BankGuard PLUS
S&C Electric Company
Control
Proprietary Information
10
Operation
1011-540 5-17-04
Figure 2
Capacitor Unit Power Frequency Overvoltage versus Time
(IEEE Standard 18-1992)
Automatic Control Features
The BankGuard PLUS control device includes all the automatic features described in this
section.
Bank/Reactor Lockout and Alarm
The lockout logic includes a user-selectable time delay (0.2 to 30 second). The time
delay insures that the fuse for the failing capacitor unit operates before the control
device locks out the bank. This lets you readily locate the failed capacitor unit.
The BankGuard PLUS Automatic Control Device includes a standard alarm function,
which provides an alarm signal (after a time delay) upon the loss of fewer capacitor
units than that corresponding to the lockout level setting. For many capacitor banks it
is practical to activate the alarm at the loss of a single capacitor unit. This is a decided
advantage since replacement of the failed capacitor unit can be accomplished at a
convenient, planned time, instead of on an urgent basis during a lockout resulting from
Voltage on Capacitor Unit,
Per Unit of Nameplate Voltage Rating
T
im
e
, seconds
