BE1-32R, BE1-32R O/U
5
SPECIFICATIONS
(continued)
If sensing input range 2, 3, 5, 6, 8 or 9 is selected, the
input transformers are capable of 10 A continuous
current, 15 A for 1 minute and 200 A for 1 second.
Maximum burden for each current input (2 terminals) is
1 VA at threshold over the frequency range of 45 to
65 Hz.
Voltage Sensing
System potential transformers (PTs) with 120 or 240V
secondaries supply the Directional Power Relay’s input
transformers with single or three-phase voltages. The
voltage sensing inputs are nominally rated at 100 or
220V (50 Hz) and 120 or 240V (60 Hz) with a maximum
burden of 1 VA per input (2 terminals) over the fre-
quency range of 45 to 65 Hz.
SENSING INPUT TYPES
There are 6 sensing input types as defined by the Style
Chart (page 12). The Directional Power Relay’s input
circuitry receives voltage and current signals from
system PTs and CTs. The CT signal is adjusted in level
by a front panel range switch before it is applied to the
kW transducer circuitry. Several input circuit configura-
tions are available, the selection of which is determined
by the specific application. The following paragraphs
provide a brief description of each input sensing type
and their calibration
Type A Sensing: Single-Phase (Figure 7). The type A
sensing configuration monitors line-to-neutral voltage
and a single phase current of a three-phase, four-wire
circuit and calculates the power flowing in the tripping
direction. Relays with this sensing type are calibrated in
single-phase watts.
Type B (60 Hz) or Type V (50 Hz) Sensing: Single-Phase
(Figure 8) with 30° phase shift. This sensing configuration
monitors a line-to-line voltage and a single phase current
of a three-phase, three-wire circuit and calculates the
power flowing in the tripping direction. Since the input
voltage leads the input current by 30° (assuming unity
power factor) a 30° lagging phase shift network is de-
signed into the voltage input circuit. Relays with this
sensing type are calibrated in single-phase watts. Note:
Type B or V configurations are phase rotation sensitive.
Type C Sensing: Three-phase Scott Tee (Figure 9). The
type C sensing configuration monitors three line-to-line
voltages and a single phase current of a three-phase,
three-wire circuit and calculates the power flowing in the
tripping direction. The relay measures actual power even
if the system voltages are not balanced. Relays with this
sensing type are calibrated in three-phase watts.
Figure 7 - Single Phase, Type A Sensing
Figure 9 - Three Phase, Type C Sensing
Figure 8 - Single Phase, Type B or V Sensing
