EARTHING TRANSFORMERS - ETR

I EARTHING TRANSFORMERS - ETR ETR earthing transformers are used to create an artificial neutral in distribution electric networks:

Fig.1 earthing transfomer in an electric distribution network Typical parameters of ETR earthing transformers are: - networks of 6, 10, 15, 20, 35 kV - rated power from 200 to 5000 kVA - connection group Zn, ZNyn 11 or other

variants based on customer´s wishes Typical ETR earthing transformers are placed in a corrugated wall tank and are hermetically sealed. Smaller corrugated wall tanks are hot dip galvanized and painted (if required). Typical colour shade is RAL 7033. Larger tanks are painted with zinc paint.

Fig.2 ETR earthing transfomer – hermetically sealed Alternatively larger ETR earthing transformers can be placed in a tank equipped with DIN radiators, an expansion tank and an air breather.

Radiators are hot dip galvanized and painted, the tanks are provided with a zinc layer using spray zinc metallizing method. The expansion tank is equipped with an oil level gauge.

Fig.3 ETR earthing transfomer – tank with radiators Bushings are of various types: porcelain DIN or EN bushings, Euromold or Connex cable connectors. The transfomer oil temperature is monitored by a thermometer. Typical transformer oil used in ETR earthing transformers is Shell Diala S2. Lugs determined for lifting the complete transformer are placed on the cover or on tank walls under the cover (larger earthing transformers). ZNyn earthing transformers are equipped with an off-load tap changer purchased from one of the most prestigious companies. ETR earthing transformers are equipped with an oil drain valve placed at the bottom of a transformer. If required the transformers can be equipped with bi-directional wheels.

EGE, spol. s r.o. Novohradská 34 37008 České Budějovice Czech Republic Tel.: 00420 38 77 64 412, Fax: 00420 38 77 64 603, e-mail: elaobch@ege.cz, www.ege.cz

ELA O 162.2 EN

EGE, spol. s r.o. Novohradská 34 37008 České Budějovice Czech Republic Tel.: 00420 38 77 64 412, Fax: 00420 38 77 64 603, e-mail: elaobch@ege.cz, www.ege.cz

ELA O 162.2 EN

EARTHING TRANSFORMERS - ETR

Table.1 – examples of ETR earthing transformers: - ZN connection group - continuous operation duty - corrugated tank - hermetic design

RATED POWER L - length W- width H - height

ТYPE [кVА] [mm] [mm] [mm] ETR0200 200 1350 770 1200 ETR0315 315 1360 770 1400 ETR0500 500 1500 950 1550 ETR0800 800 1900 1300 1550 ETR1000 1250 2000 1300 1700 ETR2500 2500 2000 1300 1900

Net

wor

k

rate

d vo

ltage

10

,11

kV

ETR4200 4200 2335 1320 2100

EGE, spol. s r.o. Novohradská 34

370 08 České Bud ějovice Czech Republic

www.ege.cz

Tel.: 00420 38 77 64 412 Fax.: 00420 38 77 64 603 E-mail: elaobch@ege.cz