Basler Electric BE3-81OT User Manual
Instructions
www.basler.com
+1 618.654.2341 (USA)
Model
BE3-81OT, BE3-81UT,
and BE3-81OT/UT
INTRODUCTION
BE3 frequency relays provide frequency monitoring and
protection in both single- and three-phase systems. They
are used in applications such as utility mains failure,
regulation of power supplies, and to protect generators
against over or underspeed. Underfrequency, over-
frequency, and combined under/overfrequency units are
available. BE3 frequency relays operate when the
adjustable trip point is reached. A time delay control is
provided with an adjustment of 0 to 10 seconds (relay
operating time is typically 200 ms). This time delay may be
used to prevent false tripping when there are slight
variations in the voltage supply. On overfrequency units, the
output relay energizes when the input signal exceeds the
trip point. On underfrequency units, the output relay de-
energizes when the input signal falls below the trip point. A
red LED indicates the state of the relay. A green LED
indicates the condition of the power supply.
SPECIFICATIONS
Operating Power
All units are self powered.
Nominal Voltage:
120 Vac, 240 Vac, 380 Vac,
or 480 Vac
Frequency:
50 Hz, 60 Hz, or 400 Hz
Burden:
<2.5 VA per phase
Overload:
1.25 times nominal continuously.
2 times nominal for 3 s.
Setpoint
Over/Underfrequency Set Range
50 Hz Nominal:
Adjustable 40 to 60 Hz
60 Hz Nominal:
Adjustable 50 to 70 Hz
400 Hz Nominal:
Adjustable 360 to 440 Hz
Setpoint range accuracy is
±3%.
Time Delay
Adjustable 0 to 10 s
Repeatability
Greater than 0.5% of full span
Differential
Fixed at 1% of nominal
Operating Time
200 ms typical
Output
Relay Type:
D.P.D.T.
AC Rating:
250 V, 5 A, non-resistive,
1,200 VA
DC Rating:
125 V, 1 A, resistive, 120 W
Mechanical Life:
5 million operations
Temperature
Operating Temperature:
0°C (32°F) to 60°C (140°F)
Functional Temperature: –25°C (–13°F) to 70°C (158°F)
Storage Temperature:
–40°C (–40°F) to 70°C (158°F)
Temperature Coefficient: 0.03% per °C (300 ppm/°C)
Humidity
Relative Humidity:
95% non-condensing
Physical
Mounting:
DIN rail 1.38” by 0.29” (35 mm by
7.5 mm)
Case:
Complies with IEC 529, DIN
40050, BS 5490
Case Material:
Complies with UL 94VO
Weight
Single Function:
0.88 lb (0.4 kg)
Multiple Function:
1.32 lb (0.6 kg)
Size
Single Function:
2.17” wide (55 mm)
Multiple Function:
3.93” wide (100 mm)
Agency
cULus listed to UL 508 and CSA C22.2 No. 14
CE compliant
GOST-R certified per the relevant standards of Gosstandart
of Russia
OPERATION
BE3-81OT and BE3-81UT frequency relays have two user-
adjustable controls marked SET and DELAY. The BE3-
81OT/UT has four controls: UNDER SET, OVER SET,
UNDER DELAY, and OVER DELAY. Each SET control
adjusts a relay trip point. An overfrequency trip causes the
relay output to energize when the frequency rises above the
SET threshold. An underfrequency trip causes the relay
output to de-energize when the frequency decreases below
the SET threshold. Refer to the setpoint specifications for
overfrequency and underfrequency adjustment ranges. Time
delay is the amount of time that elapses after the trip point is
reached and when the output relay operates.
Setting Example
A BE3-81OT relay with a nominal input rating of 60 Hz has
the following settings:
•
SET - 65 Hz
•
DELAY - 2 s
A trip occurs when the sensed frequency rises above 65
hertz and 2 seconds elapse. The relay resets when the
frequency decreases below 64.4 hertz (1% of nominal below
the setpoint).
Publication
9321800990
Revision
C
Instructions
Date
04/14
Copyright
2014