Basler BE1-60 Voltage Balance Relay Setting Test

0: No power status output, optional 1 is with power status output.

C: Output test button with push to test button.

2: Auxiliary output type, normally closed (NC) auxiliary contact, one for each circuit.

F: Shell form, semi embedded installation.

When selecting, it is important to pay attention to whether the input voltage level and wiring method (star or delta) are consistent with the on-site PT; The output contact form (normally open/normally closed) needs to meet the requirements of the interlocking circuit (usually requiring normally closed series connection to the trip circuit); The control power supply voltage needs to match the on-site DC or AC power supply.

Key points for installation wiring and grounding

BE1-60 adopts S1 chassis and supports semi embedded or protruding installation. The installation dimensions and panel opening diagram are detailed in the manual (in inches and millimeters). Due to the solid-state design of the relay, there are no special restrictions on the installation angle.

Key Wiring Guide:

Voltage input terminal: According to the induction input type (A~F), connect the two three-phase voltages to the corresponding terminal blocks according to Figure 4-8 in the manual. For example, a three-phase star input needs to be connected to the A, B, C phases and neutral point (if any), while a delta input needs to be connected to the line voltage.

Output contact: The main output (loop 1 and loop 2) is usually used for trip locking or alarm. If used for blocking overcurrent relays, the normally closed contacts should be connected in series in the overcurrent relay trip outlet circuit.

Auxiliary power supply: The power terminals have no polarity, but it is necessary to ensure that the voltage is within the allowable range. When the power supply is normal, the green LED on the panel lights up.

Grounding: A copper wire of not less than 12 AWG must be used to reliably connect the grounding terminal of the enclosure to the ground grid, and it is recommended that each device be independently led to avoid common ground interference.

Important precautions:

If the output contact drives the external relay coil, it is recommended to parallel reverse diodes at both ends of the coil to suppress EMI interference.

If insulation withstand voltage testing is required, the connecting plug must be unplugged and the relay must be removed from the chassis first, otherwise it may damage the internal electronic components.

Setting strategy and typical settings

The only user setting component for BE1-60 is the ten level differential setting switch on the panel, corresponding to 5% to 50% rated voltage, with a step size of 5%. Reasonable tuning should take into account the following factors:

The inherent deviation of the two PTs during normal operation: Due to the fact that the power PT and measurement PT may be taken from different positions, there may be a 2% to 5% difference in their secondary voltage during load changes. For example, when the generator is fully loaded, the power PT voltage may be 5% lower than when it is unloaded, so the set value should be greater than the maximum normal deviation, usually taking 10% to 15% as the starting point.

For E/F type input (single-phase synthesis): Due to internal averaging processing, the actual sensitivity is reduced. It is recommended to use a lower gear (such as B=10% or C=15%), otherwise single-phase disconnection may not be detected.

Coordination with other protections in the system: If used to block voltage controlled overcurrent relays, it is necessary to ensure that BE1-60 can send a blocking signal before the overcurrent relay acts when the voltage drop caused by PT disconnection reaches the set value. Due to the BE1-60 action time being less than 150ms, which is much faster than the timing or inverse time limit of the overcurrent relay, it usually meets the coordination requirements.

Example calculation: Assuming the rated voltage of the system is 120Vac and the normal voltage difference between the power PT and the measured PT does not exceed 8%, the setting switch can be set to C (15%) or D (20%), leaving sufficient margin. If using E/F type input, it is recommended to place it at B (10%), because the equivalent difference synthesized internally during single-phase disconnection is only one-third of the actual phase voltage difference (such as the 40V synthesized difference mentioned above). If placed at G (42V), it may not function.

On site testing and functional verification

After new installation or maintenance, it is recommended to perform functional testing according to the following steps to verify that the relay wiring is correct and the setting is reasonable.

Required instruments: Adjustable three-phase or single-phase AC voltage source (accuracy ± 1%), multimeter, timer.

6.1 Basic Actions and Reset Test (Taking Three Phase Star Input as an Example)

Set the difference setting switch to the lowest gear A (5%).

Apply rated voltage (such as 120Vac line voltage) to both inputs, wait for the state to stabilize, confirm that both output relays are in normal state (normally closed type is closed, normally open type is open), and reset the target indicator (if any).