Hoyt Electrical Instrument Works, Inc. Alpha 40A Plus, Operating Manual

Page: 13 / 43

This screen will only appear
following the edit of system
type.
3.2.1.2 Potential Transformer
Primary Value
The nominal full scale voltage which will be displayed
as the
Line to Line
voltages for all system types.
The values displayed represent the voltage in
kilovolts
(note “K” symbol).
Pressing the “ ” key accepts
the present value and
advances to the “potential
Transformer secondary Value
Edit”
menu. (See Section
3.2.1.3)
Initially the “multiplier must be selected, pressing the
“ ” key will move the decimal point position to the
right until it reaches # # # #. after which it will return
to #. # # #.
Pressing the “ ” key accepts the present multiplier
(decimal point position) and advances to the
“potential Transformer primary Digit Edit” mode.
Note :
1. PT Values must be set as Line to Line
Voltage for Primary as Well as Secondary for all
system types (3P3W/3P4W/1P2W).
2. Default value is set as System Input Voltage.
Pressing the “ ” key sets the displayed
value and wil
l advance to “Potential Transformer
Primary Value Edit” menu. (See section 3.2.1.2)
Pressing the “ ” key will return to the system type
edit stage.
NOTE: Default value is set to ‘4’ i.e. 3P 4W.
Pressing the “ ” key will enter the system type edit
mode & scroll through the values available.
Pressing the “ ” key advances to the system
Pressing the “ ” key will enter the “Potential
Transformer Primary Value Edit” mode.
The PT Primary value can be set from 100 VL- L to
1200 kVL-L. The value will be forced to 100 VL-L
if set less than 100.
position, a steady decimal point will be present to
identify the scaling of the number until the cursor
position coincides with the steady decimal point
the “ ” key will advance to the “Potential Transformer
of 0.120 kV i.e. 120 Volts indicating steady decimal
position.
presently displayed Potential Transformer Primary
Value together with the Current Transformer Primary
Value, previously set, would result in a maximum
system power of greater than 3000 MVA (1000 MVA
per phase) in which case the digit range will be
restricted.
Pressing the “ ” key accepts the present value at
the cursor position and advances the cursor to the
Pressing the “ ” key
will scroll the value of the
through to 9 unless the
Potential Transformer Primary Digit Edit
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