• ±18kVdc output voltage (PT18-10)
  ±30kVdc output voltage (PT30-10)
• 10mA output capability.
• Both voltage and current metered
  on HV outputs.
• Automatic earth system for dumping
  capacitive loads.
• HV output plug & socket system.
• Key operated supply switch to prevent unauthorized operation.
• Zero-volt interlock.
• Visual indication of test piece failure.

Product Description
T&R Test Equipment is a market leader in the field of protection test equipment. The range includes primary and secondary current injection equipment up 6000A, voltage sources, micro-ohmmeters and high voltage test systems up to 100kV.

The PT18-10 and PT30-10 high voltage dc test sets are designed to perform tests on installed cable and jointing systems. The units have a variable output voltage with a maximum or ±18kVdc (PT18-10) or ±30kVdc (PT30-10). Both units have a maximum charging capability of 10mA. A zero-volt interlock is fitted that prevents the output being switched on unless the output control is at zero.

The units include an automatic load discharge system that discharges the cable under test when the output is switched off or a breakdown occurs. The internal dumping system can discharge a maximum of 2.5kJ on each output, corresponding to 10mF at 18kV or 4mF at 30kV. In the event of a test object failure, the overload circuit will automatically switch off the output voltage and earth the output via the internal discharge circuit. A manual discharge probe is also supplied as standard with both units, allowing higher load capacitances to be safely discharged.

The output voltage is metered by two large, linear, analogue instruments marked 0-20kV (PT18-10) or 0-30kV (PT30-10). Test object current is metered by two further analogue instruments with 0-10 scale marking. The meters read 0-10mA directly, or 0-1mA when the ¸10 push button is operated.

The HV output from the unit uses a high quality plug and socket system, allowing for easy cable replacement.

Output
All of the PT series cable test systems have high quality high voltage output connectors, and are supplied with
detachable, partially screened output cables.

Metering
The positive and negative output voltages on the PT series are metered on the HV output by separate analogue instruments.

The output current on both of the outputs is metered by a dual range analogue instrument. The 1mA range is
selected by the ÷10 pushbutton adjacent to the mA meter.

Overload Protection
The PT18-10 and PT30-10 are protected by an overload trip on the output that operates at 12mA.

Load Discharge System
The PT18-10 and PT30-10 are fitted with an automatic internal load discharge system that grounds the load via a 20kW resistor on each output when the output is switched off. The discharge system is rated to dissipate 2.5kJ once every 15 minutes on each output. The PT18-10 can discharge a maximum load capacitance of 10mF per output from 18kV, and the PT30-10 can discharge a maximum load capacitance of 4mF per output from 30kV.