AVR Comparision

A V R COMPARISION CHART

SX 460 SX 440 SX 421 MX 341 MX 321

Used on m/cs from 30-200 KVA, Used on m/cs from 210-650 KVA, Used on m/cs from 210-650 KVA Used on m/cs from 30-650 KVA Used on m/cs from 725 KVA UC frame machine. HC4 & HC5 frame machines. HC4 & HC5 frame machines. I.e. UC22,27 & HC4, HC5 frame & above I.e. HC6 & HC7 frame

m/cs with PMG as optional. machines.

2 phase sensing. 2 phase sensing. 3 phase sensing. 2 phase sensing. 3 phase sensing terminals 6,7,8 from Isolation Transformer

Terminal 7,8 from main stator are, Terminal 7,8 sensing & power Terminals 6, 7,8 sensing & power input from main Stator Terminal 7,8 sensing I/p from main stator & Secondary & power input from PMG. Power & sensing input for AVR. input from main stator of m/c to AVR. of m/c to AVR. Power input from PMG to AVR.

Power - Connect 7 , 8 from main Power - Connect 7 & 8 from main Power - Connect 6, 7, 8 from main Stator to Power - Connect P2 , P3 from PMG Power - Connect P2, P3, P4 from PMG stator to 7 , 8 of AVR. stator to P3 & P2 of AVR. P4, P3, P2 of AVR respectively. to P2 , P3 of AVR respectively. to P2, P3, P4 of AVR respectively.

respectively.

Sensing - Connect 7, 8 from main Sensing - Connect 7 & 8 from main Sensing - Connect 6, 7, 8 from main stator to, Sensing - Connect 7 & 8 from main Stator to Sensing - Connect 6, 7, 8 from Isolation Transformer stator to 7, 8 of AVR. stator to 3 & 2 of AVR respectively. 6, 7, 8 of AVR terminals respectively. 3 & 2 of AVR respectively. secondary to 6, 7, 8 of AVR respectively.

AVR DC output X, XX OR F1 F2, AVR DC output X, XX OR F1 F2 AVR DC output X, XX OR F1 F2 AVR DC output X, XX OR F1 F2

to Exciter Stator ( I.e. +ve, - ve ) AVR DC output X, XX OR F1 F2 to Exciter Stator ( I.e. +ve, - ve ) to Exciter Stator ( I.e. +ve, - ve ). to Exciter Stator ( I.e. +ve, - ve ) respectively. to Exciter Stator ( I.e. +ve, - ve )

Used with SELF EXCITED, Used with SELF EXCITED MACHINE Used with SELF EXCITED MACHINE Used with SEPARATELY EXCITED MACHINE Used with SEPARATELY EXCITED MACHINE

non PMG machine. WITHOUT PMG. WITHOUT PMG. WITH PMG. WITH PMG.

Excitation Interruption link, K1, K2, Excitation interruption link K1, K2 Excitation interruption link K1, K2 Excitation interruption link K1, K2 provided. Excitation interruption link K1, K2

not provided. provided. NO EXTERNAL SHORT LINK. NO EXTERNAL SHORT LINK.

( Always short externally ) K1, K2 control thru B0, B1 coil supply control. ( Always short externally ) K1, K2 control thru B0, B1 coil supply control. During High excitation, coil at B0, B1 activates & opens link at During High excitation, coil at B0, B1 activates & opens K1 , K2 thus interrupts excitation. link at K1 , K2 thus interrupts excitation.

Stability selection Stability selection Stability selection

Frame UC 22, HC 4,5 - Link BC Stability selection - Frame UC 22, HC 4,5 - Link BC Frame UC 22, HC 4,5 Stability selection - N. A. ( 90 KW - 550 KW ) Under 40 KW - Link B D ( 90 KW - 550 KW ) ( Under 90 KW ) - Link AC

40 KW - 90 KW - Link A C

Frame UC 27, HC 6,7 - Link A,B 90 KW - 550 KW - Link B C Frame UC 27, HC 6,7 - Link A,B ( 90 KW to 550 KW ) - Link BC

( Over 550 KW ) Over 550 KW - Link A B ( Over 550 KW ) Frame UC 27, HC 6,7-

( Above 550 KW ) - Link AB. Frequency selection Frequency selection

Frequency selection - Frequency selection Frequency selection 4 Pole 50 HZ - LINK - 2 , 3. 4 Pole 50 HZ - LINK - 2 , 3.

50 HZ - LINK C - 50. 50 HZ - LINK C - 50 50 HZ - LINK C - 50 4 Pole 60 HZ - LINK - 1 , 3 4 Pole 60 HZ - LINK - 1 , 3

60 HZ - LINK C - 60. 60 HZ - LINK C - 60 60 HZ - LINK C - 60 6 Pole 50 HZ - - NO LINK 6 Pole 50 HZ - - NO LINK 6 Pole 60 HZ - - Link 1 , 2. 6 Pole 60 HZ - LINK - 1 , 2. External Hand Trimmer for,- External Hand Trimmer for,- External Hand Trimmer for,- External Hand Trimmer External Hand Trimmer REMOTE VOLTAGE ADJUSTMENT. REMOTE VOLTAGE ADJUSTMENT REMOTE VOLTAGE ADJUSTMENT REMOTE VOLTAGE ADJUSTMENT REMOTE VOLTAGE ADJUSTMENT No Trimmer - Link 1 , 2. No Trimmer - Link 1 , 2. No Trimmer - Link 1 , 2. No Trimmer - Link 1 , 2. No Trimmer - Link 1 , 2. For Trimmer - Remove Link at 1,2 For Trimmer - Remove Link at For Trimmer - Remove Link at 1 , 2 & connect For Trimmer - Remove Link at 1 , 2 For Trimmer - Remove Link at 1, 2 & connect trimmer here. 1 , 2 & connect Trimmer here. & connect Trimmer here. & connect Trimmer here.

Trimmer here.

TRIMMER - 1 K Ohm / 1 Watt. TRIMMER - 1 K Ohm / 1 Watt TRIMMER - 1 K Ohm / 1 Watt TRIMMER - 4.7 or 5 K Ohm / 1 Watt TRIMMER - 4.7 or 5 K Ohm / 1 Watt AVR input selection

-220 / 240 V input - No Link. AVR input selection,- AVR input selection - N. A.

High Voltage. AVR input selection AVR input selection - N. A. Link 2 - 3, 4 - 5, 6 - 7 at AVR.

110 / 120 V input - Link 3 , 4. Link 2 - 3, 4 - 5, 6 - 7 at AVR. Low Voltage.

For 415V output machine, NO LINK AT 3,4 IS REQUIRED.

Terminals for Parallel Operation with Grid. NOT SUITABLE FOR Terminals A1, A2 used only in Terminals A1, A2 used only in Terminals A1, A2 used only in

PARALLEL OPERATION. parallel operation with grid. parallel operation with grid. parallel operation with grid. ( S1 - S2 ) - U / ( S1 - S2 ) - V / ( S1 - S2 ) W & A1, A2 Wires from Power Factor Controller Wires from Power Factor Controller Wires from Power Factor Controller

need to be connected to A1, A2. need to be connected to A1, A2. need to be connected to A1, A2.

NORMALLY KEEP OPEN. NORMALLY KEEP OPEN. NORMALLY KEEP OPEN. NORMALLY KEEP OPEN.

Parallel operation :- Parallel operation :- Parallel operation :- Parallel operation

:-S1 , S2 terminals of Droop CT provided at S1 , S2 terminals of Droop CT provided at S1 , S2 terminals of Droop CT provided at S1 , S2 terminals of Droop CT provided at W phase of machine need to be connected at W phase of machine need to be connected at W phase of machine need to be connected at W phase of machine need to be connected at S1 , S2 terminals of AVR respectively. S1 , S2 terminals of AVR respectively. S1 , S2 terminals of AVR respectively. S1 , S2 terminals of AVR respectively. S1, S2 terminal of AVR are of Voltage Droop. S1, S2 terminal of AVR are of Voltage Droop. S1, S2 terminal of AVR are of Voltage Droop. S1, S2 terminal of AVR are of Voltage Droop.

Over Voltage Protection - N. A. Over Voltage Protection - N. A. Over Voltage Protection :- Over Voltage Protection - N. A. Over Voltage Protection

AVR SETTING POTS & ADJUSTMENT PROCEDURES.

POTS

AVR TYPE

PURPOSE

RAMP

MX 321

To control time taken by generator to build up voltage

from initial to rated.

STABILITY

SX 460

SX 440

To prevent voltage hunting ( fluctuation )

SX 421

I.e. to provide damping effect.

MX 341

MX 321

VOLTS

SX 460

To adjust generator output voltage.

SX 440

MX 341

OVER

SX 421

Over Voltage Protection.

VOLTAGE

MX 321

To remove generator excitation in event of

loss of AVR sensing input.

SX 421 - Priovides only tripping signal for overvoltage

Additional tripping circuit need to provide.

MX 321 - It has internal de excitation system

& also provides signal to use for tripping

external circuit as Circuit Breaker.

Incorrect setting LED will glow.

EXCITATION MX 341

AVR detects high excitation & removes it after

TRIP

MX 321

predetermined time 8 - 10 sec.

Only for m/cs

with PMG

UFRO

SX 460

SX 440

To set under Frequency Roll Off Point.

SX 421

All AVR's are incorporated with under speed protection

MX 341

MX 321

Incorrect setting - LED will remain permanently ON.

when generator is ON LOAD.

DIP

SX 421

Adjusts slope of voltage /speed ( HZ ) characteristic

MX 341

below the knee point.

MX 321

DWELL

MX 321

To maintain time delay between recovery of voltage

and speed.

Dwell time delay is to reduce generator KW below

available engine KW to allow improved speed recovery.

PROCEDURE

Standard Ramp time - 3 sec. - Factory set.

can be reduced to - 1 sec. - Fully anticlockwise.

can be increased to - 8 second - Fully clockwise.

* Clockwise rotation of the pot increases damping effect

and vice versa.

Clockwise rotation of the pot increases output voltage

and vice versa.

Correct setting is 240 V across AVR terminal E1& E0.

* Run the DG set on No Load at 1500 RPM.

* Turn overvoltage pot fully clockwise.

* Set output voltage of machine to 480 V with Volts pot.

* Turn Overvoltage pot slowly anticlockwise.

* At one point output voltage will collapse.

This is correct point of setting.

* Now turn Volts pot anticlockwise and stop DG set.

* Restart DG set & run to 1500 RPM on no load.

* Set output voltage of machine to 415 V with Volts pot.

* Now overvoltage setting is set.

* Now max. Overvoltage limit is 480 V.

LED will remain permanently ON during Excitation Trip.

PMG being separate source for excitation supply, it can deliver max excitation during

large overload or shortcircuit. This may cause to overvoltage and burn the winding.

Hence to protect winding, Excitation trip protection is provided.

* Put generator off.

* Remove short link at K1, K2 of AVR & connect 5A switch there.

* Turn I limit pot fully anticlockwise.

* Short all main stator winding at terminals & put clamp on Ammeter there.

* Switch at K1, K2 keep open and start the generating set.

* Close across K1, K2 & turn I limit clockwise until required current limit observed

on the clamp on meter.

* As soon as required current limit reads, open the K1, K2 switch.

If current collapses during procedure,

-* Shut down set & open K1, K2 switch.

* Restart set for 10 min with K1, K2 open to cool generator winding.

Running set for cooling without K1, K2 open may lead to damage the set.

Clockwise rotation reduces speed ( Frequency ) setting of KNEE POINT and LED

becomes off.

LED should on if frequency falls below 47 HZ ( on 50 HZ Generator )

Setting procedure

:-* Run DG on no load at 1425 RPM.

* Turn UFRO pot fully anticlockwise, LED will become off. M/c vtg. Will be 415 V.

* Now start turning UFRO pot slowly clockwise.

* At one point LED will glow and voltage will drop down slightly.

* Turn the UFRO pot slightly anticlockwise and LED will become off.

* Again turn UFRO pot clockwise and LED will glow.

* Now increase speed of engine to 1435 - 1440 RPM & LED will become off.

* Now UFRO is set at 47.5 HZ.

NOTE : for MX 341 & MX 321 if LED is glowing & no output voltage is present

checkup with Excitation Trip and / or Overvoltage setting.

Clockwise adjustment of the pot increases dip in voltage and vice versa.