Woodward easYgen-2500-5/P1 8440-1884

Woodward  easYgen-2500-5/P1 8440-1884

A generator system that is connected to the load through a 3

phase, 4-wire connection but have the device wired for a 3-phase,

3-wire installation may have the L2 phase grounded on the secon

dary side. In this application the device will be configured for 3

phase, 4-wire OD for correct power measurement.

Power Factor is defined as a ratio of the real power to apparent

power. In a purely resistive circuit, the voltage and current wave

forms are instep resulting in a ratio or power factor of 1.00 (often

referred to as unity).

In an inductive circuit the current lags behind the voltage waveform

resulting in usable power (real power) and unusable power (reac

tive power). This results in a positive ratio or lagging power factor

(i.e. 0.85lagging).

In a capacitive circuit the current waveform leads the voltage wave

form resulting in usable power (real power) and unusable power

(reactive power). This results in a negative ratio or a leading power

factor (i.e. 0.85leading)

Inductive Capacitive

Load type Electrical load whose current waveform lags the

voltage waveform thus having a lagging power

factor. Some inductive loads such as electric motors

have a large startup current requirement resulting in

lagging power factors.

Electrical load whose current waveform leads the

voltage waveform thus having a leading power

factor. Some capacitive loads such as capacitor

banks or buried cable result in leading power fac

tors.

Different power factor

display on the unit

i0.91 (inductive)

lg.91 (lagging)

c0.93 (capacitive)

ld.93 (leading)

Reactive power display

on the unit

70 kvar (positive)-60 kvar (negative)

Output of the interface + (positive)- (negative)

Current relation to

voltage

Lagging Leading

Generator state Overexcited Underexcited

Control signal If the control unit is equipped with a power factor controller while in parallel with the utility:

A voltage lower “-” signal is output as long as the

measured value is “more inductive” than the refer

ence setpoint

Example: measured = i0.91; setpoint = i0.95

A voltage raise “+” signal is output as long as the

measured value is “more capacitive” than the refer

ence setpoint

Example: measured = c0.91; setpoint = c0.95

Discrete inputs may be configured to normally open (N.O.) or nor

mally closed (N.C.) states.

Fig. 57: Discrete inputs – state N.O.

In the state N.O., no potential is present during normal operation; if

an alarm is issued or control operation is performed, the input is

energized.

Fig. 58: Discrete inputs – state N.C.

In the state N.C., a potential is continuously present during normal

operation; if an alarm is issued or control operation is performed,

the input is de-energized

The N.O. or N.C. contacts may be connected to the signal terminal

as well as to the ground terminal of the discrete input ( Ä “Sche

matic and terminal assignment” on page 73).

It is recommended to use two-pole analog senders. This ensures

an accuracy of ≤ 1 % for 0 to 500 Ohm inputs and ≤ 1.2 % for 0 to

20 mA inputs.

The following senders may be used for the analog inputs:

n 0 to 20 mA

n Resistive (0 to 500 Ohm)

n VDO, 0 to 180 Ohm; 0 to 5 bar, Index “III”; 0 to 10 bar, Index

“IV”

n VDO, 0 to 380 Ohm; 40 to 120°, Index “92-027-004; 50 to 125°,

Index “92-027-006