Generator Automatic Voltage Regulator Instruction Manual
1. Description
KR440 Voltage Regulator (AVR) is a sealed electronic device that adjusts the rectified output power of the exciter armature by
controlling the low-power exciter magnetic field, so as to achieve the control host.
Magnetic field current, stable output voltage requirements of brushless generator, with low frequency and no input signal
protection device. It is also equipped with parallel compensation function, which meets the needs of customers to expand capacity.
2. Specifications
Input power: 170V ~ 265VAC, 50/ 60Hz
Detection power: 190V~270VAC 340~520VAC 50/60
Maximum output: 4A 95VDC
Voltage regulation rate: ≤0.5%.
Generator Field Resistance: 15 ohms minimum.
External potentiometer: 1KQ 1/2W potentiometer ±8%.
Voltage build-up (initial stage):
When the residual magnetism voltage is greater than 5V25Hz, the voltage will be established automatically. The low-frequency
protection has a built-in protection circuit that reduces the output voltage when the engine speed decreases (refer to Figure 3)
Operating temperature: -40 C~60 C.
Size: 163mmL*138mmW*45mmH
3. Precautions when using
1. Precautions during installation: (Refer to Figure 1 for configuration)
The installation, connection and inspection shall be carried out by persons with professional knowledge. The regulator shall be
installed in the generator in a place where it is protected from moisture and corrosion and is not easily touched by others. Under
normal operating conditions, the surface temperature of the regulator will exceed 60c. During operation, please do not touch the
heat sink of the regulator. Warning signs have been posted.
4. Adjustment
1. Low frequency adjustment (U/F).
When using at 50Hz, insert the "cross-line" between C, 50 (factory setting), when using at 60Hz, insert the "cross-line" between
C, 60. The U/F potentiometer is used to set the frequency action value of the low frequency protection. The setting steps: start
the engine and the voltage is established, and adjust the engine to the required low frequency value. Slowly adjust the U/F knob
to make the red indicator light on the AVR (factory setting is 47Hz at 50Hz, 57Hz at 60Hz). Its protection action is shown in
Figure 3 (when the red (LED) indicator light is on, it means that the frequency is insufficient. In this case, the output voltage
will drop due to the action of the low-frequency protection circuit to prevent excessive excitation current from damaging the
magnetic field stator coil).
2. Voltage adjustment (VOLT).
Adjust the "Voltage Potentiometer" to the rated value (increase clockwise). When using external voltage adjustment (please refer
to Figure 4), connect VR.IK1/2W between "1" and "2". When there is no external VR, "1" and "2" must be shorted.
3. Stability Adjustment (STAB).
Adjusting "Stable Adjustment" can make the output voltage of the generator stable, but excessive adjustment will make the
instantaneous voltage fluctuation rate of the generator increase under heavy load. It is recommended to run the generator set with
no load, check whether the speed is correct, and turn the potentiometer clockwise all the way, then slowly counterclockwise until
the generator voltage starts to fluctuate. The correct setting is to turn slightly clockwise from this position (ie at this point
the generator voltage is stable, but very close to the instability zone).
5. Excitation:
When the remanence of the generator is not enough to make the AVR build up the voltage, it can be excited by the outside, as shown
in Figure 2. After the engine is running, use a 12V battery, the negative pole is connected to the XX wiring column of the AVR,
The positive pole is connected to the AVR terminal X through a diode, and the excitation is stopped when the generator voltage is
established at 30 of the rated voltage. It is very important: (A diode must be used to ensure that the AVR is not damaged)
6. Wiring: (as shown in the figure)
1. K1, K2: are magnetic field switches, they must be short-circuited and cross-connected when not in use.
2. P2, P3: are the magnetic field power input terminals.
3.2, 3: It is the input terminal for detecting the power supply.
4.1, 2: It is an external VR, and it must be short-circuited when not in use.
5. X, XX: X is the magnetic field F+, XX is the magnetic field F-.
6. S1, S2: DROOP, CT input.
7. J1~J3: select]1+J2 jumper wire is 400V, J2+J3 jumper wire is 200V.
7. Parallel operation of generators
It is important to understand the following precautions for parallel operation when installing and setting up the differential
unit. When the generator is running in parallel with other generators or grid-connected, the most basic requirement is that the
generator has the same phase as the paralleled unit or grid.
order, and the following conditions must also be met.
1. The frequencies must be the same (minimum error allowed)
2. The voltage must be the same (minimum error allowed)
3. The voltage phase angle must be the same (minimum error allowed)
Please pay special attention:
1. When the parallel switch is closed, if the above three conditions are not met, it will cause excessive mechanical shock and
electrical shock to the generator.
flow shock and can cause damage to the device.
2. Active power is provided by the engine, and the characteristics of its governor determine the active power distribution among
parallel units.
3. The reactive power is provided by the generator, and its excitation control characteristics determine the distribution of
reactive power.
8. droop adjustment device (DROOP)
The most common method of allocating reactive power is to establish a voltage characteristic that decreases as the power factor
decreases (ie, the reactive power increases). This feature relies on a current transformer to feed back the phase angle (ie power
factor) of the current to the AVR. Depending on the load, the following settings should be used, and the following values are
based on rated current.
1. When the power factor is 0.8 (at rated current), the droop value needs to be set to 3%, and when the power factor is 0 (at
rated current), the droop value needs to be set to 5%, and turn the "droop adjustment" potential clockwise. to increase the sag.
Generally, when the power factor is zero at the rated current, the lower 5% is enough to meet the needs of no power distribution.
(Note 1. The current transformer must be installed in the output three-phase
One of the phases cannot be in the same phase as the detection power of the AVR. Note 2. It is very important to set all generator
voltages to the same value, as for the accuracy of droop regulation is secondary. Note 3. When a generator is running alone, if
the droop regulation is set to a power factor of 0.8 at full load, it cannot maintain the usual 0.5% voltage regulation.
Therefore, when running alone, the terminals SI-S 2 need to be short-circuited to restore the adjustment rate when running alone.
Note 4. The secondary side current of the current transformer matched with this AV R board is 1A-1.5A)
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