PST: Programmable System Timer


  • Single or dual channel operation
  • Dual supply voltage
  • Quartz-controlled
  • 1ms resolution
  • 1000 second maximum time
  • Voltage, current & contact operation
  • Contact status indication
  • 6 digit LED display
  • Compact and portable

Product Data

The PST timing system provides commissioning and protection engineers with a simple to use and highly accurate timing system for all types of protective devices. The unit is based on the highly regarded timing systems used in the T&R current injection systems.

The unit has three trigger sources for starting and stopping timing: two contact inputs and one current input. The contact inputs accept either volt-free contacts or a dc voltage, and auto-select for normally open or normally closed contacts.

Timing Modes

Single Contact

The timer is started on the first change of state of contact set 1, and stopped on the second change of contact set 1.

Dual Contact

The timer starts on the first change of state of contact set 1 and stops on the first change of state of contact set 2.

Current Operated

Three current input ranges are available on the PST: 1A, 2.5A and 5A. The timer will start when the current exceeds 20% of the selected range (e.g. 1A on the 5A range) and stop when the current drops below 20%.