T&R PT18-10 mk2 Operating instructions

OPERATING AND MAINTENANCE MANUAL
Product:
High Voltage DC Cable Test Set
Type:
PT18-10 mk2
DESIGNED AND MANUFACTURED BY:
T & R Test Equipment Limited
15-16 Woodbridge Meadows, Guildford, Surrey, GU1 1BJ, United Kingdom
Telephone: [phone] e-mail: [email protected]m
Fax.: [phone] Web: www.trtest.com
TRUSTED & RELIABLE

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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.
•The high voltage generated by this unit is extremely dangerous and may be fatal.
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 dead.
•Do not connect and disconnect leads whilst outputs are switched on.
•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 must 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
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:
T & R Test Equipment Limited

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SAFETY TERMS AND SYMBOLS
The following safety symbols appear on the equipment:
CAUTION/WARNING –Refer to manual
DANGER –High voltage
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 be cause injury or death to the
operator or other personnel if not carried out correctly using
applicable safety procedures.

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HIGH VOLTAGE SAFETY
WARNING
It is essential to follow safe working procedures when working with high voltage. Information on accepted codes
of practice should be obtained from your local heath and safety regulatory body.
IEEE standard 510-1983 (IEEE Recommended Practices for Safety in High-Voltage and High-Power Testing)
provides a working framework for establishing safe procedures, but must be read in conjunction with local
regulations and accepted codes of practice.
The following excerpts are taken from IEEE 510
•All ungrounded terminals of the test equipment or apparatus under test should be considered as energised.
•Common ground connections should be solidly connected to both the test set and the test specimen. As a
minimum, the current capacity of the ground leads should exceed that necessary to carry the maximum
possible ground current. The effect of ground potential rise due to the resistance and reactance of the earth
connection should be considered.
•Precautions should be taken to prevent accidental contact of live terminals by personnel, either by shielding
the live terminals or by providing barriers around the area.
•The circuit should include instrumentation for indicating the test voltages.
•Appropriate switching and, where appropriate, an observer should be provided for the immediate de-
energisation of test circuits for safety purposes. In the case of dc tests, provisions for discharging and
grounding charged terminals and supporting insulation should also be included.
•High-voltage and high-power tests should be performed and supervised by qualified personnel.
•Consideration should be given to safety regulations which may apply to specific circumstances; for example,
HSE, company, or government regulations.
•In the use of signal-gathering equipment, each device should be used in such a manner that it will not
present a personnel hazard should it inadvertently become a part of the high-voltage circuit, or fail to function
properly.

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CONTENTS
1. DESCRIPTION OF EQUIPMENT 9
1.1 Electrical Specification 9
1.2 Front Panel Layout 10
1.3 Output Voltage Control 10
1.4 Overload Protection 10
1.5 High Voltage Output Cables and Connectors 11
1.6 Metering 11
1.6.1 kV Meters 11
1.6.2 mA Meters 11
1.7 Discharge and Earthing 12
1.7.1 Automatic Discharge/Earthing 13
1.7.2 Manual Earthing Using DP20 Discharge/Earthing Probe 13
1.8 Construction 13
1.9 Storage 14
2. OPERATION 15
2.1 Safety 15
2.1.1 Installation 15
2.1.2 Operation 16
2.1.3 Inspection 17
2.2 Connection and Testing 18
2.2.1 Connection Sequence 18
2.2.2 Testing Sequence: 20
2.2.3 Disconnection Sequence: 20
3. MAINTENANCE 21
4. STANDARD ACCESSORIES 23
5. PERFORMANCE SPECIFICATION 25
6. REVISION 27

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1. DESCRIPTION OF EQUIPMENT
1.1 Electrical Specification
Supply requirements 115V/230V10% auto-selecting
50/60Hz
600VA maximum
Output voltage 0-18kVdc with respect to earth
(0-36kV between outputs, centre earthed)
Output current 5mA continuous from each output
10mA from each output with a duty cycle of 5 minutes
on/15 minutes off
Output earth connection The earthy end of the high voltage outputs is connected
to the earth system of the equipment.

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1.2 Front Panel Layout
2
8
0
10
4
6
0
2
4
6
8
10
P
ABC D E
LK
MF
J
NH G
Figure 1 PT18-10 Front panel
A Positive HV output with dust cap
H Output HV on pushbutton
B Positive kV meter with dust cap
J mA range select pushbutton
C Positive mA meter
K Negative mA meter
D Supply on/off key switch
L Negative kV meter
E Mains inlet and fuse
M Negative HV output
F Output control
N Earth terminal
G Output HV off pushbutton
P HV Output blanking plug
1.3 Output Voltage Control
The voltage from the equipment is controlled by the output control on the front panel. To increase the
output voltage turn the control knob in a clockwise direction, and to decrease the output voltage turn the
knob anti-clockwise.
Note: The output can not be energised unless the regulator knob is set to zero.
1.4 Overload Protection
The unit is fitted with an F5A fast acting fuse which protects the incoming mains supply to the unit.

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The outputs from the instrument are protected by means of an electronic trip circuit. The overload is set
for 12-15mA at the output.
1.5 High Voltage Output Cables and Connectors
. Screened 5 metre long high voltage output cables are provided with the equipment terminated with
large clips. If these clips are not suitable for creating a secure connection to your test object they
should be replaced with a suitable termination. The cable type used is UR67M with a multi-stranded
inner core. The outer screen is connected via the high voltage plug to the ground connection on the
PT18-10.
Longer output cables are available as an optional accessory.
The high voltage plugs are protected in transit by plastic covers.
The high voltage plugs used on the PT18-10 are fully de-mountable.
WARNING
NEVER connect or disconnect the output leads with the unit connected to the mains.
1.6 Metering
The PT18-10 has separate, independent current and voltage metering for each output.
1.6.1 kV Meters
The equipment is fitted with two output kilovolt meters, which monitor both the positive and negative
outputs simultaneously. Both instruments have a single range of 0-18kV. Each division on the
instruments represent 1kV. The individual meters are labelled as follows:
a. Positive kV meter: +kV DC
b. Negative kV meter: -kV DC
1.6.2 mA Meters
The equipment is fitted with two output milliammeters, which sense both the positive and negative
output currents simultaneously. The individual meters are labelled as follows:
a. Positive mA meter: +mA DC
b. Negative mA meter: -mA DC
The output mA meters are dual range as follows:
Range 1: 0-10mA Each division being 0.5mA
Range 2: 0-1.0mA Each division being 0.05mA

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1.7 Discharge and Earthing
WARNING
The load must be discharged and earthed before any connections are made, broken or touched, and an
earth must be maintained on the test object at all times during testing except when high voltage is
actually applied. The unit has an internal automatic discharge system and is also supplied with a DP20
external discharge probe suitable for discharging higher capacitance loads.

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1.7.1 Automatic Discharge/Earthing
The unit has an internal fail-safe automatic discharge system with the following ratings:
•Max. discharge voltage (kVdc) 20kVdc
•Max. discharge energy 2.5kJ
•Max. discharge capacitance 10F
•Max. discharges per hour 4
The outputs are earthed by the automatic discharge/earthing system when the HV output is off or the
unit is switched off.
The automatic discharge/earthing switch is controlled by a solenoid that may produce a noticeable hum
when the HT output is energised, particularly when operating from reduced mains voltages.
CAUTION
Ensure that the energy stored in the cable under test does not exceed the capabilities of the discharge
system.
1.7.2 Manual Earthing Using DP20 Discharge/Earthing Probe
WARNING
Under no Circumstances Must the Discharge/ Earthing Probe be Used on Energised AC
Distribution Systems. Failure to Observe the Above Will Result in Severe Damage to the
Discharge Probe and, more importantly, possible fatal Injury to the operator.
The DP20 supplied with the PT18-10 has a higher rating than the internal discharge system. It has the
following ratings:
•Max. discharge voltage (kVdc) 20kVdc
•Max. discharge energy 3.6kJ
•Max. discharge capacitance 15F
•Max. discharges per hour 4
CAUTION
Ensure that the energy stored in the cable under test does not exceed the capabilities of the discharge
system.
1.8 Construction
The PT18-10 is housed in a robust case consisting of a rigid frame construction with removable side
covers to provide good access and serviceability.
All the controls are located on the equipment's front panel, together with all input and output
connections. The instrumentation is mounted on a sub-chassis which, in turn is mounted to the front
panel via a shock absorbing system. The instrumentation is further protected by means of a
polycarbonate cover to prevent damage to the instruments’ front faces.
The PT18-10 is housed in a padded bag for maximum protection during transit.

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1.9 Storage
The PT18-10 when not in use must be stored in a dry environment; corrosion damage may occur to the
HV components if stored in damp environment.
Note:
If the unit is moved from a cold area to a warmer area condensation could form on the HV
components, this would greatly reduce the internal breakdown voltage.
If it is suspected that condensation may have formed the PT18-10 should not be used until its
temperature has stabilised and any condensation evaporated.

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2. OPERATION
2.1 Safety
WARNING
The output from the PT18-10 is extremely dangerous, and if used incorrectly could be fatal. The unit
must only be installed, operated, and maintained by suitably qualified and trained personnel.
It is essential to follow accepted safety procedures and local health and safety regulations and
guidelines when installing and operating high voltage equipment. A risk assessment should be
undertaken on both the installation and the working procedures to ensure the safety of test personnel
and all other personnel.
If no local guidelines exist, IEEE Std 510-1983 (IEEE Recommended Practices for Safety in High-
Voltage and High-Power Testing) provides a framework for safe installation and testing. This standard
is available from the IEEE web site at www.ieee.org.
Test procedures and safety precautions are provided for guidance only.
2.1.1 Installation
WARNING
Incorrect installation and use of this equipment may result in injury or death.
2.1.1.2 Test Area
The unit must only be installed in a suitable high voltage test area, whether this be a permanent test
area or a temporary test area. Appropriate controls and safety measures must be applied to this area
including interlocks connected to the supply to ensure that the unit cannot be switched on unless the
area is secure. Refer to IEEE Std 510-1983 for further details of suitable test areas. The test area
must also be identified with suitable signs.
2.1.1.3 Mains supply
The unit must be connected to a suitable supply via an approved and suitably rated mains connector
with earth connection.
2.1.1.4 Earthing
Particular attention must be made in earthing the equipment, and all earth connections must be made
with substantial conductors with secure joints.
It is important for the safety of the operator and to protect the equipment that an adequate earth
connection is made.
The earth connection on the unit must be connected to a suitable low impedance earth, which may be
provided via the cable sheath (but check that the cable sheath has been properly earthed before using
it as an earth point).
The earth return from the test object must also be made with a suitable conductor back to the earth
point on the unit.
All earth connections must be able to withstand the largest fault current that may be encountered in the
system.

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2.1.2 Operation
WARNING
It is essential that safe working practices are maintained when conducting high voltage testing.
Safe working procedures must be implemented to accepted standards.
Always ensure by means of a live line tester that the cable about to be tested is not live. This
applies both to old and newly installed cables and also to all phases.
Large amounts of energy will be stored in the cable under test, and this must be discharged
safely. It is vital that the maximum energy that will have to be discharged from the cable is
calculated before commencing testing, and that appropriate arrangements are made for
discharging.
2.1.2.1 Discharge and Grounding of the Load and High Voltage Output
The output circuit and load must be discharged and grounded before any connections are made or
disconnected. The PT18-10 does include an automatic dump and grounding mechanism, but it is
important not to overload this (see section 1.7.1 and 1.7.2) A temporary ground should be maintained
at all times on the high voltage circuit when the HV is not energised. When connections are made or
disconnected, the circuit either side of the connection should be grounded first. Extra discharge
probes and earth sticks are available from T&R Test Equipment as an optional accessory.
If the test circuit includes capacitors, each capacitor should be grounded separately before connections
are made or broken. In the case of capacitors connected in series, the intermediate terminals should
also be grounded.
It is good practice for all capacitive devices to remain short-circuited when not in use.
2.1.2.3 High voltage connection
The HV connection to the test object must be made securely, and suitable stress relief components
should be used where required to keep electrical stresses within acceptable limits.
WARNING
NEVER connect or disconnect the output cables with the mains supply connected or with the HV output
switched on. Always ensure that the unused output has the plastic blanking plug (not the metal dust
cap) fitted when carrying out unipolar testing.
2.1.2.4 High voltage output clearances
WARNING
Safe clearances must maintained between the following parts and any other conducting object (whether
earthed or not):
•HV cable termination
•Non-screened part of HV cables
•Wiring connected to HV cable termination
•Non-grounded parts of test object
Any part of the test object not connected to earth should be considered live at the test voltage.

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Particular attention should be paid to clearances between any parts of the test object at test voltage
potential and the test enclosure or barriers. Refer to local safety standards for details of the clearances
required.
2.1.3 Inspection
Ensure that the unit and all leads are inspected for integrity and for signs of damage each time before
any testing is started.
Ensure the high voltage leads are carefully stored and that the exposed ends are kept clean, and that
the protective plastic cover is fitted over the connector.
The earth cable and the earth cable on the discharge/earthing probe are both made from a very flexible
copper conductor with transparent silicon insulation to allow visual inspection.

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2.2 Connection and Testing
2.2.1 Connection Sequence
WARNING - Ensure that all necessary safety procedures are followed at all times!
a. Connect earth lead between test object earth and PT18-10 earth terminal.
b. Connect discharge/earthing probe to the PT18-10 earth terminal. The earth hook on the probe
must now be placed on the test object HV connection point.
c. Connect the phases not being tested to earth. This means 1 phase for bipolar test and 2 phases
for a unipolar test.
d. For a unipolar test connect the black/negative HV lead to the negative output socket on the PT18-
10 and the test object. The positive output must be blanked off using the plastic blanking plug
provided (not the metal dust cap). It is also possible to carry out a positive unipolar test, as
shown in figure 3, although it is more common to use a negative test as this is more onerous.
e. For a bipolar test connect both the red/positive and black/negative HV leads to the output sockets
on the PT18-10 and the test object as shown in figure 4.
f. Connect the PT18-10 to mains supply.
h. Check that all connections are secure and that all safety procedures have been followed.
Re-check that all personnel are out of the test area.
2
8
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10
4
6
0
2
4
6
8
10
Mains
supply
Blanking plug
Connect to low
impedance
local earth
Cable under test
DP20 Discharge probe
Figure 2 Connections for positive unipolar test

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2
8
0
10
4
6
0
2
4
6
8
10
Blanking plug
Connect to low
impedance
local earth
Cable under test
Mains
supply
DP20 Discharge probe
Figure 3 Connections for negative unipolar test
2
8
0
10
4
6
0
2
4
6
8
10
Mains
supply
Connect to low
impedance
local earth
Cable under test
DP20 Discharge probe
Figure 4 Connections for bipolar test

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2.2.2 Testing Sequence:
WARNING
a. Check that all connections are secure and that all safety procedures have been followed.
Re-check that all personnel are out of the test area.
b. Remove the discharge/earthing probe from the test object.
c. Switch ON the supply to the PT18-10 using the key provided.
d. Ensure that the output control is at zero and press the RED HV ON push-button to switch on the
HV output. SLOWLY increase the output voltage until the desired test level is reached.
e. Hold the test voltage for the prescribed testing time.
f. At the end of the test time DO NOT SWITCH OFF THE HV OUTPUT, but return the voltage
regulator to the zero voltage position.
g. Observe the slow decay in the output voltage indicating a healthy cable.
h. After 30 seconds, discharge the cable. This may be achieved either using the DP20 discharge
probe or the internal dump circuit, depending on the level of energy stored in the cable. If the
DP20 is used when carrying out bipolar tests, ensure that both cable cores are discharged.
The internal discharge circuit is automatically engaged when the output is switched off.
g. Using the DP20 discharge probe tip discharge any remaining charge on the cable, then connect
the earthing hook on to the test terminal.
2.2.3 Disconnection Sequence:
WARNING
To disconnect repeat the connection sequence in the reverse order, ensuring that both sides of a
connection are earthed before breaking a connection. Maintain an earth on the test object after testing
to avoid problems with voltage recovery due to dielectric absorption.
REMEMBER!
ALWAYS CHECK EACH POINT ABOVE AND ENSURE THAT YOU ARE
FOLLOWING ALL APPLICABLE SAFETY PROCEDURES