B L A P O W E R P V T . L T D

WOODWARD 505 GOVERNOR VALVE / ACTUATOR

CALIBRATION &TEST

LALIT SINGHSr. EngineerC&I Dept.

WHY CALIBRATION/STROKE CHECKING REQUIRED

Before initial operation or after a turbine overhaul where any

actuator or valve

travel may have been affected, the below Valve Calibration

procedure should be

followed to insure that the 505 is correctly calibrated to the

turbine control

valve(s). When calibration is complete, 0 to 100% actuator

position as displayed

by the 505 must equal 0 to 100% actual valve travel.

BEFORE START PROCEDURE

Before calibrating or testing, the unit must be tripped and the steam

supply removed. This is to ensure that opening the control valve (s)

will not allow steam into the turbine. Overspeed sensing and its

relay are disabled during this process. Overspeeding the turbine

may cause damage to turbine and can cause severe injury or death

to personnel. STEAM TO THE TURBINE MUST BE SHUT OFF BY

OTHER MEANS DURING THIS PROCESS.

505 KEY PAD AND DISPLAY

IN WOODWARD STEP-1

The 505’s Emergency shutdown contact input must be closed or

jumpered throughout this procedure (All Turbine Trip

Interlock From DCS Side will by pass after that setting jumper as mention

below TB’s after that DCS will not be able to turbine trip)

JUMPERE DETAIL IN TSP PANEL

Jumper J1:- In TSP Panel DIT-1 & DIT-2 .

Jumper J2:- In TSP Panel DIT-5 & DIT-6

Jumper J3:- In TSP Panel DIT-7 & DIT-8

Jumper J4:- In TSP Panel DIT-11 & DIT-12

Jumper J5:- In TSP Panel DIT-13 & DIT-14

Jumper J6:- In TSP Panel DIT-17 & DIT-18

IN WOODWARD STEP-2

Execute a system RESET command (Press the 505 “Reset”

key)

Press the 505’s front panel “Emergency Shutdown” button.

Press the ‘ACT’ key then the SCROLL DOWN key until the

“Stroke Actuators - Dsbled, Steam Must be Off” message

appears. (Verify that the turbine’s steam supply has been

shutoff before by an external Trip and Throttle valve.)

IN WOODWARD STEP-3

Press the “YES” key (This will cause the screen to

display a “Stroke to Min - Enabled, Min Curr

Adjust *XX.XX” message).

Press the “YES” key to enable this mode or the

“Scroll Down Arrow” to step to the mode desired

IN WOODWARD STEP-4

Stroke to Min - Enabld, Min Curr Adjust * XXX.XX — Press YES

to force the actuator output to the minimum stop. The message will

display ‘At Min’ and the actuator output current will move to its

minimum setting. The minimum current value can be adjusted only

when the ‘at sign’ (@) is on the bottom line of the display. Press the

SELECT key to move the @ symbol between the top and bottom lines.

Press the ADJ UP or DOWN keys to change the 0% actuator current

level. Press the SCROLL DOWN ARROW to step the next desired

mode, or the “CLEAR” key twice to save changes, and exit Calibration

mode.

IN WOODWARD STEP-5

Stroke to Max - Enabld, Max Curr Adjust * XXX.XX— Press

YES to force the actuator output to the maximum stop. The message

will display ‘At Max’ and the actuator output current will move to its

maximum setting. The maximum current value can be adjusted only

when the ‘at sign’ (@) is on the bottom line of the display. Press the

SELECT key to move the @ symbol between the top and bottom

lines. Press the ADJ UP or DOWN keys to change the 100% actuator

current DOWN ARROW to step the next desired mode, or the

“CLEAR” key twice to save changes and exit Calibration mode.

IN WOODWARD STEP-6

Manually Adjust - Enabld, Stroke Valve XXX.XX — Press the ADJ UP, ADJ DOWN keys

from this screen to move the valve’s output current between 0-100% at a 5%/second rate.

This allows both the actuator and valve to be tested for binding, play, resolution, linearity,

and repeatability.

Press the “YES” key at any time to allow a setting to be directly ‘Entered’. The message

will display ‘Manual’ when the ENTER mode is allowed. When in the ‘Manual’ mode, press

the “ENTER” key, enter the setting desired, then press the “ENTER” key again. This will

step the actuator output to a specific position instantly. Press the “ADJ UP/DOWN” or “No”

keys at any time to switch back to the “Enabld” mode.

When calibration is complete, 0 to 100% valve position as displayed by the 505 must

equal 0 to 100% actual valve travel. Press the SCROLL DOWN ARROW to step the next

desired mode, or the “CLEAR” key twice to save changes and exit Calibration mode.

INFORMATION

Press the CLEAR key twice to permanently

save any minimum or maximum actuator

settings into the 505. If variables are tuned or

changed but not stored in EEPROM by pressing

the CLEAR key twice, then those changes will be

lost if power is removed from the control or if

the control receives a CPU reset.

FLOW CHART

SCREEN DETAIL

Screen 3 show only when the unit is shut down. Screen 4,5 and 6

show only when stroke actuator is set to yes .

The asterisk (*) denotes a tunable parameter . To adjust this

parameter , the “@” symbol must be on the display line containing

the asterisk . The @ symbol is moved with the selection key .

Note :- If change are made to min or max current values they

can be recoded on the program mode worksheet under the

“Driver Configuration” header .

STROKE ACTUATOR MESSAGES

MESSAGE MEANING

Dsbld Stroke actuators function is disabled

Enabld Stroke actuators function is enabled

At Min Actuator output is set to the minimum

value ( 0% )

At Max Actuator output is set to the maximum

value ( 100% )

Manual Actuator output is in manual mode

VOITH I/H CONVERTER OR CPC

Voith electro hydraulic I/H converters adjust hydraulic positioning

cylinders by means of a pilot valve. The positioning cylinders operate

a valve that controls the mass flow needed to drive machinery. Voith

I/H converters ensure very precise and highly dynamic control of the

mass flow.

I/H converters change a constant input pressure into a variable

output pressure. A standard 0/4 – 20 mA with respect to 2- 4 Kg/Cm2

O/P Hydraulic Pressure . The major components of the I/H converter

are a hydraulic unit and a force-controlled electromagnet.

WORKING PRINCIPALA set signal w = 4...20 mA generates a magnetic force FMag in the VRM, the limits of which can be

adjusted by means of the X0 and X1 potentiometers and which is then transmitted onto the control

piston via tappet. The hydraulic force FHyd being proportional to the output signal pressure PA acts

against this force. In the case of the two forces being equal, the control piston is positioned in the

“hydraulic center” as shown in fig. and the output signal pressure PA corresponds to the set signal.

In the “hydraulic center“ position the control piston performs minimum oscillating movements in

the area of the guiding edges P→PA and PA→T, in order to keep the output pressure PA on the value

set by FMag. When increasing the set signal and thus FMag from this condition, the control piston

position changes and thus connects the output pressure PA to the feed pressure P and blocks PA

towards the tank return line T1and T2. Now pressure PA will increase until the same has returned

the control piston to the “hydraulic center“ and PA corresponds to the new set signal. The spring

force FFed of the control spring generates a force-offset in order to guarantee the I/H converter

function for output pressures of approx. 0 bar, too.

FUNCTION

Solenoid-force control generates a magnetic force of FMag in a 24V d.c. solenoid.

This magnetic force is proportional to the 0/4 – 20 mA input signal , the limits are

configured using the X0 and X1 parameters. The electronic control, magnetic flux

measurement, engineering design of the magnet and the hydraulic pilot control

together form a dynamic functional unit that is practically free of hysteresis.

The control magnet applies the force FMag to the control piston. This in turn

counteracts hydraulic force FHydr as generated by the pressure at output A over the

cross-sectional area of the control piston .

As a result of this regulation, the output line of the actuator always receives the

exact required pressure and the oil quantity for positioning the steam or fuel valves.

CALIBRATION

Due to unintentional maladjustment of the parameters or changed operating

conditions, new setting of one or both parameters may become necessary. We

recommend to document adjustment of the parameters as well as the set values. The

parameters are adjusted by means of potentiometers X0 and X1.

X0 - With help of potentiometer X0 the minimum output pressure PA min is adjusted at

a set point of 4 mA. Pressure increase by turning the potentiometer clockwise.

X1 - With help of potentiometer X1 the maximum output pressure PA max is adjusted at

a set point of 20 mA. Pressure increase by turning the potentiometer clockwise.

Note:-X1 should be adjusted before X0. The X1- adjustment influences the

adjustment of X0

I/P CURRENT V/S O/P PRESSURE

S .N o.

I /P C omm.

(0-100% wrt 4-

20mA )

O /P P ress. K g/C m2

I nc.

O /P P ress. K g/C m2

D ec.

1 0 2 22 10 2.18 2.193 20 2.36 2.374 30 2.55 2.575 40 2.74 2.766 50 2.94 2.967 60 3.14 2.168 70 3.34 3.369 80 3.57 3.5710 90 3.76 3.7711 100 3.99 3.99

Thank You