KEPCO BOP 5-20DL, Operator'S Manual

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2-8
BOP 5-20DL 081915
2.7.2 LOAD CONNECTION, REMOTE SENSING
The basic interconnections between the BOP and the load using remote sensing are shown in
Figure 2-7 (using the rear panel) and Figure 2-8 (using the front panel). This is the recom-
mended load connection for all applications requiring minimum load effect across a remote load.
A twisted or shielded pair of wires (No. 22 AWG minimum) are connected from the BOP sensing
terminals to the load. For the BOP 5-20DL this remote error sensing technique will compensate
for load wire voltage drops up to 0.25 volts per wire.
NOTE: Observe polarities: the COMMON sensing wire must go to the COMMON load wire,
the OUTPUT sensing wire must go to the OUTPUT load wire.
2.7.3 A-C GROUND
The metal cases of electronic equipment which are operated from the a-c power line must be
kept at ground potential at all times. If the 3-wire line cord with 3-prong safety plug (supplied
with this equipment) is used in combination with a properly grounded a c power outlet, this is
taken care of automatically. If a non-grounded outlet is used, the case must be grounded sepa-
rately. A separate GROUND terminal is provided for this purpose on the front panel as well as
on the rear of the BOP.
The GROUND terminal is connected to chassis of the unit and to the local earth-ground poten-
tial through the A-C power line cord. It can be used a) as a grounding point for the output of the
unit, and b) for doubling the a-c power cord earth-ground connection if necessary by providing a
separate connection to the local earth-ground point.
2.7.4 D-C GROUND
Specified ripple and noise figures listed in Table 1-3 for operational power supplies are valid only
with the COMMON side of the output/load circuit returned to an earth-ground point as shown in
Figures 2-5 through 2-8.
CAUTION: If the programming device return is tied to earth-ground, leave the BOP out-
put floating. Otherwise, instability and inaccuracy will occur, especially if the
programming device return connection is lost.
CAUTION: Do not connect both the load and the programming device return (common)
to earth-ground potential and do not use the programming return terminal as
a tap point for the load return. Otherwise part of the BOP output current (all
current if the COMMON power connection between the BOP and the load is
lost) will flow inside the BOP along the programming signal return path,
resulting in damage to the unit.
If the application requires, the COMMON of the BOP may be floated up to 500V d-c (or peak) off
ground. For this case, due to the common mode noise current flowing through a higher imped-
ance, the resulting ripple/noise will be larger than published specifications. If the application
must be grounded, connect a single return/common point of the application (including program-
ming device, BOP and load) to earth-ground. The exact location of the best return earth-ground
point must be carefully selected for minimum ripple/noise output.
The GROUNDING NETWORK terminal is tied to GROUND (chassis) terminal through a series
capacitor-resistor network. Connecting the GROUNDING NETWORK terminal to the COMMON
terminal reduces common noise current flowing through the load and, if a BIT card is installed, it
ensures that the dynamic swing of the output does not affect the digital section.
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