Section 75
00-02-0522
04-06-11 -
19 -
8. Grounded CT’s
- The energy monitoring board allows termination of the CT
’
s in two
ways. The CT
’
s may be wired with both leads from each CT brought back to the EMB, or by
bringing one lead from each CT, tying the other leads together, and grounding them. This is
called grounded or commoned CT
’
s. If your installation can bring all six leads back to the
EMB, that is the method that we recommend. If the application can
’
t, and the CT
’
s have
one lead from each CT all tied together, then this selection needs to be set to "YES".
a. No (Default)
b. Yes
9. Nominal Voltage Source
- Allows selection of display voltage as line-to-line or line to
neutral.
a. Line - Line (Default)
b. Line - Neutral
10. Indicate Reverse Power
- Allows user to mask CT orientation alarms by disabling reverse
power/current indication
a. Yes (Default)
b. No
11. Phase Selection
- Common generator configurations.
a. 3Ph High Wye
b. 3Ph Low Wye
c. 3Ph Wye (Default)
d. 3Ph Delta
e. Center Tap Delta
f. Single
Phase
There are a number of ways to connect AC to the iGUARD. It is important to understand the
options and their meaning.
In the case of alternators that can be reconnected, the AC voltage and current are measured
at the non-neutral junction of the coils, and if “3ph high wye” is selected the coils are
connected in series. The actual output voltage will be 480 VAC, but the voltage measured at
the coil junction will be 240 VAC. The reading must be multiplied by 2 to display the output
voltage correctly.
In the case of a “3ph low wye”, the AC voltage and current are still measured at the non-
neutral junction of the coils, but the coils are arranged in parallel. The AC voltage output is 240
VAC but, the current is twice the reading from the CT.
When using a non-reconnectable alternator or the application doesn
’
t include a voltage
output select switch, “3ph wye” displays output voltage and output current directly (default
setting).
Phase-out
/ Discontinued
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