10KV Medium Voltage Casting insullation current instrument
transformer
Theory
Instrument transformers are high accuracy class electrical devices
used to isolate or transform voltage or current levels. The most
common usage of instrument transformers is to operate instruments
or metering from high voltage or high current circuits, safely
isolating secondary control circuitry from the high voltages or
currents. The primary winding of the transformer is connected to
the high voltage or high current circuit, and the meter or relay is
connected to the secondary circuit.
Instrument transformers may also be used as an isolation
transformer so that secondary quantities may be used in phase
shifting without affecting other primary connected devices.
Current transformers (CT) are a series connected type of instrument
transformer. They are designed to present negligible load to the
supply being measured and have an accurate current ratio and phase
relationship to enable accurate secondary connected metering.
Current transformers are often constructed by passing a single
primary turn (either an insulated cable or an uninsulated bus bar)
through a well-insulated toroidal core wrapped with many turns of
wire. This affords easy implementation on high voltage bushings of
grid transformers and other devices by installing the secondary
turn core inside high-voltage bushing insulators and using the
pass-through conductor as a single turn primary.
Applications
The LZZW-10Q outdoor current instrument transformers are fully
enclosed and cast in epoxy resin. Instrument transformer is
equipped with one core and coil assembly rated for measurement and
protection, and then output multi ratio. The current transformers
are designed for electric power systems of 50Hz/60Hz rated
frequency and 35kV rated voltage. They are used for outdoor
mounting. The performances of the products meet standards
IEC60044-1, IEC61869-2 and ANSI/IEEE C57.13. The products are
applied to metering electric energy, voltage controlling and relay
protection.
1. Measurement current & voltage for energy meter and power meter
2. Supply protection current signal for microcomputer protection
relay set
Features
New magnetic material is taken to be the core of the current
instrument transformer, which has high magnetic permeability, low
saturation magnetization and good stability. Therefore, the
measuring accuracy is higher and the instrument security factor is
lower. Since the high quality silicon processed by advanced
technology is taken to be the core of the protection windings,
which assured the accuracy limit factor is higher.
The semicircular ring core and secondary windings are vacuum poured
by high quality epoxide resin in the fire retardant plastic casing,
which has the characteristic of moisture proof, stable performance
and dispensing with maintenance.Small size, light weight, small
footprint, fixed in the ring network switchgear cable.The cable can
cross the current transformer through its internal poles quickly
and uniformly.
The Cast Resin Straight-Through Current Transformer can be divided
several kinds according to the various current ratio, accuracy and
rated loads. The specific parameters are showed in the
corresponding to each model parameter tables.
High precision 0.2s
Designed for 30years lifes
Good Stability in 33kv power line
Big burden.
Multi ratio CT
PARAMETERS
Rated primary current
(A) | Ith/ls
(KA r.m.s.) | Idyn
(KA peak) |
Accuracy class
combination | Rated secondary output(VA) | Surface creepage distance
(mm) | Wt
(KG) | | 0.2(S) 0.5S | 0.5 | 5P10 | 5P15 | 5P20 | | 20-40 | 4 | 10 | 0.2(S)/5p
0.5(S)/5p | 10 | 15 | 20 | 15 | 10 | 460 | 23 | | 30-60 | 6 | 15 | | 40-75 | 7.5 | 18.8 | | 50-100 | 10 | 25 | | 75-150 | 15 | 37.5 | | 100-200 | 20 | 50 | | 150-300 | 30 | 75 | | 200-400 | 40 | 100 | | 300-600 | 60 | 130 | | 400-800 | 80 | 160 | | 500-1000 | | 600-1200 | 100 | 160 | | 750-1500 |
|
ORDERING INFORMATION
Be sure to the type, current ratio, accuracy class, rated load and
use of the products when you plan to make a order. Special
specifications could be customized.All kinds of different
specifications and parameters current transformers can be made
according to your needs.
P1, P2 is primary polarity terminal, S1, S2 is secondary polarity
terminal.
P2, S2 is homonymous terminals (subtractive polarity).
