Basler BE1-32R/32O/U Direction Power Relay Setting and Testing Guide

Guidelines for Setting and Testing Basler BE1-32R/32O/U Direction Power Relays

In power plants, industrial self owned power stations, and new energy grid connected systems, directional power relays are key protective devices to prevent damage to the prime mover and avoid system reverse power accidents. The Basler BE1-32R (over power/reverse power) and BE1-32O/U (over power+under power) series solid-state relays, with their wide range tuning, high precision, and flexible time curves, have long served steam turbines, water turbines, diesel generators, and grid interconnection nodes. However, on-site engineers often face problems such as confusion in model selection, mismatch between setting parameters and operating conditions, and unfamiliarity with testing methods. This article is based on the complete technical manual of this series of relays, systematically sorting out its core functions, setting logic, testing verification, and typical fault response from the perspective of engineering application, helping maintenance personnel quickly grasp the essentials of using this protection device.

Product positioning and model identification

BE1-32R is a directional over power relay that can detect excessive power flow along the "trip direction", typically used for generator reverse power protection (reverse power transmission). BE1-32O/U integrates both over power and under power detection functions, suitable for applications that require simultaneous monitoring of power upper and lower limits, such as start stop control in combined power generation systems or load monitoring of interconnected lines.

Model recognition relies on the "Style Number" code on the panel, which consists of multiple digits and letters, respectively defining:

Sensor input type (A/B/C/D/E/V, corresponding to single-phase/three-phase, phase voltage/line voltage combination)

Rated frequency (50/60 Hz)

Output contact form (normally open/normally closed)

Time characteristics (instantaneous, timed, inverse time)

Auxiliary contact and target indicator options

Engineers must verify the CT/PT polarity, phase rotation, and required time curve of the original system when replacing old relays or building new projects, otherwise it may result in misoperation or refusal to operate.

Typical application scenarios and tuning logic

2.1 Generator reverse power protection (reverse electric operation)

When the steam turbine loses its original power (such as when the main steam valve is closed), the generator remains tied to the power grid and will operate as an electric motor, absorbing active power from the system to drive the rotor. This' reverse power 'state is particularly dangerous for steam turbines - the lack of steam cooling can cause blade overheating and deformation. The manual provides the reverse power tolerance threshold for different prime movers:

Water turbine: 0.2%~2.0% of rated kW

Steam turbine (condensing or back pressure): 0.5%~3.0%

Diesel engine (no combustion): up to 25%

Gas turbine: up to 50% (due to compressor losses)

During actual tuning, the over power (reverse) starting value of BE1-32R is usually set as low as possible, with steam turbines generally not exceeding 3% and diesel/gas turbines not exceeding 10%. To avoid misoperation caused by transient impact during grid connection, it is necessary to cooperate with a fixed time delay (typically 2-10 seconds, or even more than 30 seconds). The manual clearly states that this relay is not suitable when the power factor is below 0.10, and the manufacturer needs to be contacted for a specialized solution.

2.2 Cogen Start Stop Control

In the cogeneration system, BE1-32O/U can simultaneously achieve "start" and "stop" signals:

Start logic: Monitor the input power of the mains power. When the power exceeds the set value (such as excessive mains load), the over power output is closed, triggering the automatic start and networking of the backup generator.

Shutdown logic: When the generator takes on the load, the mains power decreases; When the mains power is lower than a certain threshold (such as set to 50% of the overcurrent setting value), the low-power unit outputs a shutdown signal after delay, causing the generator to stop running.

This application requires precise setting of the underpower percentage (adjustable from 10% to 95%) and sufficient delay (several minutes) to avoid frequent start stop caused by load fluctuations.

2.3 Circuit breaker tripping detection and interconnection line protection

In industrial power distribution, multiple incoming lines come from the same substation, or there is a local power source connected in parallel with the mains power. When one of the circuit breakers accidentally disconnects, it may cause overload or unexpected power flow in the remaining lines. BE1-32 relay can detect changes in power direction:

During normal operation, the power direction is located in the first and second quadrants (positive or reactive power flow).

When a certain circuit is disconnected, the local generator sends electricity back to the grid, and the power direction shifts to the third or fourth quadrant. At this time, the relay acts and trips the corresponding circuit breaker.

This application is extremely sensitive to phase rotation, especially for relays that use B, E, or V-type sensing (single-phase current+line voltage). When wiring, it is necessary to strictly follow the ABC or ACB phase sequence, otherwise the power direction discrimination will be completely incorrect.

Key electrical parameters and selection verification

3.1 Current and Voltage Input Range

CT secondary current: 5A (50/60Hz). Different sensing input ranges (1~9) correspond to different continuous/short-time heat resistance capabilities. For example, the continuous rating of ranges 1, 4, and 7 is 7A, while that of ranges 2, 3, 5, 6, 8, and 9 is 10A. The site needs to confirm that the CT thermal capacity matches the relay.

Voltage input: PT secondary side 100/120V (50/60Hz), continuous withstand voltage 150% rated, power consumption<1VA.

3.2 Power Setting Range (Refer to Table 1-4 in the Manual)

Taking the common 120V, 1-phase (Type A/B/V) as an example:

Low range (Switch Lo): 0.5~5.0W (taps A~K correspond to 0.5, 1.0, 1.5... 5.0)

High range (Switch Hi): 2.0~20.0W (corresponding to taps 2, 4, 6... 20)

In addition, there are medium range (20~200W, 100~1000W, etc.) corresponding to higher voltage or three-phase connections.

For three-phase 120V (Type C/D/E), multiply the set value by the corresponding coefficient (such as three times), and refer to the testing section for the specific formula.

3.3 Time Characteristics

Instantaneous: Overpower response<80ms (60Hz)/<100ms (50Hz), underpower<50ms/65ms.

Time limit: By using two dials (0.1~9.9 seconds) in combination with x0.1 or x1.0 multiplier switches, a delay of 0.1~99 seconds can be achieved. Setting it to "00" means instantaneous.

Inverse time limit (only over power): The curve is selected by the dial numbers (01~99), and the typical curve is shown in Figure 1-15. The action time is inversely proportional to the multiple of "power/setting value", which is suitable for situations that require coordination with downstream fuses or circuit breakers.

Front panel control and operation guide

Familiarity with panel layout (Figure 2-1) is the foundation for quick tuning. The main control components include:

Range selection switch (A): Select the high/low range of over power.

Overpower tap selector (C): The rotary switch corresponds to taps A~K, and the starting power value is determined by matching the range.

Overpower delay dial (B) and multiplier switch (E): Set the time limit or inverse time limit curve number.

Underpower setting potentiometer (G): The adjustable range is 10%~95% of the over power setting value, increasing by a percentage counterclockwise.

Underpower delay dial (F) and multiplier switch (J): only time limited, no inverse time limit.

Indicator lights: Over power/Under power start indicator (LED), power indicator.

Target reset switch (K): The target indicator light for resetting the electronic latch, with a red LED as the target, remains in a state after power loss (restored after power supply is restored).

Output test button (N): The output relay can be manually triggered by pressing it with an insulating rod for circuit inspection.

Operation prompt: If the relay is instantaneous, there is no delay dial or multiplier switch; If it is an inverse time type, the delay dial is used to select the curve number rather than the number of seconds.

Practical steps for on-site testing and calibration

Section 5 of the manual provides detailed testing methods, now refined as the "four step method", suitable for regular calibration or verification before installation and operation.

5.1 Testing Wiring

Select the corresponding test connection diagram (Figure 5-1~5-5) based on the sensing type (A/B/C/D/E/V). Core principles:

Use a single-phase or three-phase power source (or analog source), apply voltage to the corresponding terminal, and connect the current source in series to the CT circuit.

If a three-phase source is lacking, a single-phase source can be used in parallel simulation, but the power reading needs to be corrected according to the formula (see the notes in each figure).

5.2 Overpower start-up value and return coefficient test

Set range to "low", tap to "B", delay to "00" (instantaneous), underpower knob all counterclockwise (to shield underpower).

Apply the rated voltage and slowly increase the current until the over power indicator light is on. Record the reading (or calculated value) of the wattmeter at this time, which should be equal to ± 2% of the power value corresponding to the panel tap (power factor 1.0).

Slowly reduce the current and record the power at the moment when the indicator light goes out, which should be about 98% of the starting value (with a return coefficient of about 0.98).

Repeat taps E and K for verification.

5.3 Under Power Start and Return

Set the underpower knob all clockwise (i.e. set to 95% of the over-power value), delay the instant, and select the over-power tap (such as B).

First, increase the current to exceed the underpower setting point, then slowly decrease the current until the underpower light is on. The recorded power value should be equal to 95% ± 2% of the over power setting value (or 0.1W, whichever is greater).

Increase the current, and the power should be at the return value (approximately 105% of the starting value) when the light goes out.

5.4 Time Delay Verification

Time limit (over power): Set the delay to "01" and the multiplier to x0.1, apply a step current of twice the set value, measure the time from current application to output contact action, which should be 0.1s ± 0.05s. Try again for "50" and "99" corresponding to 5.0s and 9.9s (tolerance ± 5%).

Fixed time limit (under power): Similar, but the starting signal is "current cutoff" (i.e. power drops suddenly from above the set point to below the set point), and a timer is used to measure the time from cutoff to contact action.

Inverse time limit (over power): Set the curve number (e.g. 05), apply different multiples of current (1.5 times, 4 times, 8 times), and verify the action time against the standard curve (e.g. about 0.46s ± 0.05s at 4 times).

Common fault phenomena and troubleshooting ideas

Possible causes and solutions for the fault phenomenon

The over power indicator light is not on, but the actual power far exceeds the set value. The polarity of the CT wiring is reversed, causing the power direction to be reversed; Or if the sensing type and wiring method do not match (such as Type B misconnected as Type A), use a phase meter to check the angle between current and voltage and confirm the power direction; Reconnect according to the internal wiring diagram (Figures 4-17~4-20)

Under power misoperation, especially when the load fluctuates slightly, the under power setting value is too high (close to normal load), or the delay is too short. Reduce the under power percentage (such as from 95% to 80%) and increase the delay (such as 5-10 seconds)

The contact output does not work, but the indicator light is on. The output contact is burnt or the intermediate relay coil is short circuited, resulting in insufficient contact capacity (DC inductive load requires a continuous current diode). Use a multimeter to check the output terminals (1-10 for over power, 2-10 for under power) for continuity; Confirm that the load current is within the rated range (DC<1A, AC<7.5A)

The target indicator does not light up or is lost after power loss. For electronic latch type targets, the state preservation after power loss depends on internal capacitors. If it is not powered on for a long time, it may fail; The current type target requires a circuit current of ≥ 200mA to trigger the target reset operation, which can be verified using the test button; If still ineffective, check the auxiliary power supply for power supply

The test button cannot be pressed, and a non-conductive rod (such as an insulated plastic rod) needs to be inserted into the front panel hole. It is not allowed to use metal objects and specialized insulation tools

Maintenance and storage precautions

Regular testing: It is recommended to perform a complete startup value, return coefficient, and delay verification every 1-2 years, and record the data for comparison with the factory values.

Grounding requirements: The relay housing must be directly grounded with a copper wire of not less than 12AWG, and cannot be connected in series with other equipment to ensure anti-interference ability and safety.

Storage and maintenance: There is an electrolytic capacitor inside. If it is stored as a spare for a long time, it should be powered on for 30 minutes every year to maintain the performance of the capacitor and prevent leakage or capacity loss.

Repair notice: The circuit board cannot be replaced on site. If an internal fault occurs, the entire machine should be returned to the factory for repair (contact Basler technical support to obtain a repair number). Spare parts can be pre prepared with "drawer units" of the same model for easy and quick replacement.

Typical replacement scenarios and selection alternatives

When using electromechanical directional power relays from GE, Westinghouse, or ABB on site, when replacing them with BE1-32 series, attention should be paid to:

Confirm the original CT/PT ratio and polarity, and adjust it to the range of the relay.

Electromechanical relays usually have a fixed delay, while BE1-32 provides flexible adjustment that needs to be readjusted according to the protection coordination curve.

If the original relay includes additional functions such as undervoltage and overvoltage, corresponding relays need to be configured separately, as BE1-32 only focuses on power.

In addition, if the on-site power factor is often lower than 0.10 (such as during no-load transformer charging), the relay is not suitable and Basler's specialized low power factor products should be used instead.