T&R PCU1 Series Operating instructions

1
OPERATING AND MAINTENANCE MANUAL
Product: Primary Current Injection System
Type: PCU1-SP mk2
PCU1-LT mk2
DESIGNED AND MANUFACTURED BY:
T & R Test Equipment Limited
15-16 Woodbridge Meadows, Guildford, Surrey, GU1 1BJ, United Kingdom
Telephone: [phone] e-mail: [e-mail]
Fax.: [phone] Web: www.trtest.com

2
GENERAL SAFETY STATEMENT
WARNING
The following safety precautions should be reviewed to avoid injury to the user and damage to the
product (and other products connected to it). To avoid potential hazards only use this product as
specified.
 Only suitably qualified personnel should use this equipment. Servicing of this product
should only be carried out by suitably qualified service personnel.
To Avoid Fire Hazards and Personal Injury
 Use the correct power supply lead. Only use a suitably rated and approved power supply lead for
the country of use.
 Ensure that systems that the unit is to be connected to are isolated from the supply and earthed.
 Do not connect and disconnect leads whilst outputs are switched on. Breaking the output circuit
with current flowing may cause potentially fatal arcing.
 Ensure that the product is grounded. To avoid electric shock it is essential that the grounding
conductor is connected to the earth ground. An additional earth terminal is provided on the unit that
should be connected to a local earth. Ensure that the unit is properly grounded before making any
connections to inputs or outputs.
 Terminal ratings must be observed to prevent fire hazards and risk of injury to the operator.
Consult the product manual for ratings information before making connections to any terminal.
 It is ESSENTIAL to consult the product manual for rating information before making any connection
to a terminal or terminal group marked with a warning triangle.
 Only use fuses of a type and rating specified for this product.
 Do not operate the unit out of its case or with any covers or panels removed.
 Do not touch exposed connections and components when power is present.
 Do not operate the product if any damage is suspected. Refer the unit to qualified service
personnel to be checked.
 Do not operate the unit in wet or damp conditions
 Do not operate the unit in an explosive atmosphere
 The PCU1 systems have a very high output current (up to 10kA), and therefore generate large
magnetic fields around the output leads and loading transformer. Care must be taken in siting the
unit next to items sensitive to magnetic fields (such as computer monitors and other sensitive
equipment).
 Warnings from cardiac pacemaker manufacturers state that strong magnetic fields may affect
operation. Any high current unit such as the PCU1 should therefore not be operated by, or in the
vicinity of persons fitted with cardiac pacemakers or any other electronic or electrical medical
implants.
If any further queries occur regarding the usage and maintenance of the equipment
detailed in this manual, please refer these to the supplier of the equipment in the first case
or to the manufacturer, T & R Test Equipment Limited.

3
SAFETY TERMS AND SYMBOLS
The following safety symbols appear on the equipment:
CAUTION/WARNING – Refer to manual
HOT – Refer to manual
Mains off
Mains on
The following safety symbols appear in this manual:
CAUTION
This action or procedure may be dangerous if not carried
out correctly and may cause damage to the equipment or
connected equipment.
WARNING
This action or procedure may cause injury or death to the
operator or other personnel if not carried out correctly using
applicable safety procedures.
HOT Parts of the unit may become hot during use, particularly
when operating at high currents

5
CONTENTS
1. DESCRIPTION OF EQUIPMENT 9
1.1 Control Unit Front Panel Layout and Functions 10
1.2 Loading Unit Front Panel Layout 12
1.2.1 NLU2000 & NLU5000 12
1.2.2 NLU200 13
1.3 Electrical Specification 14
1.3.1 Supply Requirements 14
1.3.2 Loading Unit Outputs 15
1.3.3 Secondary Injection Output (PCU1-SP only) 16
1.3.4 Metering 16
1.3.5 Timing System 18
1.4 Displayed Values and Messages 19
1.4.1 Displayed Values 19
1.4.2 Warning Messages 19
1.5 Primary Current Injection Lead Sets 21
1.5.1 Description 21
1.5.2 Factors Affecting Maximum Output Current 22
1.5.3 Lead Set Voltage Drops 23
1.5.4 Unit Output Voltage Under Load 23
1.6 Overload Protection 24
1.7 Construction 24
1.8 Installation 25
2. OPERATION 26
2.1 Primary Current Injection with Loading Unit 26
2.1.1 Connections 26
2.1.2 Testing 27
2.1.3 After Testing 27
2.2 Secondary Current Injection (PCU1-SP only) 28

6
2.2.1 Connections 28
2.2.2 Testing 28
2.2.3 After Testing 29
2.3 Timing System 29
2.3.1 Timer Modes 30
2.3.2 General Procedure for Timing Tests 31
3 APPLICATION NOTES – TESTING SPECIFIC DEVICES 33
3.1 Secondary Injection of an Over-Current Relay (PCU1-SP only) 33
3.1.1 Timer Mode 33
3.1.2 Connections 33
3.1.3 Test Procedure 33
3.2 Primary Injection of an Over-Current Relay (PCU1-SP & LT) 34
3.2.1 Timer Mode 34
3.2.2 Connections 34
3.2.3 Test Procedure 34
3.2.4 Using Pulse Mode to Set the Current 34
3.3 Timing of Auto-reset/Reclosing Devices (PCU1-SP & LT) 35
3.3.1 Timer Mode 35
3.3.2 Connections 35
3.3.3 Test Procedure 35
3.4 Timing Devices with NO Auxiliary Contacts (PCU1-SP & LT) 36
3.4.1 Timer Mode 36
3.4.2 Connections 36
3.4.3 Test Procedure 36
3.5 Using the Control Unit as a Single Contact Timer (PCU1-SP & LT) 37
3.5.1 Timer Mode 37
3.5.2 Connections 37
3.5.3 Test Procedure 37
3.6 Using the Control Unit as a Dual Contact Timer (PCU1-SP & LT) 37
3.6.1 Timer Mode 37
3.6.2 Connections 37

7
3.6.3 Test Procedure 37
3.7 CT Polarity (PCU1-SP only) 38
3.7.1 Modes & Settings 38
3.7.2 Connections 38
3.7.3 Test Procedure 38
3.8 CT Ratio (PCU1-SP only) 39
3.8.1 Modes & Settings 39
3.8.2 Connections 39
3.8.3 Test Procedure 39
4. MAINTENANCE 41
4.1 Output Control Brushes 41
4.2 Removal of the PCU1 from Case 41
5. STANDARD ACCESSORIES 43
5.1 Spare Fuses Supplied: 43
5.2 Standard Accessories Supplied: 43
6. OVERALL PERFORMANCE SPECIFICATION 45
6.1. Insulation Resistance at 1000V DC 45
6.2. Applied Voltage Test 45
6.3. Accuracy of Instruments 45
6.3.1 Loading Unit Current Output 45
6.3.2 Secondary Injection Current Output (PCU1-SP only) 46
6.3.3 Auxiliary Metering Input 46
6.3.4 Timing System 46
7. REVISION 47

9
1. DESCRIPTION OF EQUIPMENT
The PCU1 mk2 series are medium powered primary current injection systems offering output
currents up to 5000A. The system consists of a separate control unit containing all metering
and control functions and a loading unit that provides the high current output. The PCU1-LT
mk2 and PCU1-SP mk2 are ideally suited to primary current injection, stability testing and
circuit breaker testing. In addition, the SP version offers direct-reading CT ratio and polarity
tests and a 100A secondary injection output.
All references to the PCU1-SP and PCU1-LT in this manual refer to the PCU1-SP mk2 and
PCU1-LT mk2.
Three loading units are available, delivering a maximum output current of 200A, 2000A or
5000A. Each loading unit has two or three output taps to allow for a wide range of load
impedances. For example, the NLU5000 may be configured to either give a maximum current
of 5000A on the 2.3V range, 2500A on the 4.6V range or 1250A on the 9.2V range.
The control units are rated at 11.5kVA. All metering is digital, and a memory facility is
provided to hold the current reading when the output trips or is switched off. The current is
thyristor controlled and is automatically switched off when the device under test trips.
The PCU1 systems have a high accuracy timing system, allowing timing tests to be carried
out to a resolution of 1ms. Selection for normally open or normally closed contacts is
automatic, and the status of the contacts is shown on the front panel.
Timing modes are available to test under and over current devices, re-closers, under and over
voltage devices, current trips and circuit breakers. A full range of high current output leads
are available to complement the system in a range of lengths.
WARNING
The PCU1 and associated loading units are designed to be used on ‘dead’
systems (i.e. no externally supplied vol
tages are present on the test object).
Under no circumstances connect a PCU1 to a live system. Always check that
the power to the device under test is off and the circuit is isolated and earthed
before making any connections.

10
1.1 Control Unit Front Panel Layout and Functions
Figure 1.1 PCU1-SP mk2 front panel layout
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T

11
UNIT
TYPE
ITEM FUNCTION
LT SP
A  Secondary Injection Output 0-100A Secondary injection output
B   NLU metering connection Metering/control connection to loading unit
C   Output circuit breaker Protection for primary current output
D   Loading unit power connector Power supply to loading unit
E   Metering range/output selection
switch
Selects between outputs on PCU1-SP
(primary/secondary injection) and metering
range (LT/SP)
F   Mains input switch/circuit breaker Supply isolation switch and protection
G   Mains inlet connector Mains supply connection
H   Earth terminal Connect to local earth.
I   Fuse Fuse for metering and control circuits
J   RS232 connector Serial connection for PC/printer connection
K   T&R link connector Output to phase lock DVS3 mk2 to PCU1
L   Main output control Sets output current
M   Output on and off pushbuttons Switch output on and off and indicate output
state
N   Timer display Display of timer value
O   Metering range display Full scale of current metering range for
primary injection
P  Auxiliary metering display Display of selected auxiliary meter value
Q   Current display Output current
R  Auxiliary metering inputs Voltage and current input for auxiliary
metering circuit
S   Timer inputs and selector Timer mode selection switch and contact
inputs
T  Output trip Secondary current injection circuit breaker

12
1.2 Loading Unit Front Panel Layout
The PCU1 system is available with a range of optional loading units and output lead sets.
The loading unit is connected to the control unit using a metering cable and a power cable.
Three output taps are provided for connection to the load. The load is connected between the
common terminal and one of the output taps.
1.2.1 NLU2000 & NLU5000
Figure 1.3 Loading unit front panel
ITEM FUNCTION
A PCU1 metering connection Metering/control connection to control unit
B Power connector Power supply from control unit
C Tap 3 output Highest voltage, lowest current output
(1250A 9.2V on NLU5000)
D Tap 2 output Highest voltage, lowest current output
(2500A 4.6V on NLU5000)
E Tap 1 output Highest voltage, lowest current output
(5000A 2.3V on NLU5000)
F Common output Output common terminal. One of the output
leads is always connected to this terminal.
For CT polarity testing this is the P2 terminal.
G Trolley mounting point Four mounting points are provided on each
unit to allow them to be mounted on the
optional trolley
A
B
C
D
E
F
G

13
1.2.2 NLU200
ITEM FUNCTION
A PCU1 metering connection Metering/control connection to control unit
B Power connector Power supply from control unit
C Common output Output common terminal. One of the output
leads is always connected to this terminal.
D Tap 1 output Highest current, lowest voltage output
200A 60V
E Tap 2 output Highest voltage, lowest current output
100A 120V
F Trolley mounting point Four mounting points are provided on each
unit to allow them to be mounted on the
optional trolley
D
A
B
E
F
C

14
1.3 Electrical Specification
1.3.1 Supply Requirements
The PCU1 systems require a single phase 50/60Hz supply of 230V±10%. The maximum
power requirement of the system depends on the level of current to be drawn from the control
unit. For maximum output a 50A supply is required, but in most situations a 32A supply will
suffice.
Loading unit Open Circuit
Voltage Load current Max time for load current
Supply
current
NLU5000
2.3V
3000A 5 minutes 30A
5000A 40 seconds 50A
4.6V
1500A 5 minutes 30A
2500A 40 seconds 50A
9.2V
750A 5 minutes 30A
1250A 40 seconds 50A
NLU2000
3.5V
1200A 5 minutes 18A
2000A 40 seconds 30A
6.9V
600A 5 minutes 18A
1000A 40 seconds 30A
13.8V
300A 5 minutes 18A
500A 40 seconds 30A
NLU200
60V
80A 5 minutes 21A
200A 40 seconds 50A
120V
40A 5 minutes 21A
100A 40 seconds 50A
Overload ratings are also available when operating in pulse mode. In this mode the output
current (and therefore supply current) may be higher for a maximum of two seconds. In every
case the maximum achievable output current is defined by the output cable and load
impedance.

15
1.3.2 Loading Unit Outputs
Each loading unit has two or three output taps. The highest currents are available on the
lowest voltage taps.
Loading
unit
Open
Circuit
Voltage
Continuous
current
Intermittent current
5 min on/
15 min off
1 min on/
15 min off
40s on/
15 min off
NLU5000
2.3V 1500A 3000A 4500A 5000A
4.6V 750A 1500A 2250A 2500A
9.2V 375A 750A 1125A 1250A
NLU2000
3.5V 600A 1200A 1800A 2000A
6.9V 300A 600A 900A 1000A
13.8V 150A 300A 450A 500A
NLU200
60V 40A 80A 160A 200A
120V 20A 40A 80A 100A
Each output is rated for a continuous current and also for higher intermittent currents. The
maximum ‘on’ time for intermittent currents is enforced by the unit, and the output will be
switched off if the rating is exceeded. The display will then show the following message until
the green ‘off’ button is pressed to clear the trip condition:
Output Tripped
Press Green to Reset
NOTE: If the metering cable is not connected between the control unit and the external loading unit,
the ammeter will not function and the output will not switch on when the output ON push-
button is pressed. The metering cable between the control and external loading unit acts as
an interlock circuit.
The control unit automatically selects the correct metering ranges and protection for the
loading unit connected.

16
1.3.3 Secondary Injection Output (PCU1-SP only)
The PCU1-SP has a two-tap secondary injection output capable of injecting up to 100A
without the use of a loading unit. The secondary injection output is selected using the
metering range select switch.
Unit Range Voltage
Current
Continuous 5 min on/
15 min off
1 min on/15
min off
PCU-SP
33A 15V 10A 20A 33A
100A 5V 33A 67A 100A
The secondary injection output will only activate if the power lead to the loading unit is
disconnected.
1.3.4 Metering
The PCU1 systems are fitted with a memory ammeter that holds the output current at the
moment that the output circuit is switched off. In timing modes where the contact inputs are
used to signify the end of a test, the last valid current before the contacts changed state is
held. This also holds true for the current operated timer mode. The ammeter will capture and
calculate the rms of a single cycle of output current.
The output metering ranges for the loading unit depend on the loading unit connected. The
metering ranges are identified as 10%, 50% and 100% on the control unit. These relate to the
maximum current that is available from the loading unit (on an NLU5000 the metering ranges
are 500A, 2500A and 5000A).
1.3.4.1 Loading Unit Ammeter Ranges
Loading unit Metering range
Metering full
scale Accuracy Trip current
NLU5000
10% 500.0A 0.5%rdg+5d 525A
50% 2500A 0.5%rdg+5d 2625A
100% 5000A 0.5%rdg+5d 5250A
NLU2000
10% 200.0A 0.5%rdg+5d 210A
50% 1000A 0.5%rdg+5d 1050A
100% 2000A 0.5%rdg+5d 2100A
NLU200
10% 20.00A 0.5%rdg+5d 21A
50% 100.0A 0.5%rdg+5d 105A
100% 200.0A 0.5%rdg+5d 210A

17
1.3.4.2 Secondary Injection Output Ammeter Ranges (PCU1-SP only)
Unit Ammeter
range Accuracy Trip current
PCU1-SP
10.00A ±0.5%rdg±5d 10.5A
20.00A ±0.5%rdg±5d 21A
100.0A ±0.5%rdg±5d 105A
1.3.4.3 Auxiliary Meter Ranges (PCU1-SP only)
The PCU1-SP has an auxiliary metering input with 300V/5A inputs. This can additionally
measure the phase angle between output current and auxiliary input or the ratio between
output current and auxiliary current.
Auxiliary metering
range Full scale Function
RMS 300.0V/5.000A
Accuracy
±0.7%rdg±5d
Displays the RMS voltage or current of the
signal connected to the input
CT polarity Fwd/Rev Indicates the polarity of a CT connected
between the current output (primary) and
auxiliary current input (secondary)
CT ratio 5A 5000:5A Displays the ratio of a 5A CT connected
between the current output (primary) and
auxiliary current input (secondary)
CT ratio 1A 5000:1A Displays the ratio of a 1A CT connected
between the current output (primary) and
auxiliary current input (secondary)
Phase -179.9° to +180.0° Displays the phase angle between the
output current and the voltage or current
connected to the auxiliary input. Only active
if the output current is <10% of the selected
metering range and the auxiliary input is
>0.5A or 20V.
Hz 45.00-99.99Hz Displays the frequency of the voltage or
current of the signal connected to the input.
Only active if the auxiliary input is >0.5A or
20V.

18
1.3.5 Timing System
The PCU1 systems are fitted with an integrated timing system linked to the output and the two
sets of contact inputs. The system is highly flexible, and allows for the timing of all common
protection devices and trips. The timer may also be used to time external events not linked to
the output of the set. The timer is auto-ranging.
Full details of operating the timer are given in section 2.
Timer mode Range Resolution Accuracy
Pulse 2s 0-2.000s 1ms 0.01% rdg 2d
Pulse 1s 0-1.000s 1ms 0.01% rdg 2d
Pulse 0.5s 0-0.500s 1ms 0.01% rdg 2d
Pulse 0.2s 0-0.200s 1ms 0.01% rdg 2d
Off - - -
Internal start
0-999.999s/
0-9999.99s/
0-99999.9s
1ms/
10ms/
100ms
0.01% rdg 2d
Single contact 0.01% rdg 2d
Dual contact 0.01% rdg 2d
Current operated 0.01% rdg 4d
In current operated mode timing results obtained with test currents below 20% of the selected
ammeter range are of doubtful accuracy and should be ignored.
The PCU1 systems have two contact inputs which are used to start and stop the timer
depending on the mode selected. Each input has a connection for volt-free contacts and for
triggering by a DC voltage. In each case, the input auto-selects for normally open or normally
closed contacts. The contact state is shown by an LED (off when the contact is closed, on
when the contact is open).
The maximum open circuit voltage across the contact input is 24V, and the short circuit
current through the contacts is limited to 20mA.
The contact inputs are fully isolated.

19
1.4 Displayed Values and Messages
1.4.1 Displayed Values
The PCU1 display simultaneously shows the injected test current, the loading unit metering
range full scale, the timer result, the selected auxiliary input value and quantity (SP models
only), and the state of the output on a liquid crystal display. It also displays warning and error
messages, detailed in the following section.
PCU1-SP Output current FS of loading unit range Timer
3000.A 5kA 0.000s
3000.:5A 5.000A
Auxiliary metering
PCU1-LT Output current FS of loading unit range Timer
3000.A 5kA 0.000s
Figure 1.4 Normal values displayed on screen
1.4.2 Warning Messages
In addition to the normal display screens, the PCU1 systems can display a range of warning
messages if the unit trips on over-current or duty cycle or is too hot internally. If an over
current or duty cycle trip occurs, the green ‘off’ pushbutton must be pressed to clear the trip
condition. If the unit trips on over temperature, the unit will automatically reset when the
temperature falls to an acceptable level. If the unit is over temperature, switching the unit off
and back on will not clear the message – the unit must be allowed to cool.
Output Tripped
Press Green to Reset
Figure 1.5 Over-current trip warning message
Duty Cycle Trip
Press Green to Reset
Figure 1.6 Duty cycle trip warning message
Over Temperature
Output Disabled
Figure 1.7 Unit over temperature warning message

20
Remove Loading Unit
Green to continue
Figure 1.8 (PCU1-SP only) Secondary injection selected with loading unit power lead plugged
in to PCU1
Connect Loading Unit
Green to continue
Figure 1.9 Primary injection selected with loading unit not connected
Press Green to
continue
Figure 1.10 Loading unit fault cleared, waiting for user
LU Over Temperature
Output Disabled
Figure 1.11 Loading unit over temperature