Current Transformer with 120A for Electronics Meter

Features
Adopted high pemeability core
High accuracy
Excellent linearity performance
Miniature size
Easy to install
DC immunity function

Specification

Dimension



Note:
The above parameter is only for reference as typical data, customer-made is subject to customers' request.

  
SHENZHEN CHUANGYIN TECHNOLOGY CO., LTD. 
( CY Group )
Certification: KEMA, ISO9001, UL, SGS, CE.
( Your reliable partner for CT,PT (up to 72.5KV) ,Cable accessories, Split core CT, Rogowski Coil , Latching Relay, Flx-core CT )

Arvin Q.
Business Development Executive
Mob:  +86 13925284622  
 
 
Address: 1st Floor, Building B, Jiada R&D Building, No.5 Songpingshan Rd.,  Shenzhen High-Tech Zones, Nanshan, Shenzhen, China, 
Post code:   518057
Tel:    +86 0755-86000716/ 86007806
Fax:    +86 0755-86000614
Web:  chuangyin.en.made-in-china.com
 Current transformers for Energy Meter 1.Technical Data(1) AC Tolerance    Below format is the range of phase error and ratio error at rated frequency and load: A. Ratio Error   It means the error while testing current. It caused by difference between actual current ratio and rated current ratio. It can be calculated in accordance with the following formulas.
Current Error = [ 100 ( Knls - Ip) / Ip ] %
Kn: Rated current ratio;
Ip: Actual primary current (unit: A)
Is: Actual secondary current while doing test by input Ip. (unit: A)B. Phase Error    It means the phase position difference between vector of primary current and vector of secondary current. Vector direction is subject to ideal current transformer whose phase error is zero. If secondary current vector is ahead of primary current vector, then phase error is positive number. Its unit is usually sub-arc or arc.
    Note: This definition is based on sinusoidal current
 (2) DC Tolerance    In normal condition, the power net is sinusoidal AC at loop, positive waves are symmetry. But in some special conditions, the circuit have DC, then positive and negative waves will not be symmetry. Common current transformer would be saturation under this condition, and the meter used this CT have large error, even can not work.So just DC Immunity CT can solve this problems.
    As following figure to test the DC error , 01 accuracy CT will be controlled within ±3.0%, 0.2 accuracy class CT will be controlled within ±6.0%.
 (3) Insulation Strength    Pri.-Sec.: AC4000V, 60s, 1mA(4) Insulation Resistance    Pri. Winding to Sec. Winding ≥ 1000MΩ (DC500V)
 2. PT (current type) used for power parameter transducer 
    HPT001-HPT006 is serial of current type Voltage transformer, widely utilized for power transmitter, power parameter transducer, etc. Typical application circuit diagrams as below shows. Max. Input and output current ratio is 1:1, Max. Input current is 10mA, max primary input voltage less than 1000V ( connect with current - limiting resistor ). Ratio error is ±0.1% and phase error is ±10, Loading Resistance is 0.
    Diagram 1, secondary loading resistance is 0 ( approx ). The measured input voltage (VIN) by current-limiting resistor (RIN) generated 0~2mA current through out PT. PT sense similar 0~2mA, through calculate amplifying, adjust the resistor value (R), resulting required output voltage.
Diagram 2, parallel connecting resistor (R) output circuit, Resistor (R) below 500Ω (max. Output voltage 1.5V). As the high burden, so the phase error is higher. But the linearity is basically unchanged.
 3. Typical Application of CT    With big output signal and high accuracy, current transformer is use in energy meter widely.(1) CT used for single phase energy meter (diagram 1) 
    Diagram 1, CT sampling from current signal, working principle is a shunt resistor, compare to current inductor (eg. Current Transformer).
    The resistor is advanced in low power consumption, which is more convenient for low current meter), Normally CT's output can connect ADE7755 through channel V1. V1 is fully differential voltage input channel, VIIP is input positive terminal , V1N is input negative terminal. Under special condition, the max differential signal of channel V1 is ±30mV (Similar as AGND),  for normal application, it is ±6.25mV. Resulting required output voltage.
    Diagram 2, parallel connecting resistor (R) output circuit, Resistor (R) below 500Ω (max. Output voltage 1.5V). As the high burden, so the phase error is higher. But he linearity is basically unchanged.(2) CT used for single phase energy meter (diagram 2) 
    Diagram 2, CT1, CT2, CT3 simple from A, B, C three phase current separately, inputting with three pairs of differential voltage, which are  IAP, IAN; IBP, IBN; ICP, ICN. The max voltage single ratio is ±0.5V among three. Current channel contains Programmable Gain Amplifier (PGA1), Amplifier' again is 1, 2 or 4.
     Except PGA function, channel V1 also applied fully signal scope selection function, when A/D shifting. As mentioned, Max input voltage scope is ±0.5V, by utilizing PGA1 number 3 & 4, set input voltage of ADS as ±0.5V, ±0.25V, ±0.125V, reference with ADC standard for certain condition.
Remark: Adjust Rf parameter to revise CT output signal.
 4. The graphs of CT material (core) and temperature dependence of phase error and ratio error.