CAB – handheld breaker and timer analyser

 Compact and ergonomic design – only 1,6 kg (3.5 lbs)
 Simple and easy to operate
 Battery operation for up to 8 hours
 Timing and coil current measurement
 Coil control (built-in) for OPEN and CLOSE coil
 Graphical results for quick interpretation
 Touch screen color display 145 mm (5.7 in)
 On-site analysis of test results

(overlay up to 4 records in graphical form)

Image: DV Power CAT-H handheld circuit breaker analyser and timer with waveform display, keypad, and DC clamp, DC voltage and MC inputs.

Description

Handheld Circuit Breaker Analyzer & Timer CATH is a digital instrument for circuit breakers condition assessment. CAT-H records graphs of both, open and close coil currents, timing of main arcing contacts, DC substation battery voltage. The timing channels record closing and opening of the main contacts and can also measure the resistance value of the pre-insertion resistors (if present in the circuit breaker).

CAT-H provides an easy selection of different operating modes:

Open (O)

The circuit breaker operation can be initiated in different ways (for instance from a control room, by a local switch or externally by a testing device) depending on a testing condition. The several time measurement triggers are available to record a measurement in a various testing condition:

Coil control channel
DC current clamp channel
DC voltage channel

CAT-H is a powerful diagnostic tool for recording and analyzing:

Close (C)
Trip free (CO)
Reclose (O-C)
Close-Open (C-O)
Open-Close-Open (O-C-O)

Multiple operations, such as Open-Close and Open-Close-Open, can be initiated by using a predefined delay time or by sensing a breaker’s contact position.

Main arcing contacts operation
Trip/Close coils operation
Auxiliary contact operation
DC supply voltage
Integrity of control circuit wiring

CAT-H displays numerical and graphical results (it can overlay up to 4 records in graphical form). This enables quick onsite analysis of potential defects by comparing the obtained test results.

Features

Image: Numbered views of a circuit breaker analyser and timer: front panel with screen showing test curves, numeric keypad and function keys, plus top and bottom connector panels.

1 - Coil supply input

Voltage supply input for coil control.

2 -Coil control outputs

Used for operating the circuit breaker’s OPEN and CLOSE coil

3 - DC current clamp input

Used for a DC coil current recording and measurement.

4 - DC voltage channel input

Used for a voltage measurement of an analog signal.

5 - Main contacts input for offline measurement

Used for timing of the main and pre-insertion resistor contacts, and for the resistance measurement of the pre-insertion resistors.

6 - Touchscreen display

Touchscreen color display 5.7 in

7 - Soft keys

Used for selecting preferred (test) settings (options/menus) as an alternative to touchscreen.

8 - Alphanumeric keypad

Used for entering breaker data, test data and control functions.

9 - Power ON/OFF indicator

Indicates if the instrument is turned ON/OFF.

10 - READY button

Prepares the instrument for the start of the test.

11 - Power ON/OFF button

Used for turning ON/OFF the instrument turning.

12 - DC power supply

12 V DC, 3 A

DC adapter 85-264 V AC (47-63 Hz) / 12 V DC

13 - Flash drive

Used for a direct download of test results on a USB memory stick.

14 - PC communication

USB interface for PC.

Application

The list of the instrument applications includes:

Timing measurement of up to 3 main contacts (1 break per phase) including pre-insertion resistors (if present in the circuit breaker) and auxiliary contact.
Resistance measurement of the pre-insertion resistors (if present in the circuit breaker).
Main contacts bounce time measurement.
Pre-trigger time measurement.
Evaluation of synchronization between the circuit breaker poles.
A measurement and graphical display of the coil currents.
Coil control (built-in) for actuation of circuit breaker’s OPEN and CLOSE coil.
Evaluating the state of the substation’s battery (or other types of analog signals that may be relevant) by presenting the voltage value numerically and graphically.

Timing Measurement

Timing measurement of the mechanical operations is one of the most important tests to determine real condition of the circuit breaker. Timing measurement tests fulfill all the requirements stipulated in IEC 62271-100 and ANSI C37.09.

In three-phase systems, not only the contacts in a single pole have to operate simultaneously, but all poles must also operate at the same time. All contacts must be synchronized, within a certain tolerance limit.

Synchronization between the circuit breaker poles during opening shall not exceed 1/6 of the rated frequency cycle (3,33 ms at 50 Hz; 2,78 ms at 60 Hz) and during closing shall not exceed 1/4 of the rated frequency cycle, as well (5,0 ms at 50 Hz; 4,17 ms at 60 Hz).

Simultaneous measurements within a single phase are important in situations where a number of contacts are connected in series.

The CAT-H can be used for measurement of the main arcing contact operating times when the circuit breaker is isolated from the power grid or is being tested at another location such as the manufacturer’s premises or a maintenance workshop. When making test connections circuit breaker needs to be is disconnected or separated from its circuit on both sides of the breaker in accordance with the national safety regulations. The circuit breaker needs to be properly grounded to a protective ground.

Auxiliary contacts are mechanically driven by the operating mechanism and are used for control and indication of the main contacts state. There are no general requirements related to timing measurement of auxiliary contacts, described in IEC^® and ANSI^®standards. However, in order to assess conditions of high-voltage circuit breakers, it is important to check their operation.

Image: Figure 1. CAT-H connection to live tank circuit breaker with one breaking element per phase

Image: Figure 2. CAT-H connection to dead tank circuit breaker with one breaking element per phase

Coil current measurement

The IEC 62271-100 standard states that it is desirable to record the coil currents waveform, since it provides information about coils’ condition (e.g. increased friction of the plungers, burned insulation, short-circuited part of the winding), the latch for release of the operating mechanism (e.g. increased friction) and the operating mechanism (e.g. if there is reduced operating mechanism speed that can be seen based on the opening time of auxiliary contacts).

When the opening or closing command is initiated, the coil is energized (point 1) and the current rises causing a magnetic field to apply a force on the iron plunger. When the force on the plunger exceeds the retaining force, the plunger begins to move (point 2). The motion of the iron plunger induces an EMF in the coil, effectively reducing the current.

The combined mass of the plunger and the latch continue to move at a reduced velocity causing a further reduction in the coil current (points 2 to 3)

until it hits a buffer bringing it to a rest (point 3). If the current values at points 2 and 3 are higher than specified and the time at point 3 is longer than specified, it may indicate a friction of the plunger and latch. With the plunger at rest, the current increases to the saturation level (DC current which is proportional to the coil resistance, point 4). If the current value from point 4 to point 5 deviates from specific it may indicate a burned insulation or short-circuited part of the winding of coil. Meanwhile, the latch unlocks operating mechanism, releasing the stored energy to open the main breaker contacts. Typically, after a short delay the auxiliary contacts open, disconnecting the opening coil from the control voltage (point 5). As the coil is deenergized the current drops quickly to zero in accordance with the coil inductance (point 6). Longer time than specified at points 5 and 6 may indicate auxiliary contact malfunction or insufficient driving energy of the operating mechanism.

Image: Figure 3. Coil current specific points and measurement parameters

DV-Win software

DV-Win software provides acquisition and analysis of the test results. Graphical presentation of a variety of measurements and timing test results uses cursors and powerful zoom functions for detailed analysis. Colors, grids, scales and positioning of the test data are all controlled by the user.

DV-Win supports an automatic unit conversion (e.g. cycles to seconds or mm to inches). The test records can be exported in .cath file format for further analysis.

Image: Breaker analyser software screen with graphs of voltage, coil current and main contact states against time, plus tables of numerical results such as opening times, synchronisation and coil currents.

Downloading the test results from the CAT-H to PC
Selecting the measurement points and
intervals using the two cursors
Acquisition and analysis of the test results
The test results can be viewed, edited, saved, printed and exported
Zoom and pan graph feature
Customized configuration of the test result graphs
Viewing and overlaying several graphs, for an easy test result comparison

Technical data

Current measurement

Main contact inputs

Number of contact inputs: 3 (3 x 1), 1 per phase
Each channel detects Main contacts
Closed ≤ 10 Ω
Resistor contacts range 10 Ω to 5 kΩ
Open ≥ 5 kΩ Open circuit voltage: 20 V DC ±20% Short circuit current 50 mA

Time measurement

Time measurement resolution:

0,05 ms to 10 ms depending on test duration (sampling rate up to 20 kHz)

Time accuracy: 0,05% of the reading ± resolution

Breaker operation

Close (C)
Open (O)
Close-Trip (C-O)
Trip-Close (O-C)
Trip-Close-Trip (O-C-O)

DC Current Clamps

Nominal current: 300 ARMS or 450 A DCPK
Measuring ranges: 30/300 A
Frequency range: DC to 20 kHz (-3 dB)

DC Voltage Measurement

Range: ±300 V
Typical accuracy: ±0,5% RDG ±0,5% FS
Guaranteed accuracy: ±1% RDG ±1% FS

Coil driver

Number of channels: 2 (Trip and Close coil)
Driver characteristics: 300 V DC max, 35 A DC max
Electronic drivers provide superior timing control
Overcurrent and overvoltage protection
Coil supply input: 300 V DC max, 35 A DC max
Current measurement for Trip and Close coil, 2 channels, Hall-Effect sensor
Range ±35 A DC to 5 kHz
Accuracy ± (0,5 % rdg + 0,1 % FS)
Graphic presentation: currents waveform is displayed with a resolution of 0,1 ms

Handset and inline power supply

12 V DC, 3 A
Input: 90 – 264 V AC, 50/60 Hz

Internal battery supply

2 x 3,7 V, 2900 mAh rechargeable Li-ion battery
8 hours under normal usage

Display

Touch screen color display 145 mm (5.7 in)

Applicable standards

Safety:

Low Voltage Directive: Directive 2014/35/EU (CE conform) Applicable standards, for a class I instrument, pollution degree 2, Installation category II: IEC EN 61010-1

Electromagnetic Compatibility: Directive 2014/30/EU (CE conform) Applicable standard: EN 61326-1
CAN/CSA-C22.2 No. 61010-1

Environmental conditions

Operating temperature:
10 ºC to + 55 ºC / 14 ºF to +131 ºF
Storage & transportation:
40 ºC to + 70ºC / -40 ºF to +158 ºF
Humidity 5 % - 95 % relative humidity, non condensing

Dimensions and weight

Dimensions (L x W x H):
310 x 170 x 58 mm / 12.21 x 6.69 x 2.28 in
Weight:
1,6 kg / 3.5 lbs

Warranty

3 years

All specifications herein are valid at ambient temperature of + 25 °C and recommended accessories. Specifications are subject to change without notice.

Accessories

Image: Set of colour-coded voltage leads with crocodile clips.

Image: Black cable harness with several crocodile clips.

Image: Pair of red and black test leads with banana plugs.

Image: Current clamp probe with its connection cable.

Image: Accessory headings: main contact cables 8 m (26.3 ft) with alligator clamps; main contacts connection 3 × 1 m and ground 2 m cable; voltage sense cable set 2 × 5 m, 2.5 mm² with banana plugs; current clamp 30/300 A with 5 m extension.

Image: Coiled grey sensor cable with connectors.