Knopp Incorporated
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Type KC-1500 Current Transformer
Test System

Functional Description and Specifications

A.    General

  1. The test system shall be able to check the accuracy of instrument transformers having primary ranges from 5 to 1500 amperes.

  2. The test system shall include a built-in, microprocessor-controlled, automatic, autoranging comparator.

  3. The test system shall incorporate protective circuitry to ensure the safety of the operator, the test system, and the transformer-under-test.

  4. The test system shall be composed of two easily transportable pieces to allow for field testing of transformers.

  5. The accuracy and calibration of the precision transformer shall be traceable to the National Institute of Standards and Technology.

  6. The test system shall be suitable for 60 Hz. operation.

B. Test Ranges and Burdens

  1. The following primary ranges shall be provided:

5, 10, 15, 20, 25, 30, 40, 50, 75, 100, 150, 200, 300, 400, 500, 600, 800, 1000, 1200 and 1500 amperes.

  1. 400% tests shall be able to be performed on all ranges up to, and including, 300 amperes.

  2. 200% tests shall be able to be performed on all ranges up to, and including, 600 amperes.

  3. The secondary current shall be 5 amperes.

  4. Provisions shall be made for connection of external burdens.

C. Comparator

  1. The comparator shall be dedicated to the test system. It shall only be capable of testing current transformers.

  2. The comparator shall be automatic and autoranging, to provide minimum measurement time. Measurements shall be completed within five seconds of adjusting the test current.

  3. The comparator shall digitally display test current and test results. Test results shall consist of ratio error [in Percent or Ratio Correction Factor (RCF)] and phase error (in minutes or milliradians).

  4. The comparator shall calculate and digitally display the best accuracy class for which the transformer-under-test qualifies.

  5. The comparator shall include protective circuitry which senses error conditions, such as wrong ratio or wrong polarity, and then automatically removes power from the test system loading circuitry.

  6. The comparator shall offer printer or RS-232C (serial) test result output options.

D. System Accuracy

  1. The combined error of the precision current transformer and the transformer comparator shall be no greater than 0.025% on ratio and 2 minutes on phase angle at 100% full load current.

E. Self Check

  1. The calibration of the precision transformer shall be able to be periodically checked by the One-to-One method, whereby the ratio and phase angle performance can be quickly and accurately checked without the use of an external reference standard.

F. Input Power Requirements

  1. The test system shall operate off of 120 volt, single-phase, service at a nominal 15 amperes.

G. Weight and Dimensions

  1. The test system shall be divided into two consoles.

  2. The approximate weight of console 1 shall be 55 lbs. (24.9 kg.).

  3. The approximate weight of console 2 shall be 95 lbs. (43.1 kg.).

  4. Console 1 shall measure approximately 6.00 in. (15.2 cm.) High, 29.20 in. (74.2 cm.) Wide, and 16.0 in. (40.6 cm.) Deep.

  5. Console 2 shall measure approximately 9.50 in. (24.1 cm.) High, 28.20 in. (71.6 cm.) Wide, and 24.69 in. (62.7 cm.) Deep.

H. Instruction Manual and Drawings

  1. An instruction manual shall be furnished with the system.

  2. A schematic diagram of the test system circuitry shall be included with the system.

I. Warranty and Service

  1. A full one year parts and labor warranty shall be furnished with the system.

  2. A toll-free telephone line shall be made available for troubleshooting and repair purposes.

  3. All replacement parts shipped under warranty shall be sent via overnight express carrier at no extra charge.

J. Options

  1. It shall be possible to purchase an extended warranty.

  2. It shall be possible to purchase a cable and hardware kit for connecting the transformers-under-test.

  3. It shall be possible to purchase a printer for printing test results.

  4. It shall be possible to purchase American National Standards Institute (ANSI) burdens for use with the system. The burdens shall have the following characteristics:

  1. The following ANSI burdens shall be available:

B-0.1, B-0.2, B-0.5, B-0.9, B-1, B-1.8, B-2, B-4, and B-8.

  1. These burdens shall be passive burdens, and shall be very stable and highly accurate (the resistive and inductive component values shall be accurate to within 1%).

  2. Burdens up to, and including, B-1.8 shall be rated for 400% testing, while the remaining burdens (B-2, B-4, and B-8) shall be rated for 200% testing.



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