECT BY DIVERTING OR BLOCKING THE BLASTS

PURPOSE OF THE TEST

TO FIND OUT THE BEST METHOD OF

INSTALLING BLAST BLANKETS.

TO PROTECT EPCOR CREWS WHILE

WORKING EITHER INSIDE AN ENERGIZED

NETWORK VAULT OR ON THE ROOF OF

AN ENERGIZED VAULT

TYPES OF BLAST BLANKETS

USED

TWO TYPES OF BLANKETS WERE

USED:

OBERON MAKE 25 KA BLAST

BLANKETS ( 8X5)’

SALISBURY MAKE 40 KA BLAST

BLANKETS (3X5)’

Installation details Top view

36”

Cal 1 @ 50” above

floor

56”

15”

45”

41”

9”

Cal 2 @ 40” above

floor

12.42”

White Cotton

White Cotton

62.42”

P1

P2

Specially built Vault used for

Testing

VAULT SIZE: 2.95 (W) X 3.3 (H) X 4.4 (D) m

VAULT SIZE: 2.95 (W) X 3.3 (H) X 4.2 (D) m (

vent ( 0.6m)

BB WRAP AROUND PETROLATUM

FILLED HV TERM COMP.

25 kA Oberon

blanket

wrapped

loosely on the

transformer

HV

compartment

Test 1 -videos

Play normal speed video: Test 10-2794

EPCOR\Blast Blanket Testing - June

2010\Normal Video\Test_10-2794.avi

Play HS video: Test HS:10-2794 EPCOR\Blast Blanket Testing - June 2010\HS

Video\HS10-2794.cine

BURNT PETROLATUM

MATERIAL SPLASHED

ONTO THE WALL

Burnt Petrolatum on the floor

TERMINATION CHAMBER

WALLS DEFOREMD, ITS

COVER BLOWN OFF AND

ALL THE BOLTS SHEARED

OFF.