Basler Electric BE1-40Q - Manual (Page 18)

Figure 3-2. Phase Shift Example
The response of the relay is:
Front Panel Pickup Setting =
( ) ( )






°
− °






8 cos
8 sin
3
θ
B AB
I V
Or
( ) 







− °
°






=
θ
8 sin
8 cos 3 Setting Pickup Panel Front
AB
B
V
I
Where:
V
AB
= phase A to phase B voltage magnitude
I
B
= phase B current magnitude
Ө
= system power factor angle = (voltage angle)
– (current angle)
CURRENT SENSING
The monitored current is derived from the secondary of a system current transformer rated nominal five
amperes. An internal current transformer (CT) provides isolation and scaling for proper relay operation.
The front panel HI/LOW RANGE switch uses the tapped secondary of the internal CT for range selection
to increase pickup stability.
Note that when the connection plugs (paddles) are removed, the CT inputs are shorted.
HI/LOW RANGE SWITCH
The front panel HI/LOW RANGE switch selects which secondary winding of the internal CT is connected
to the TAP switch and thus the measurement circuitry. The position of this switch may be changed while
3-2 BE1-40Q Functional Description 9171500990 Rev N