Current transformers TZRL (ТЗРЛ)

Current transformers TZRL (ТЗРЛ)

Zero-phase-sequence current transformer TZRLDescription

The transformers are intended for powering relay protection circuits from grounding separate conductors of three phase cable through transformation of null string currents. The transformer in fixed on the cable with diameter 70, 100, 125 and 200 mm.
The transformers are manufactured in compliance with the standard requirements of GOST 15150 in climatic version "У" (moderate) location category 3 and are intended for operation under the following operating conditions:

  • altitude above sea level is not higher than 1000 m;
  • ambient air temperature during operation is from minus 45 °C to plus 50 °C;
  • ambient air humidity is 98% at 25 °C;
  • the environment should be non-explosive, without corrosive steams in concentrations that are likely to destroy metal or insulation (atmosphere type II as to GOST 15150);
  • mounting in any position. 

Table 1. Technical data

Parameter

Value

Rated frequency, Hz

50 or 60

Rated voltage, kV

0,66

One second thermal stability current on secondary winding, A

140

One-minute test voltage of industrial frequency, kV

3

Table 2. Dimensions

Design version

Transformation coefficient

Dimensions, mm

Mass. kg

h

B

H

H1

H2

D

L1

L

TZRL-70

30/1

14

85

172

62

85

72

100

213

6,4

TZRL-100

30/1

21

60

214

72

102

102

125

250

7,5

TZRL-125

30/1

21

80

232

88

112

127

125

270

8,4

TZRL-200

60/1

27

60

330

130

158

205

180

360

9,8

Table 3.

Relay type

Relay scale, A

Preset latching current, A

Protection sensetivity (of primary current, A), no more

at the operation with one transformer

at the operation with serial connection of two transformers

at the operation with parallel connection of two transformers

РТ-140/0,2
РТЗ-51

0,1–0,2
0,02–0,1

0,1
0,03

25
3

30
4

45
4,5

General view of transformer (drawing)

Transformers TZRL intended for operating as protective transformers

Table 4. Technical data of transformers TZRL intended for protection (with accuracy class 10P)

Parameter Value
TZRL-200 TZRL-125 TZRL-100 TZRL-70
Rated voltage, kV 0.66
AC current frequency, Hz 50 or 60
Rated primary current, A* 600; 750; 800; 1000; 1200; 1500; 2000
Rated secondary current, A 1
Number of secondary windings 1
Rated secondary burden, VA at cos φ = 0.8 (active-inductive) 3-30
Accuracy class 10P
One-second thermal current, A, no less 50
Short-circuit current ratio of secondary winding at rated burden of 30 VA 5 7 5 9

* Should be specified in the order

Zero-phase sequence transformers TZRL intended for operating in connection with microprocessing protection similar to "SEPAM"

Table 5.

Parameter Value
TZRL-200; TZRL-125; TZRL-100; TZRL-70
Rated voltage, kV 0.66
AC current frequency, Hz 50 or 60
Rated primary current, A, no more than 100
Transformer ratio 470/1
One-second thermal current, A, no less than 20

Table 6.

Type of transformer Dimensions, mm Weight, kg, max
d h1 H L2 L1 L
TZRL-200 205 60 330 127 180 360 10.8
TZRL-125 125 80 227 85 125 270 10.4
TZRL-100 100 75 205 70 125 255 6.5
TZRL-70 70 95 172 55 100 213 7.4

General view of transformer (drawing)