RELIABILITY & EFFICIENCY OF

DISTRIBUTION TRANSFORMER

FROM WBSEDCL PERSPECTIVE

Since last 3 years, WBSEDCL is

procuring nearly 10,000 DTRs per year

on an average.

At present there are nearly 2.5 Lac

DTRs to cater consumer base of 1.65

crore in WBSEDCL system.

Present Scenario Of WBSEDCL System

10 KVA

16 KVA

25 KVA

50 KVA

63 KVA

100 KVA

150 KVA

160 KVA

200 KVA

250 KVA

315 KVA

400 KVA

500 KVA

630 KVA

1000 KVA

DTRs IN WBSEDCL SYSTEM

Subsequently, WBSEDCL started procuring

DTRs with dynamic loss figures (within IS

Limit) evaluated as per Loss- Capitalisation

formula.

Subsequently, with the Introduction of BEE

Star Rating, WBSEDCL started procuring

energy-efficient transformers with dynamic

loss figures evaluated on Loss- Capitalisation

formula.

Previously, WBSEDCL used to procure DTRs

with No-load Loss & Load-Loss figures as per

relevant IS.

Now, with the enactment of Quality Control

order (BIS Marking), WBSEDCL has just started

procuring BIS compliant Transformers with

Level-2 Loss figure without Loss Capitalization.

WBSEDCL is also procuring DTRs from BIS

certified manufacturers having certification of

BIS Level-2.

Since, last 6 years, WBSEDCL has introduced

testing of DTR after delivery at store.

ALLOWABLE LIMIT OF OIL AND WINDING

TEMPERATURE RISE

Before Now

As per IS 2026 As per IS 1180 Part-I of 2014

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Preventive measures to arrest failure rate of DTR

1. Sizing of DTR – Twice the calculated Load. This will

reduce the Total Owning Cost of DTR.

2. Avoid single phasing of DTR as far as practicable.

3. Installation of RMU in Urban area at HT side for

better protection of DTR.

4. Periodical Health Checkup of DTR

5. Ensuring better DTR quality by procuring low loss

DTR with low temp. rise

DTR Meter

DTR

As part of energy management scheme WBSEDCL has

started installing DTR meters on each and every DTR

in a phased manner with provision of remote metering

in urban areas.

This facility will be extended to DTRs installed in

rural area through DDUGJY Project

Statistics Of DTR Meter Installed – Urban Area

Total DTR Meter Installed=43502

Reading Through Remote

Sensing=22894

Manual (By LPR)

Reading=20608

As a preventive measure, WBSEDCL is

conducting the following periodical health

checkup of DTRs

Load Balancing from DTR meter data &

physical measurement.

Decision for Augmentation of DTR size

from DTR meter data.

Oil Condition and level of Oil from

Health Check – up data.

Strengthening of DTR Earthing where

required.

Terminal Connection and Protective

Device Checking