Why is the Versa-Tech designed the way it is, such a departure from what we would normally see with the core standard recloser design?
When the Versa-Tech was first introduced into the marketplace in the summer of 2007, it was a very different type of product since it had an energized live tank device. At the time, this was really a departure from what was normally done with regards to the recloser design. This introduced a new school of thought to the industry, creating two schools of thought when it comes to recloser design-- one a dead tank and the other a live tank.
In the case of a dead tank recloser
design, we have a high voltage switch cabinet, which typically is at the top of
the pool. And that is tethered down into a control cabinet, which houses
typically not only the brains of the device, but also the power to operate the
device and any communications for remote access to the device. This
cabinet, as well as the switch itself, must be grounded solidly. To satisfy the
power requirements of the recloser control and operation, the control cabinet
needs to have auxiliary power source such as a battery and external transformer.
Thus, in such a scenario, we have a difference in potential between the switch
and the control cabinet.
Unfortunately, there are times where a
difference in potential, such as lightning storms, can become an issue. And it
is not out of the ordinary for sensitive electronics, such as those found
inside control cabinets for reclosers, capacitor banks, or load break switches,
to be inoperable in those types of circumstances. This is simply because the
electronics are in the path to ground, and they rely on transformer power and
backup power to operate.
The departure from the norm with the Versa-Tech
was to have the control function elevated to the same potential as the switch
itself and rather than have a control cabinet that was tethered to ground at
the base of the pole. This was achieved by incorporating the control inside the
housing of the switch. So, now, both the switch and the control function are at
the same potential as the system, which greatly reduces the effects of
lightning. In other words, it increases the lightning immunity.
The dielectric failures also are reduced
considerably because we have this bird on a wire concept in the case of the
Versa-Tech. In addition to that, there is no external auxiliary power required
because it is being power directly from the line current or fault current that is
present at that given time. There is no need for a control cabinet to be placed
at the base of the pole, much less being powered, as well.
The fact that there is less equipment
to install makes the installation much quicker compared to conventional dead
tank recloser. This also translates to system cost savings and reduction in
time and even materials that need to be used for the installation.