1. APTRANSCO
DGNP 132/33 kvSS
100% Reliability Against Contamination Induced Flashovers
with Dow Corning Sylgard HVIC + Coating
By Project Sales Corp, Visakhapatnam
Some Application Pictures

2. The Rationale for Application of Sylgard HVIC + Coating at
DGNP 132 kv SS
DGNP 132 kv SS is located in Visakhapatnam. The
substation, situated near the port area caters to the
requirements of the growing power needs of the defence –
The Indian Navy. Surrounded by a iron ore dump of
Hygrade Pellets Limited on one side, a flyover with heavy
vehicular traffic on the other, industries like Rain Calcining
on the left, and the sea on its right, this substation is
vulnerable to contamination induced outages from both the
salinity as well as the industrial pollutants.
The contaminated surfaces can lead to surface leakage
currents during rains or early morning dew, develop into dry
bands and arcing and lead to eventual flashovers resulting
in the loss of revenue to APTRANSCO as well as customer
dis-satisfaction. To ensure that there are no revenue related
losses due to outages, and ensure uninterrupted supply to
the Indian Navy, APTRANSCO proposed to apply Sylgard
HVIC+ to the equipments at the SS. In the coming slides,
you will see pictures of Sylgard HVIC+ application onto
these equipments.
The new power plant of Essar is right Crane Masts at the port. NMDC Crushing Plant
Sylgard HVIC+ is a proven cost-effective long-term
Behind this flyover
maintenance free solution to prevent contamination build-up
Seen in the picture clockwise: the recently constructed flyover for heavy vehicles carrying all kinds of and wetting of the insulator surface. Its low molecular
raw materials to industries in the region, while the road underneath caters to daily commuters to the
Naval Base and many industries in this zone; the Hygrade Pellets ore dumping yard, with the NMDC
weight silicones also ensure contamination particles seating
crushing plant in the background; a closer look at the open dumping yard; the MRS of the Navy (in on the insulator surface do not wet and form a conductive
the background, some cranes mast can be seen). The sea is hardly a mile away from here. What’s solution thus interrupting the flashover process at an early
not seen in the picture behind the flyover is the pelletization plant of Hygrade pellets.
stage.

3. The Application Process
1. Cleaning of Insulators
• The contamination on the insulators are cleaned using solvents to dissolve any
previously coated grease or stubborn dirt, followed with IPA to remove dust and other
contaminants and primed with DC 1200 RTV.
2. Spraying of Sylgard HVIC + on the equipments
• Sylgard HVIC +, a single component silicone coating, is sprayed onto the equipments
using spray guns. Project Sales Corp, authorized applicators for Dow Corning takes up
the application work as per procedures and methodologies prescribed by Dow Corning.

4. Application of Sylgard HVIC+ at DGNP 132 kv SS
There are two incoming bays – Common Point and Naval Wharf,
and one outgoing feeder to DGNP Main receiving Station.
Line clear was obtained from Naval Wharf Incoming on the first day
of the coating, followed by Common Point.
With proper co-ordination with the APTRANSCO team and DGNP,
line clear was obtained from DGNP for few hours to complete the
coating on the equipments.
In all, 7 isolator switches, 12 CTs, 6 PTs, 4 CVTs, 3 Breaker and 6
LA’s were coated with Sylgard HVIC +. The total quantity applied
was 279 kgs.
The total activity was completed in 7 working days spread across
the month of July and August, including 4 days for the cleaning
activity, depending on the availability of L/C.
The following quantities are typically required for each 132 kv
equipments depending on their design and pollution conditions:
Isolator switches – 22 -28 kgs
CTs/PTs/CVTs – 3 -4.5 kgs
Breaker – 15 -22 kgs
LA – 2kg
Trafo Bushings – 3 kgs

5. Sylgard HVIC+ Pictures at DGNP 132 kv SS
From left to right, clockwise, Isolator switch and breaker in common point bay; a bird’s eye view of DGNP after completion of coating; Bus PTs and switch;
Naval wharf switch and breaker; DGNP outgoing feeder; and a row of CTs and PTs in the DGNP Feeder.

6. To know more:
Log into www.dowcorning.com/hvic
Mailto: satish@projectsalescorp.com
Call: 0891 2564393; 6666482
Fax: 0891 2590482
Dir: 098851 49412
Write to us at Project Sales Corp, 28 Founta Plaza, Suryabagh,
Visakhapatnam 530020, AP.