Basler BE1-27 Manual - page 10
BE1-32R, BE1-320/U
APPLICATION
PURPOSE
The BE1-32R Directional Overpower Relay and the BE1 -
32 0/U, Directional Over/Underpower Relays sense real
power flow (EI cos
0).
These relays are solid-state devices
designed for use in single-phase or three-phase systems
to provide equipment protection for overpower and/or
underpower or to be used for supervisory control of
circuits. Both relay configurations may be used to
monitor either forward or reverse power. In the following
application examples, single-phase connections are
shown for simplicity.
APPLICATION EXAMPLES
The BE1-32 relays (R and 0/U) are typically used in
applications where excessive power flow in the tripping
direction is indicative of undesirable situations. Typical
examples are discussed below:
EXAMPLE 1 - ANTI MOTORING
In this example, the power relay is used to protect the
prime mover rather than the generator. When an ac
generator, operating in parallel with a power system,
loses prime mover torque, it remains in synchronism with
the system and continues to run as a synchronous motor
drawing sufficient power from the system to drive the
z
0
w
a:
c
Cl
z
;;:
Q.
52
GENERATOR
TRIP
BE1-32R
WITH
E1
TIMING
Figure
1
-
Power Relay Motoring Protection
2
prime mover. Sustained motoring can cause severe
damage to the prime mover. The Directional Power
Relay, with its wide sensitivity range, can detect levels of
reverse real power flow as low as 0.5 Watts secondary
and provide an alarm or trip the unit off line (See Figure
1). In this example, single phase sensing is usually
considered sufficient, since motoring is a balanced
condition.
EXAMPLE 2- COGENERATOR CONTROL
Given that a co-generation system has automatic engine
controls, auto synchronizer, and automatic kW and kVar
controls, the system will virtually operate by itself. The
only functions not readily apparent are the start/stop
signals to the generators. Two system configurations
using a Power Relay may be utilized to generate contact
closures for start and/or stop signals.
The first configuration (Figure 2) shows a power relay
connected to the utility to sense kW. The pickup point of
the relay is set at the maximum desired utility power
level. If the power relay contact closes, the generator will
be started and automatically paralleled with the utility
system. A time delay of 15 seconds or more is generally
included in the "start" circuit to ignore transient overload
conditions.
52
BE1-32R
WITH
E1
TIMING
START
SIGNAL
ENGINE
CONTROL
Figure
2
-
Power Relay Start Control
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