Vanguard RFD-200 S2 User Manual

RFD-200 S2

PORTABLE RELAY TEST SET

USER’S MANUAL

Vanguard Instruments Company, Inc.

1520 S. Hellman Ave.
Ontario, California 91761, USA

TEL: [phone]
FAX: [phone]

September 2009

Revision 2

RFD-200 S2 USER’S MANUAL REV 2

SAFETY SUMMARY

FOLLOW EXACT OPERATING PROCEDURES

Any deviation from the procedures described in this User’s Manual may create one or more
safety hazards, may damage the RFD-200 S2, or cause errors in the test results. Vanguard
Instruments Company, Inc. assumes no liability for unsafe or improper use of the RFD-200 S2.

All safety precautions provided in this manual must be observed during all phases of testing
including test preparation, test lead connection, actual testing, and test lead disconnection.

SAFETY WARNINGS AND CAUTIONS

Only trained operators shall use this device. All devices under test shall be off-line and fully
isolated.

DO NOT MODIFY TEST EQUIPMENT

To avoid the risk of introducing additional or unknown hazards, do not install substitute parts or
perform any unauthorized modification to any RFD-200 S2 test unit. To ensure that all designed
safety features are maintained, it is highly recommended that repairs be performed only by
Vanguard Instruments Company factory personnel or by an authorized repair service provider.
Unauthorized modifications can cause safety hazards and will void the manufacturer’s
warranty.

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TABLE OF CONTENTS

CONVENTIONS USED IN THIS DOCUMENT ..................................................................................... 1

1.0 INTRODUCTION .................................................................................................................. .. 2

1.1 General Description and Features ................................................................................... 2

1.2 Furnished Accessories ...................................................................................................... 3

1.3 RFD-200 S2 Technical Specifications ................................................................................ 4

1.4 Controls and Indicators .................................................................................................... 6

2.0 FUNCTIONAL DESCRIPTION ................................................................................................. 8

2.1 RFD-200 S2 Auxiliary Power Supply ................................................................................. 8

2.2 RFD-200 S2 Current and Voltage Sources ........................................................................ 8

2.3 Control Switches .............................................................................................................. 9

2.3.1. Voltage and Current Source Controls ....................................................................... 9

2.3.2. LCD Contrast Control ................................................................................................ 9

2.4 Timer Start and Timer Stop Inputs ................................................................................. 10

2.5 RFD-200 S2 Power Resistors .......................................................................................... 10

2.6 RFD-200 S2 External Voltage Input ................................................................................ 11

2.7 RFD-200 S2 External Current Input ................................................................................ 11

3.0 OPERATING PROCEDURES ................................................................................................. 12

3.1 Setting the Voltage or Current Source ........................................................................... 12

3.2 Setting the RFD-200 S2 for a Time Delay Test ............................................................... 13

3.3 Using the RFD-200 S2’s Timer to Test Circuit Breaker Response Time ......................... 16

3.4 Using the RFD-200 S2’s Timer in Single Input Mode ..................................................... 18

3.5 Using the RFD-200 S2 to Plot a Current Transformer Excitation Curve ........................ 20

3.6 Using the RFD-200 S2 to Measure CT Primary and Secondary Currents ....................... 22

LIST OF TABLES

Table 1. RFD-200 S2 Technical Specifications ................................................................................. 4

Table 2. RFD-200 S2 Output Specifications .................................................................................... 5

Table 3. RFD-200 S2 Timing Accuracy ............................................................................................. 5

Table 4. Functional Descriptions of MCCB-250 Controls and Indicators ........................................ 7

LIST OF FIGURES

Figure 1. RFD-200 S2 Controls and Indicators ................................................................................ 6

Figure 2. Typical Over Current Relay Connection ......................................................................... 15

Figure 3. Typical Circuit Breaker Timing Connection .................................................................... 17

Figure 4. Typical CT Excitation Test Connection ........................................................................... 21

Figure 5. Typical CT Turns Ratio Test Connection ......................................................................... 24

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RFD-200 S2 USER’S MANUAL REV 2

CONVENTIONS USED IN THIS DOCUMENT

This document uses the following conventions:

• A key, switch, input, or knob on the RFD-200 S2 is indicated as [KEY], [SWITCH],

[INPUT], [KNOB]

• RFD-200 S2 LCD screen output is shown as:

0mS 0.0CY
V Mtr: -0.003 V
Int I: 0.080 A
Ext I: -0.001A

• Warning messages are indicated as:

WARNING

• Important notes are indicated as:

.

Warning message

Note details

NOTE

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1.0 INTRODUCTION

1.1 General Description and Features

The RFD-200 S2 is a portable relay test set that delivers performance verification testing of
electromechanical, electronic, and microprocessor-based protective relays in their operating
installations. The RFD-200 S2 is a rugged test set suitable for testing a variety of protection
relays operated in both indoor and outdoor environments. The unit’s ergonomic design and
intuitive control panel layout make it ideal for first-time users who have little or no training.

AC Current Source

An AC current source with three outputs (10A, 40A, and 100A) provides test current to relays.
The current source output can be programmed to synchronize with the RFD-200 S2’s timer.
After a test is completed, the test current is turned off and the current reading is latched and
displayed on the LCD screen. This feature reduces the possibility of overheating the relay coils.

Built-in Power Resistors

The RFD-200 S2 features five built-in power resistors for fine current adjustment.

AC Voltage Source

An AC voltage source is available for testing relays up to 250 Vac. The AC voltage source output
can be programmed to synchronize with the RFD-200 S2’s timer.

DC Voltage Source

A 0 – 300 Vdc voltage source is also available for testing purposes.

Built-in Digital Timer

The RFD-200 S2’s digital timer features independent start and stop trigger inputs designed to
measure the time between event transitions and to display the elapsed time in both
milliseconds and cycles. The RFD-200 S2’s timer has three different trigger input modes –
Internal Trigger, Dry-Contact, or Wet-Contact. In Internal Trigger Mode, the timer can start or
stop by sensing the application or removal of the unit’s voltage or current source. In Dry­Contact Mode, the timer can be triggered by detecting a change in state of the dry-contact
input. Similarly, in Wet-Contact Mode, it can be triggered by detecting a change in state of the
voltage input.

Auxiliary AC/DC Power Supplies

The RFD-200 S2 provides three power supplies (24 Vdc, 124 Vdc and 240 Vac) for powering
solid-state or microprocessor-based relays.

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RFD-200 S2 USER’S MANUAL REV 2

RFD-200 S2 Ampere Meters

The test current is displayed on the unit’s back-lit LCD screen that is viewable in both bright
sunlight and low-light levels. The current measuring range is from 0.00 to 250 A. A second
ampere meter is also available and can be used to read an external current input. The external
current input is rated at 6A max and is protected by a circuit-breaker.

RFD-200 S2 Volt Meter

One volt meter input (0 to 600 V input range) is available on the RFD-200 S2. This input uses the
true RMS for AC measurement method.

1.2 Furnished Accessories

The MCCB-250 comes furnished with the following:

• One power cord

• One set of 8-foot current cables

• One 8-foot timer start cables

• One 8-foot timer stop cables

• One 8-foot voltage cables

• One ground cable

• One cable carrying duffel bag

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1.3 RFD-200 S2 Technical Specifications

Table 1. RFD-200 S2 Technical Specifications

TYPE Portable relay test set

INPUT POWER 100 – 120 Vac or 200 – 240 Vac (factory pre-set), 50/60 Hz

PHYSICAL SPECIFICATIONS Dimensions: 16.8”W x 12.6”H x 12”D (42.7 cm x 32.0 cm x 30.5 cm);

Weight: 35 lbs (15.9 kg)

AMPERE METER INPUT

RANGES

VOLT METER INPUT RANGE 0 – 600.0V; AC accuracy: 1% of reading ±1 count; DC accuracy 0.5% of

AUXILIARY POWER SUPPLIES 24 Vdc @ 1 A, 124 Vdc @ 0.25 A, 240 Vac @ 0.125 A

SAFETY Designed to meet IEC61010 (1995), UL61010A-1, CSA-C22.2 standards

ENVIRONMENT Operating: -10˚C to 50˚ C (15˚F to +122˚ F); Storage: -30˚ C to 70˚ C (-

OPTIONS Transportation case

WARRANTY One year on parts and labor

Internal input range: 0 – 250 A; Accuracy: 2% of reading ± 10 mA,
External AC input range: 0 – 6A; Accuracy: 1% of reading ± 10mA
External DC input range: 0 – 6A; Accuracy: 0.5% of reading ±1 count
Measurement Method: True RMS for AC

reading ±1 count
Measurement Method: True RMS for AC

22˚F to +158˚ F)

The above specifications are valid at nominal operating voltage and at a
temperature of 25°C (77°F). Specifications may change without prior notice.

NOTE

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Table 2. RFD-200 S2 Output Specifications

AC CURRENT OUTPUT

Range No-Load Voltage Load Voltage Load Current Load/Unload Times

10A 90 Vac 75 Vac 10 A 2 min / 15 min

40 A 25 Vac 20 Vac 40 A 1 min / 15 min
100 A 10 Vac 7.25 Vac 100 A 1 min / 15 min
100 A 10 Vac 3 Vac 250 A 1 sec / 5 min

AC VOLTAGE OUTPUT

Range No-Load Voltage Load Voltage Load Current Load/Unload Times

250 Vac 260 Vac 240 Vac 3 A 10 min / 45 min

DC VOLTAGE OUTPUT

Range No-Load Voltage Load Voltage Load Current Load/Unload Times

300 Vdc 300 Vdc 250 Vdc 2A 10 min / 45 min

Table 3. RFD-200 S2 Timing Accuracy

RFD-200 S2 TIMER SECOND DISPLAY

IN SECONDS AND CYCLES (50/60 HZ PROGRAMMABLE)

Range Resolution Accuracy

0 to 9.999 sec 1 ms ± (1 ms + 0.01%)

10.00 to 99.99 sec 10 ms ± (10 ms + 0.01%)

100.00 to 999.999 sec 100 ms ± (100 ms + 0.01%)

TIMER CYCLES DISPLAY

Range Resolution Accuracy

0 to 9.999 cycles 0.1 cycle ± (0.1 cycle + 0.01%)
1,000 to 49,999 cycles / 50 Hz 1 cycle ± (1 cycle + 0.01%)

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1.4 Controls and Indicators

The RFD-200 S2’s controls and indicators are shown in Figure 1. A leader line with an index
number points to each control and indicator, which is cross-referenced to a functional
description in Table 4. The table describes the function of each item on the control panel. The
purpose of the controls and indicators may seem obvious, but users should become familiar
with them before using the RFD-200 S2. Accidental misuse of the controls will usually cause no
serious harm. Users should also be familiar with the safety summary found on the front page of
this User’s Manual.

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Figure 1. RFD-200 S2 Controls and Indicators

RFD-200 S2 USER’S MANUAL REV 2

Table 4. Functional Descriptions of RFD-200 S2 Controls and Indicators

Item

Number

1
2
3
4

5

6

7

8
9

10
11
12
13
14
15

16
17

18

19

20
21

22
23
24
25
26
27
28
29
30

Panel Markings Functional Description

COM Curren t source common terminal
100A 100A curre n t so u r ce te rmi n al

40A 40A current source termina l
10A 10A current source terminal

0-250 Vac

3A

0-300 Vdc

3A

EXT INPUT

CURRENT

6A MAX

Power resistor array

110-120 Vac

12A, 50-60 Hz

GROUND Ground terminal

VOLTAGE INPUT

600V MAX

RS-232 RS-232C (serial) port for factory firmware programming and diagnostics

OUTPUT

CONTROL

RFD-200 S2 timer, current source and voltage source control buttons

6A External current input circuit breaker

CONTRAST LCD screen contrast control button

240 VAC

.125A

124 VDC

.25A

24 VDC

1A

PWS SELECT Auxiliar y power supply selection button

240-260 VAC 240 Vac power supply output terminals
124-136 VDC 124 Vdc power supply output terminals

24-28 VDC 24 Vdc power supply output terminals

ON/OFF Power supply ON/OFF button

Timer STOP method selection button

TIMER STOP Timer STOP input terminals

Timer START method selection button

TIMER START Timer START input terminals

METER SELECT Internal/external current display selection button

AC voltage source terminals

DC voltage source terminals

External current input terminals

Back-lit LCD screen (20 characters by 4 lines), viewable in bright sunlight and
low-light levels

Power switch with built-in circuit breaker

External voltage input terminals

Voltage and current source control knob

240 Vac power supply fuse (1/8 A)

124 Vdc power supply fuse (1/4 A)

24 Vdc power supply fuse (1A)

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REV 2 RFD-200 S2 USER’S MANUAL

2.0 FUNCTIONAL DESCRIPTION

2.1 RFD-200 S2 Auxiliary Power Supply

The RFD-200 S2 provides 3 auxiliary power supplies (24 Vdc, 124 Vdc, 240 Vac) for powering
electronic relays. Each power supply is fuse-protected. The power supply outputs are controlled
by the auxiliary power supply [ON/OFF] button (item 25 in Figure 1). The LED next to the

[ON/OFF] button is illuminated when the power supply output is turned on.

Only one auxiliary power supply can be selected at a time. The [PWS SELECT] button (item
21 in Figure 1) is used to select the power supply. The active power supply is indicated by an
illuminated LED above the corresponding voltage label.

2.2 RFD-200 S2 Current and Voltage Sources

The RFD-200 S2 front panel offers three AC current source terminals (100A, 40A, 10A). Only one
current source should be used at a time. The
whether to display the current generated by the RFD-200 S2 or the current input at the

INPUT CURRENT]

terminals. The [RFD-200 CURRENT] LED will be illuminated when an

[METER SELECT] button is used to select

[EXT

internal RFD-200 current source is in use and the output current is displayed on the LCD. The
internal current is labeled as “Int I:” on the LCD screen as shown below:

0mS 0.0CY
V Mtr: -0.003 V
Int I: 0.080 A
Ext I: -0.001A

Internal Current

Two isolated voltage sources are also available, one 0-250 Vac and one 0-300 Vdc. Both the
current and voltage sources are controlled by the

[OUTPUT CONTROL] knob (item 14 in

Figure 1).

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RFD-200 S2 USER’S MANUAL REV 2

2.3 Control Switches

2.3.1. Voltage and Current Source Output Controls

The RFD-200 S2’s voltage and current source outputs are controlled by the [UP ARROW] and

[DOWN ARROW] buttons (item 15 in Figure 1). There are four control settings for the

voltage/current sources:

• START-ON

When this mode is selected, the RFD-200 S2 turns on the voltage/current sources and
starts the timer.

• OFF

When this mode is selected, the voltage/current sources are turned off and the timer is
stopped.

• ON

In this mode, both the voltage and current sources are turned on and remain on until
turned off by the user.

• START-OFF

In this mode, the RFD-200 S2 turns off the voltage/current sources and starts the timer.

The selected mode is indicated by an illuminated LED next to the label.

The voltage and current source settings are controlled by the [OUTPUT CONTROL] knob.

2.3.2. LCD Contrast Control

To change the LCD screen’s contrast, press and hold the [CONTRAST] button (item 17 in
Figure 1). The screen contrast will increase until it reaches the darkest setting. Then it will
return to the lightest setting and begin increasing the contrast again. Release the

[CONTRAST] button when the desired contrast level has been reached. The contrast setting

will be stored in the RFD 200 S2’s memory.

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REV 2 RFD-200 S2 USER’S MANUAL

2.4 Timer Start and Timer Stop Inputs

The RFD-200 S2’s built-in timer displays the test results in both
milliseconds and cycles.

There are three selections for the [TIMER START] input:

• INTERNAL

Timer starts when voltage/current sources are turned
on or off (user selects Start-On mode or Start-Off
mode).

• DRY

A change in state of a dry contact input after the user
has selected the Start-On mode or Start-Off mode will
start the timer.

• WET

A change in state of a wet contact input after the user has selected the Start-On mode
or Start-Off mode will start the timer.

There are three selections for the [TIMER STOP] input:

• INTERNAL

Timer stops when the user selects OFF mode.

• DRY

A change in state of a dry contact input after the timer has started will stop the timer.

• WET

A change in state of a wet contact input after the timer has started will stop the timer.

1. A voltage level from 20 to 255 Vac/dc is considered as “ON”. Voltage less than 10

NOTES

Vac/dc is considered as “OFF”. The input is not polarity sensitive.

2. The dry contact input detects contact closed (shorted) or contact opened.

3. Applying a voltage to the timer “Dry” contact input may damage the RFD-200 S2

2.5 RFD-200 S2 Power Resistors

Five power resistor connections are available on the RFD-200
S2. A finer control of the current output can be achieved by
connecting one or more resistors in series with the current
source.

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2.6 RFD-200 S2 External Voltage Input

One external voltage input is available on the RFD-200 S2. Maximum
input voltage is 600V. The external voltage is labeled as “V Mtr:” on the

LCD screen as shown below:

0mS 0.0CY
V Mtr: -0.003 V
Int I: 0.080 A
TMR: Single Input

2.7 RFD-200 S2 External Current Input

The RFD-200 S2 features one external current input. The
maximum input current is 6A. The external current is labeled
as “EXT I:” on the LCD screen as shown below:

0mS 0.0CY
V Mtr: -0.003 V
Int I: 0.080 A
Ext I: -0.001A

RFD-200 S2 USER’S MANUAL REV 2

External Voltage

External Current

NOTE

The [EXT INPUT CURRENT] LED must be illuminated in order to display the
external current on the LCD screen.

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3.0 OPERATING PROCEDURES

3.1 Setting the Voltage or Current Source

Use the steps below to set the voltage or current source:

a. Ensure that the RFD-200 S2 output is off. When the unit is first turned on, the output

will be off by default.

b. Connect the device under test (DUT) to an RFD-200 S2 voltage or current output. If the

RFD-200 S2 voltage source is used, the voltage can be monitored using the RFD-200 S2’s

[EXTERNAL VOLTAGE INPUT]. To monitor the voltage, connect the RFD-200 S2

voltage source output to the RFD-200 S2’s [VOLTAGE INPUT] terminals.

c. Turn the [OUTPUT CONTROL] knob counter-clockwise to the zero position (until the

knob will no longer turn.

d. Select ON by pressing the [DOWN ARROW] key in the control mode area. The [ON]

LED will be illuminated and the unit will start beeping.

e. Turn the

[OUTPUT CONTROL] knob clockwise up to the desired voltage or current.

The voltage or current settings will be displayed on the LCD screen as shown below.

0mS 0.0CY
V Mtr: -0.004 V
Int I: 1.390 A
TMR: Dual Input

1. Press the [UP ARROW] key in the control mode area to select OFF and turn

off the voltage/current source.

NOTES

2. The RFD-200 S2 current source output is displayed on the LCD screen when

the [RFD-200 CURRENT] LED is illuminated.

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RFD-200 S2 USER’S MANUAL REV 2

3.2 Setting the RFD-200 S2 for a Time Delay Test

Use the steps below to measure an over-current relay time delay:

a. Connect the RFD-200 S2 current source output across the relay coil as shown in Figure 2.
b. Select INTERNAL for the [TIMER START] input by pressing the [LEFT ARROW] key

in the TIMER START section until the [INTERNAL] LED light is illuminated. When the
RFD-200 S2 is first turned on, this mode will be selected by default.

c. Connect the

[TIMER STOP] input across the relay dry contact output as shown in

Figure 2.

d. Select DRY for the [TIMER STOP] input by pressing the [LEFT ARROW] key in the

TIMER STOP section until the [DRY] LED light is illuminated. When the unit is first
turned on, this mode will be selected by default.

e. Set the test current (see section 3.1).
f. Turn off the current source by selecting OFF from the control mode area.

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REV 2 RFD-200 S2 USER’S MANUAL

or STO

g. Select START-ON from the control mode area.

The RFD-200 S2’s timer will start when it energizes the coil voltage, and it will stop when
the relay dry contact changes state. The elapsed time will be displayed during the test in
seconds and cycles on the LCD screen:

15.7000S 1057CY
V Mtr: -0.003 V
Int I: 2.080 A
TMR: Dual Input

h. The [TEST COMPLETE] LED and the data on the LCD screen will flash when the test

has finished (a change of state in the [TIMER STOP] input is detected):

The time delay will be displayed on the LCD screen in milliseconds and cycles. The
injected test current is also displayed on the LCD screen. A typical test results screen is
shown below (actual screen will be flashing):

19.7000S 1182CY

Time delay in seconds and cycles

V Mtr: -0.003 V
Int I: 2.080 A
TMR: Dual Input

Test current injected

Dual inputs used:
INTERNAL for START TIMER
DRY f

P TIMER

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RFD-200 S2 USER’S MANUAL REV 2

Figure 2. Typical Over Current Relay Connection

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REV 2 RFD-200 S2 USER’S MANUAL

3.3 Using the RFD-200 S2’s Timer to Test Circuit Breaker Response Time

Use the steps below to use the RFD-200 S2’s timer to measure the opening time of a circuit
breaker. The timer will start when the RFD-200 S2 detects the voltage being applied to the
circuit breaker trip coil. The timer will stop when the RFD-200 S2 detects that the circuit
breaker contact has opened.

a. Connect the

[TIMER START] input to the circuit breaker coil terminals as shown in

Figure 3.

b. Select WET for the

[TIMER START] input. The timer will start when the trip coil is

energized.

c. Connect the [TIMER STOP] input to the circuit breaker dry contact as shown in Figure

3.

d. Select DRY for the [TIMER STOP] input. The timer will stop when the circuit breaker

contact is opened.

e. Turn the [VOLTAGE CONTROL] knob counter-clockwise to zero (until it can no

longer be turned).

f. Select START-ON from the control mode area.

g. Open the circuit breaker. The RFD-200 S2’s timer will start when the circuit breaker coil

voltage is detected, and it will stop when the circuit breaker contact has opened.

h. The

[TEST COMPLETE] LED will be illuminated when the test has finished. The time

will be displayed on the LCD screen in milliseconds and cycles.

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RFD-200 S2 USER’S MANUAL REV 2

Figure 3. Typical Circuit Breaker Timing Connection

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REV 2 RFD-200 S2 USER’S MANUAL

3.4 Using the RFD-200 S2’s Timer in Single Input Mode

The RFD-200 S2’s timer can also be started and stopped with only the [TIMER START] input.
This feature is handy for measuring the time duration of the [TIMER START] input when it
changes states and then returns to the previous state as shown below:

This features works only with the DRY or WET mode of the [TIMER START] input.

To select the single input mode, press and hold the [TIMER STOP ARROW] key for 2
seconds. The following screen will be displayed momentarily:

Trigger Mode Set

To Single Input

Use the steps below to measure the time a relay contact remains open:

a. Press and hold the [TIMER STOP ARROW] key for 2 seconds to select Single Input

Mode.

b. Connect the [TIMER START] inputs to the relay’s (Normally Closed) contact.
c. Select DRY mode for the [TIMER START] input.

d. Select START-ON from the control mode area.

e. Energize the relay coil to open the relay’s Normally Closed contact. The RFD-200 S2’s

timer will start and the time will be displayed on the LCD screen.

f. De-energize the relay coil to close the relay contact. The RFD-200 S2’s timer will stop

and the time will be displayed on the LCD screen.

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RFD-200 S2 USER’S MANUAL REV 2

g. Press and hold the [TIMER STOP ARROW] key for 2 seconds to return the RFD-200

S2’s timer to dual input mode. The following screen will be displayed momentarily:

Trigger Mode Set

To Dual Input

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3.5 Using the RFD-200 S2 to Plot a Current Transformer Excitation Curve

Use the steps below to find the excitation curves of a current transformer (CT):

a. Connect the RFD-200 S2 AC voltage source to the CT secondary winding in series with

the external current input as shown in Figure 4.

b. Connect the RFD-200 S2 AC voltage source to the RFD-200 S2 external voltage meter as

shown in Figure 4.

c. Select ON from the control mode area.

d. Slowly raise the AC test voltage. Observe and record the excitation voltage and current

displayed on the LCD screen.

e. Continue to raise the test voltage and record the excitation voltage and current

readings.

f. When the excitation current reaches saturation (from 1.5A to 2.0A), lower the voltage

to zero.

g. You can now plot the CT excitation curves using the collected voltage and current

readings.

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RFD-200 S2 USER’S MANUAL REV 2

Figure 4. Typical CT Excitation Test Connection

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3.6 Using the RFD-200 S2 to Measure CT Primary and Secondary Currents

Use the steps below to measure the CT primary and secondary currents with the RFD-200 S2:

a. Connect the RFD-200 S2 current source through the CT primary current path as shown

in Figure 5.

b. Connect the CT secondary winding to the RFD-200 S2 [EXT INPUT CURRENT] input

as shown in Figure 5.

c. Turn on internal and external current display on the RFD-200 S2 by pressing the

[METER SELECT] key. You may have to press the key a few times till both the [RFD­200 CURRENT]

and the [EXT INPUT CURRENT] LED’s are illuminated.

d. Select ON from the control mode area.

e. Raise the test current to the desired setting.
f. The primary and secondary current readings will be displayed on the LCD screen as

shown below:

0mS 0.0CY
V Mtr: -0.003 V
Int I: 100.00 A
Ext I: 5.000 A

The CT turns ratio can be calculated using the primary and secondary current
readings.

NOTE

g. Return the test current to zero.

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h. Select OFF from the control mode area.

RFD-200 S2 USER’S MANUAL REV 2

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24

Figure 5. Typical CT Turns Ratio Test Connection

1520 S. Hellman Ave • Ontario, CA 91761 • USA

Phone: [phone] • Fax: [phone]

www.vanguard-instruments.com

Copyright © 2009 by Vanguard Instruments Company, Inc.

RFD-200 S2 User’s Manual • Revision 2 • September 25, 2009 • TA