13
ABB
Figure 8: Transformer Tap and Ratio Chart
bushing, a potential device and a burden. Therefore,
since any one of these is not a perfect duplicate of any
other of its own kind, it is necessary to completely
re-adjust when any one of the combination is changed.
Auxiliary Winding
The output winding with terminals Z1, Z2 and Z3 is
designed for a maximum of 75 watts, and no more
than this amount of burden shall be connected to the
Z terminals, even though the total rating of the device
may be in excess of 75 watts in some cases.
Operating Tap Voltage
The primary of the device transformer is designed for
continuous operation at voltages not in excess of 7600
volts. Therefore, it is necessary to check the voltage
H2-H3 after any alteration to be certain this voltage
does not exceed 172V.
Adjustment-Need For
The adjustment of a potential device is in effect a
“tuning” procedure to affect a “match” between condenser
