• What is VacStat?
• What is the advantage of monitoring and detecting vacuum loss?
• Who installs VacStat?
• How do vacuum interrupters work?
• What usually causes a vacuum interrupter to fail?
• How does VacStat work?
• On what products can I get VacStat?
• Can I add VacStat to my existing switch?

What is VacStat?
VacStat is the only online loss of vacuum detection technology that provides real-time monitoring of vacuum integrity while switchgear is energized and in service.

What is the advantage of monitoring and detecting vacuum loss?
Current test methods rely on a periodic inspection to identify the vacuum integrity of the interrupter—at that moment in time. By monitoring vacuum levels continuously, a loss of vacuum can be immediately identified and corrective actions implemented. With this information at hand, operating and maintenance personnel have a reliable method to know the condition of the vacuum level at any given moment, saving time and possible equipment damage.

Who installs VacStat?
The current design requires that the VacStat be installed onto the vacuum interrupter during manufacturing. As a result, two installation options are currently available:

• Jennings Technology can work directly with a switch manufacturer to incorporate VacStat onto its vacuum interrupters.
• Jennings Technology can work directly with you and/or a trusted service provider to retrofit current switches with a VacStat vacuum interrupter.

How do vacuum interrupters work?
Vacuum interrupters are essentially circuit breakers that are designed for many applications in switchgear for medium voltage electrical power distribution systems. Vacuum  interrupters  interrupt electrical current from a few amperes up to 50 kA (50,000 amperes) and at voltage levels up to 72 kV ( 72,000 volts).

What usually causes a vacuum interrupter to fail?
Even though vacuum interrupters are very reliable devices, failures do occur. In order to properly function the level of vacuum must be in the order of 10-5 Torr or better. Loss of vacuum can be attributed to such causes as external degradation of dielectric properties, electrical puncture of the envelope, mechanical abuse, and bellows fatigue, just to name a few. All lead to the same effect: vacuum loss and failure to function.

How does VacStat work?
During manufacturing of the vacuum interrupter, a simple device is attached and completely sealed along with other parts of the interrupter. This device is used to monitor the vacuum inside the interrupter.  Then a fiber-optic signal is used to bring the information from the monitoring device to the low voltage section of the switch. This signal either notifies the user of the problem and/or electrically blocks operation of the switch or both depending upon the switch's application.

On what products can I get VacStat?
This technology is currently available with Joslyn Varmaster (VBM) or Transmaster (VBT) switches.

Can I add VacStat to my existing switch?
Since VacStat requires the monitoring device to be added to the vacuum interrupter, it can only be used on new vacuum interrupters and cannot be retrofitted.  However, selected switch manufacturers have opted to offer a switch conversion in which all vacuum interrupters will be replaced with vacuum interrupters that have VacStat installed.