Kohler 20-3250 kW manual TP-6200 10/12 Specifications and Features

Engine speed recovery depends upon characteristics such as engine make, fuel type, load types, and operating conditions. The underfrequency unload setting should match the engine speed recovery characteristics for the application.

Underfrequency Unload Slope. This setting determines how much the voltage drops during an underfrequency condition. Typically, applying a large electrical load causes a dip in engine speed and frequency. The voltage regulator reduces voltage, allowing engine speed recovery. The volts-per-Hz setting determines the amount of voltage drop.

Reactive Droop. Reactive droop compensation provides reactive current flow adjustment in the generator set during generator set-to-generator set paralleling applications. Reactive droop reduces excitation levels with increasing reactive current. A reduced excitation level reduces generator set reactive current or generated VARs, improving reactive load sharing.

Enter the gain setting as a percentage of system voltage when full-rated load with 0.8 power factor is applied. Any loads less than full load force the voltage to drop by the ratio of reactive volt-amps (VARs) to rated VARs.

VAR Control. VAR control is used in some utility paralleling applications. The excitation is regulated to maintain the reactive load rather than output voltage. The VAR adjust setting determines what reactive load is maintained at the generator set output. The VAR adjust is the total reactive load (sum of three phases).

VAR control allows the user to define the direction of the reactive current out of the generator set (generating) or into the generator set (absorbing).

The utility supply, not the controller, determines terminal voltage. Engine fueling determines real power, measured in watts, using load sharing module control.

Power Factor (PF) Adjust Control. Power factor control is used in some utility paralleling applications. The excitation is regulated to maintain PF rather than output voltage. The PF adjustment setting determines what PF is maintained at the generator set output. PF adjustment is the average of three phases.

Power factor is defined as the ratio of real power (watts) over the volt-amps. Power factor can be calculated as the cosine of the electrical angle between current and voltage. The cosine function is positive for angles between --90° and +90° including zero; and is negative for angles between --90 and +90 including 180°. This adjustment requires the user to determine whether the current leads or lags the voltage.

Regulator Gain. Regulator gain refers to the gain of the control system. Generally, the higher the gain the faster the system responds to changes and the lower the gain, the more stable the system.

If the voltage is slow the recover when loads are applied or removed, increase the regulator gain. If the voltage is unstable, decrease the regulator gain. Regulator gain is active only while not in the VAR/PF mode.

VAR/PF Gain. The VAR/PF gain also refers to the gain of the control system. Unlike the regulator gain, the response and stability of the system refers to the reactive current, or more specifically the VARs and/or power factor.

If the system is slow to recover to the desired VAR or PF setting, increase the VAR/PF gain. If the VARs or PF of the system is unstable, decrease the VAR/PF gain. Because VAR/PF stability can be effected by the prime mover (engine), VAR/PF gain adjustments should be coordinated with the load sharing adjustment.

Analog Voltage Adjust. Use Menu 11 to enable or disable analog voltage adjust. Analog voltage adjust is commonly used for active control of voltage by some external equipment in certain applications, like synchronizing.

Enabling analog voltage adjust allows slight adjustment to the operating voltage by use of auxiliary analog input #7. This input signal provides a bias to the voltage adjust value. The range of input voltage is 0--5 VDC nominal (0.1--4.9 actual). The corresponding range of bias is

±10% of nominal or system voltage. If the input voltage is at the midpoint (2.5 volts), the bias is zero and the voltage adjust value or regulation value will be equal to the system voltage. Likewise, if the input voltage is out of range (below 0.1 volt or above 4.9 volts), the bias will be zero. For every 1 volt of input voltage, the operating voltage will vary 4%; this satisfies the nominal ratio of

±10% output voltage for 0--5 volts input.

When analog voltage adjust is enabled, the description shown for Auxiliary Analog Input 7 is Analog Volt Adjust. Enable analog voltage adjust via KNET or MODBUS by setting the description for Analog Input 7 as Analog Volt Adjust.

Analog voltage adjust may be enabled only when the master switch is in the OFF/RESET or AUTO positions and while the generator is not running.

TP-6200 10/12 Section 1 Specifications and Features 31