There are many variations on this remote tripping scheme. Some utilities simply allow the
transformer MOAB to open without the use of a ground switch. This presupposes that a heavy
fault will be seen by the remote relays, and their breakers will trip before the MOAB blades open. If
the fault cannot be seen by the remote relays the fault current is low and the MOAB will probably
not be damaged. It is possible, of course, that the switch will be damaged anyway, but the cost
savings by not providing the ground switch and its associated controls may justify the risk. If there
are communication channels available, transfer trip schemes similar to those discussed in Chapter 6
can be used.