CURRENT TRANSFORMERS type IMZ 24
Catalogue card
APPLICATION The cast – resin insulated, single – phase, supporting current transformers type IMZ 24 are intended for supplying measuring instr ments and protective circuits of electrical power devices with maximum operating voltage of the power networkup to 24kV andfrequency50 Hz.The range of rated primary currents: 5 ÷ 1500A and 2 × 15 ÷ 2 × 600A. Version with one, two or three cores.
CHARACTERISTICS – small overall dimensions, – all o f mounting dimensions enable the interchangeability of transformers of this type with other transformers manufacturedby well – known firms, – thereliability of operation.
OPERATING CONDITIONS The current transformers type IMZ 24 are designed for operation in indoor equipment, in temperate and tropical climate conditions,and in aggressive environmental conditions.Thanks to the increased impulse test voltage strength and to the increased rated thermal strength the current transformers type IMZ 24 are able to operate at altitudes up to 2600 m above sea level. Long – duration thermal current and limits of deviations of transformers in class of accuracy 0,5 correspond to extended current range for 120% × Ipn. The lowest permissible temperature during transportation and storage amounts to 218 K (-55°C). The current transformers type IMZ 24 are designed for operation at temperatures from 268 K (-5°C)to 313 K (+40°C).
DESIGN AND PRINCIPLE OF OPERATION The cast – resin insulated cur rent transformers type IMZ 24 are single – phase, low power transformers, operating in quasi short – circuit conditions, transforming the primary current flowing through the high voltage circuit to the secondary current at low potential with theaccuracy according to their class. The basic structural components o f the current transformers are:prima ry winding, secondary winding or windings, magnetic core and steel base.The pr imary winding is cast in epoxy – resin mixture.The resinous casting constitutes the main insulation of the transformer. The secondary windings, wound on the insulating spools, are placed together with the magnetic cores in thewindow of theresinous casting.The steel base is screwed down to theresinous casting. There is the terminal box in the base, in which there are installed the terminal plates with the leads of secondary windings connected to them. The grounding of no matter which of the terminals of seco ndary winding is made by screwingin a bolt, which is present in a smallfoil bag placed in the terminal box. We deliver, on Customer’s request, the cover for current transformers with two and three cores, which enables the sealingof theterminals of measuring windingsonly.
COMPLIANCE WITH STANDARDS – PN–IEC 60044-1 – IEC 60044-1 – VDE 0414/12.70
THE EXAMPLE OF ORDER The current transformer type IMZ 24, 2 ×100/5/5 A/A/A, Ith = 200 × Ipn I core: 10 VA, class 0,5; FS 10 II core: 5 VA,10 P 10
WARRANTY The factory warranty is twenty four months since the day of putting the apparatus into operation, but not longer than thirty sixmonths since thedate of purchase.
TECHNICAL DATA
Type
IMZ 24
Maximum permissible voltage of transformer
Rated test votage of insulation lightning
Rated frequency
Um
power frequency Up
Upp
kV
kV
24
50
Maximum short-time current
Rated short-time dynamic current
dynamic
f n
thermal (1- sec.) Ith max
Idyn max
Idyn
kV
Hz
kA
kA
kA
125
50
60
150
2,5 x I th
The approximate mass of current transformer type IMZ 24 amounts to 33 kg. 2
ABB
Minimum installation distances for current transformers type IMZ 24 in consideration of test voltage
ABB
4
DIMENSIONAL DRAWING
5
0 0 2.
2
0 n io t a ci l b u P
ABB Sp. z o.o. Power Technologies Division ul. Leszno 59 06-300 Przasnysz, Poland Phone: (+48 22) 51 52 838, 51 52 831 (+48 29) 75 33 233, 75 33 240 Fax: +48 22 51 52 659, +48 29 75 33 327 www.abb.com
