ABB SA-1 Instruction Leaflet

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Page 1

ABB Automation, Inc.

Substation Automation & Protection Division Coral Springs, FL Allentown, PA

Instruction Leaflet

41-348.1H

Effective: November 1997 Supersedes I.L. I.L. 41-348.1G, Dated January 1985

( | ) Denotes Change Since Previous Issue

CAUTION

Before putting relays into service, operate the relay to check the electrical connections. Close red handle switch last when placing relay in service. Open red handle switch first when removing relay from service.

1. APPLICATION

The SA-1 relay is a three-phase high-speed relay used for differential protection of ac generators and motors. With proper selection of current transformers, the relay is unaffected by dc transients associated with asymmetrical through short-circuit conditions.

Current transformer burden in ohms should not exceed (N

should not differ by more than a 2 to 1 ratio between the two sets of ct’s. The above terms are defined as:

= proportion of total number of ct turns in

= current transformer relaying accuracy

= resistance of the burden, excluding ct

)/133; further, the burden factor, BF,

PVCL

use

class voltage (e.g. C400, V

NPV

1000

--------------------- -

winding resistance

= 400)

Type SA-1

Generator Differential Relay

In calculating the burden, use the longest one-way lead resistance from the ct to the SA-1 for distribution transformer or resistance grounded machines. Use twice the longest one-way lead resistance for reactance grounded machines.

For example, if the 400/5 tap of a 600/5 multi-ratio ct is used, N

rating, V

Assuming a resistance burden of R burden factor, BF is:

The other set of ct’s may than have a burden factor as high as 2 x 3.8 = 7.6, or as low as 1/2 x 3.8 = 1.9.

If the other set of ct’s also has a burden of 0.5 ohm, a C100, C200, or C400 rating would be satisfactory since the burden factors are 7.6, 3.8 and 1.9 respectively.

2. CONSTRUCTION

The type SA-1 relay consists of a Restraint Circuit, Operating Circuit, Sensing Circuit, Amplifier Circuit, Trip Circuit, Indicating Circuit, Surge Protection Circuit and external reactors. The principal parts of the relay and their location are shown in Figures 1 through 8.

= 400/600 = 0.67. If this ct has a C200

= 200, and the burden should not exceed:

NPV

------------------- -

133

1000

---------------------

NPV

0.67 200×

--------------------------- - 1.0 ohm== 133

= 0.5 ohms, the

1000 0.5×

--------------------------- - 3.8== =

0.67 200×

All possible contingencies which may arise during installation, operation or maintenance, and all details and variations of this equipment do not purport to be covered by these instructions. If further information is desired by purchaser regarding this particular installation, operation or maintenance of this equipment, the local ABB Power T&D Company Inc. representative should be contacted.

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41-348.1H

Type SA-1

Generator Differential Relay

2.1. RESTRAINT CIRCUIT

The restraint circuit of each phase consists of a center-tapped transformer, a resistor, and a full wave rectifier bridge. The outputs of all the rectifiers are connected in parallel. The parallel connection of rectifiers is a maximum voltage network. Hence, the voltage applied to the filter circuit is proportional to the phase current with the largest magnitude.

2.2. OPERATING CIRCUIT

The operating circuit consists of a transformer, a resistor, and a full wave rectifier bridge. The outputs of all the rectifiers are connected in parallel. This parallel connection of rectifiers is a maximum voltage network. Hence, the voltage applied to the filter circuit is proportional to the phase current with the largest magnitude.

2.3. SENSING CIRCUIT

The sensing circuit is connected to the output of the restraint filter circuit, the operating filter circuit and the input to the amplifier circuit.

With no gate current flowing, the thyristor acts as an open circuit to the breaker trip coil. When a gate current is applied tot he thyristor the thyristor connects the breaker trip coil to the dc supply.

2.6. INDICATING CIRCUIT

The indicating circuit is triggered by a signal from the amplifier of the relay. Under normal or non-fault conditions, the indicating circuit is turned off. When a fault is applied to the relay, the amplifier will conduct to cause a signal to flow into the indicator circuit. When the indicator circuit is triggered, the lamp will turn on. This lamp will remain lit until the indicator circuit is interrupted by resetting the micro-switch.

2.7. SURGE PROTECTION CIRCUIT

The surge protection circuit consists of two capacitors (C10 and C11) and a R-C network which is connected across the anode and cathode of the tripping thyristor to prevent the SCR from firing by a surge of voltage.

2.8. EXTERNAL REACTORS

2.4. AMPLIFIER CIRCUIT

The amplifier circuit consists of a two-transistor amplifier which controls the operation of a relaxation oscillator.

The amplifier circuit is connected to the sensing circuit such that it receives the difference in output of the restraint filter and the operating filter. Thus, the polarity of the input voltage to the amplifier depends upon the relative magnitude of the voltages appearing on the restraint and operating filters. When the voltage output of the operating filter is greater than the output voltage of the restraint filter, a voltage of a certain polarity appears across the input of the amplifier. To trigger the amplifier requires that the output voltage of the operating filter be greater than the output voltage of the restraint filter.

2.5. TRIP CIRCUIT

The trip circuit consists of a thyristor which has an anode, cathode, and a gate. The anode of the thyristor is connected to the positive side of the dc supply and the cathode of the thyristor is connected to the negative side of the dc supply through the trip coil of a breaker. The gate of the thyristor is connected to the output of the amplifier circuit through a pulse transformer.

Three reactors are mounted on a metal plate with a separate terminal strip. The reactors are of the saturable type.

3. OPERATION

The Type SA-1 relay is connected to the protected apparatus as shown in Figure 9. On external faults, current flows through the primary winding of the restraint transformers to induce a voltage on the restraint side of the sensing circuit. If the two sets of main current transformers have different performances, some current will flow out of the mid-tap of the restraint transformers to the operating transformers. This will produce a voltage on the operating side of the sensing circuit. With the relay correctly applied, sufficient restraint voltages will exist to prevent the operating voltage from triggering the amplifier.

The percentage slope characteristic of the relay limits the operating voltage on heavy external faults where the performance of the two sets of current transformers may be quite different.

On internal faults, the operating coil current is the sum of the current flowing in each of the windings of the restraint transformer and sufficient operating voltage is available to overcome the restraint voltage.

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Type SA-1 Generator Differential Relay

41-348.1H

4. CHARACTERISTICS

The percentage slope curves are shown in Figures 12 and 13. It will be observed that the relay operates at 5% unbalance at 5 amperes restraint (Figure 12) to provide high sensitivity for internal faults up to full load conditions. At 60 amperes restraint, the operating current required to trip the relay is 30 amperes or 50% unbalance (Figure 13). Thus, when 60 amperes through-fault current is flowing, the output of the main current transformers may vary considerably without causing incorrect operation.

The minimum pickup of the relay is 0.14 ampere or

0.5 ampere for the desensitized version.

The operating characteristic of the desensitized SA1 is shown in Figure 14.

The time curve of the relay is shown in Figure 15.

The frequency response characteristic of the SA-1 relay is shown in Figure 16.

6. SETTINGS

There are no taps on either transformer and, consequently, there are no settings to be made except for the choice of battery voltage level.

The 48/125 Vdc relays are normally shipped for 125 volts. For 48 Vdc applications use the mid-tap on the resistor mounted at the top of the relay. The red dot on the resistor is the common point – DO NOT REMOVE.

7. INSTALLATION

The relay should be mounted on switchboard panels or their equivalent in a location free from moisture. Mount the relay vertically by means of the four mounting holes on the flange for semi-flush mounting.

Either a mounting stud or the mounting screws may be utilized for grounding the relay. The electrical connections may be made directly to the terminals by means of screws.

5. ENERGY REQUIREMENTS

Each Restraint Circuit

Burden at 5 amperes is 0.25 VA Continuous rating 20 amperes 1 second rating 300 amperes

Operating Circuit

The burden imposed by the operating circuit on each circuit transformer is variable because of the saturating transformer and reactors. At 0.5 amperes, it is 0.37 VA, and at 60 amperes it is 170 VA.

Continuous rating 10 amperes 1 second rating 200 amperes

Amplifier

The dc burden on the station battery is:

Volts Milliamperes Watts

125 dc

48 dc

55 60

6.9

2.9

The external reactor assembly should be mounted and wired per “interwiring Connection Drawing”, Figure 11.

For detailed FT case information, refer to I.L. 41-

076.

8. ADJUSTMENTS AND MAINTENANCE

The proper adjustments to insure correct operation of this relay have been made at the factory and should not be disturbed after receipt by the customer.

8.1. ROUTINE TEST

The following check is recommended to insure that the relay is in proper working order. All checks can best be performed by connecting the relay per the test circuit of Figure 17. Due to high impedance of the external reactor, prior to saturation, the test circuit of Figure 17 should be used to test the relay only. The reactors can be checked by applying 0.2 amperes 60 hertz and reading the voltage drop across the reactor with a high impedance True RMS reading voltmeter. The voltage drop will be between 20 and 26 volts True RMS. For 0.4 amperes input, the reading should be between 29 and 31 volts True RMS.

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41-348.1H

Type SA-1

Generator Differential Relay

1. Minimum Trip Current with IR set at zero amperes, apply 0.14 ±5% (0.5 ±5% got desensi-

tized SA-1) amperes operating current to each operating circuit of the relay. The relay should operate and the indicator lamp should light.

2. Differential Characteristic a) Apply IR of 5 amperes and adjust the operat-

ing current until the relay operates. The relay should operate and the indicator lamp should light with an operating current of 0.25 ±5% amperes (0.71 5% for desensitized SA-1). Repeat for each phase of the relay.

b) Apply IR of 60 amperes and adjust the oper-

ating current until the relay operates. The relay should operate and the indicator lamp should light with an operating current of 30 ±10% amperes. Repeat for each phase of the relay. (IR = 40 amperes and IO = 24 ±10% for desensitized SA-1).

8.2. MAINTENANCE

All relays should be checked once a year to detect any failures which may have occurred. The tantalum capacitors C1, C2, C3, C4 and C13 may have a common mode failure characteristic and should be checked visually for symptoms of electrolyte leakage every year and replaced if necessary.

8.3. CALIBRATION

Use the following procedure for calibrating the relay if the relay adjustments have been disturbed. This procedure should not be used until it is apparent the relay is not in proper working order.

1. Minimum Trip Current – Connect the relay per test circuit of Figure 17 with switch K open. Adjust the operating resistor in the rear of the relay until the relay operates with IO equal to

0.14 ampere, 0.5 ampere for desensitized SA-1.

DO NOT make adjustments to the resistor unless the dc is disconnected.

The indicator lamp should light when the relay operates.

Repeat for each phase of the relay.

2. Percentage Slope Characteristic (Low Cur- rent). Close switch K and set IR equal to 5

amperes and adjust the restraint resistor in the rear of the relay until the relay operates with Io =

0.25 ±.010 amperes. DO NOT adjust resistor with dc applied to relay.

The indicator lamp should light when the relay operates.

Repeat for each phase of the relay.

Percentage Slope Characteristic (High Current) – Set IR equal to 60 amperes for the oper-

ating current of 30 amperes. Replace the resistor R17 if necessary. The value of R17 can be between 0 and 100 ohms. Repeat for the other two phases if necessary, replacing R18 and R19 respectively.

3. Electrical Checkpoints – See Table 1.

9. RENEWAL PARTS

Repair work can be done most satisfactorily at the factory. However, interchangeable parts can be furnished to customers who are equipped for doing repair work. When ordering parts, always give the nameplate data.

10.ELECTRICAL CHECKPOINTS

Connect relay per test circuit of Figure 17. All voltage readings should be made with a high resistance voltmeter. Refer to component location of checkpoints. Voltage readings are approximate. The voltage readings “Input to Amplifier” should not be taken with relay in service.

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Type SA-1 Generator Differential Relay

41-348.1H

Table 1:

(Values in Parenthesis Represent Desensitized SA-1)

CIRCUIT

Operating

Sensing

(Operating)

Restraint

Sensing

(Restraint)

PRIMARY

CURRENT PHASE

0.14A (0.5A)

1 2 3

Any

0.14A

phase

(0.5)

Any

30.0A

phase

5.0A 1 2 3

Any

5.0A

phase

CHECKPOINTS (Typical Value)

TERMINAL VALUE FUNCTION

2 - 7 3 - 6 4 - 5

2.5 ac

Input to operate rectiﬁer Input to operate rectiﬁer Input to operate rectiﬁer

+ to 23 - 26 24 - 26

24 - 8 8 - 25

25 - 26

2.1 dc

1.85 dc

0.55 dc

0.65 dc

Output to rectiﬁer a. Output to operating sensing circuit b. Input to ampliﬁer c. d. Output to restraint sensing circuit

Ref.: a = b + c + d

+ to 24 - 26 51.0 dc

18 - 13 17 - 14 15 - 16

6.0 ac

Input to restraint rectiﬁer Input to restraint rectiﬁer Input to restraint rectiﬁer

+ to 25 - 26

25 - 8 8 - 24

24 - 26

2.1 dc

1.2 dc

0.6 dc

0.3 dc

a. Output of restraint sensing circuit b. c. Input to ampliﬁer d. Output to operating sensing circuit

Ref.: a = b + c + d

Ampliﬁer

60.0A

Minimum

Trip

Current

+5%

Any

phase

Any

phase

+ to 25 - 26 42.0 dc

+ to -

27 - 8 12 - 8 10 - 8

0.7 dc

24.0 dc

+ to -

27 - 8 12 - 8 21 - 8

0.5 dc

24.0 dc

10.0 dc

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41-348.1H

Type SA-1

Generator Differential Relay

Table 2:

Electrical Part List

Circuit Symbol Reference Style

Resistors Resistors Resistors Zener SCR Reactor

Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor

Capacitor Capacitor Capacitor Capacitor Capacitor Capacitor

UT, UM, UB LT, LM, LB R14 Z2

60 Ohms, 25W 265 Ohms, 25W

1.8K, 40 W IN2986B

1875676 1725542 187A321H06 629A798H03 184A614H05

1478B98G01

SA Module Style Number 408C673G01 Sub 35

R1 R2 R3, R4 R5 R6 R7 R8 R9 R10 R11 R12 R13

†

R17, R18, R19 C1, C2, C3, C13

C4 C5 C6 C7 C8, C9

270 Ohms, 1W 2K, 5% 15K, 5%

2.7K, 5% 68K, 5% 27K, 5%

2.2K, 5% 100 Ohms, 10% 220 Ohms, 5% 680 Ohms, 5% 47K, 5% 33 Ohms, 5%

25 MFD, 125V 22 MFD, 35V

0.5 MFD, 200V

2.2 MFD, 35V

2.0 MFD, 200V

0.47 MFD, 50V

184A635H06 184A763H34 184A763H55 184A763H37 184A763H71 184A763H61 184A763H35 184A763H03 184A763H11 184A763H23 184A763H67 187A290H13

184A637H01 184A661H16 187A624H03 837A241H16 187A624H05 762A680H04

Diode Diode

Zener SCR Transistor Transistor Transformer

D1 to D24 D25, D26

Z1 T1, T2

T3 TR-1

IN4821 IN645A

IN752A K1149-13 2N3417 2N2647

188A342H16 837A692H04

186A797H12 184A640H13 848A851H02 629A435H01 629A372H02

SPK Module Style Number 1584C21G01

Resistor Capacitor Capacitor

†

NOTE: The values of R17, R18 and R19 are between 0 and 100 Ohms. They are determined in test.

R15 C10, C11 C12

470 Ohms, 1W

0.01 MFD, 1.5KV

2.0 MFD, 200V

187A643H19 3516A36H03 3509A33H01

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Type SA-1 Generator Differential Relay

41-348.1H

Figure 1. Type SA-1 Generator Differential Relay without Case (Front View)

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41-348.1H

Type SA-1

Generator Differential Relay

Figure 2. Type SA-1 Generator Differential Relay without Case (Rear View)

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Type SA-1 Generator Differential Relay

41-348.1H

Figure 3. Internal Schematic of Type SA-1 Relay 48/125 Vdc

629A406 Sub 15

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41-348.1H

Type SA-1

Generator Differential Relay

876A613 Sub 9

Figure 4. Internal Schematic of Type SA-1 Relay 250 Vdc

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Type SA-1 Generator Differential Relay

41-348.1H

(DESENSITIZED)

TYPE FT-32 CASE

FOR GENERATOR PROTECTION IN

RELAY TYPE SA-1 HIGH SPEED DIFFERENTIAL

Figure 5. Internal Schematic of Desensitized SA-1 Relay

877A847 Sub 8

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41-348.1H

R17

Type SA-1

Generator Differential Relay

762A601 Sub 9

Figure 6. Component Location for 48/125 Vdc

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Type SA-1 Generator Differential Relay

41-348.1H

Denotes Change

867A639 * Sub 5

Figure 7. Component Location for 250 Vdc

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41-348.1H

Type SA-1

Generator Differential Relay

COMPONENT LOCATION

48/125 V

1 1

C11 & C10 .01 uf 3516A36H03

C11 & C10 .01 uf 3516A36H03 C12 2.0 uf 3509A33H01

C12 2.0 uf 3509A33H01 R15 470 Ohm 187A643H19

R15 470 Ohm 187A643H19

R15

C12

SPK 1584C01G01

COMPONENT LOCATION

250 V

1 1

R15

6 7

SPK 1584C01G02

C11 & C10 .01 uf 3516A36H03 R15 470 Ohm 187A643H19

Illustration

3532A07 Sub 2

Figure 8. Component Location of the SPK Module

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Type SA-1 Generator Differential Relay

41-348.1H

Figure 9. External Schematic of Type SA-1 Relay for Generator Protection

775B965 *Sub 4

Figure 10. Reactor Outline

775B982 Sub 1

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41-348.1H

Type SA-1

Generator Differential Relay

NOTE: A - PLACE IT. 1 TO 3 IN IT. 5 FOR SHIPPING

Lead

IT.

1 3.00 .164 - 32 .164 - 32 2 4.00 .164 - 32 .190 - 32 3 3.00 .164 - 32 .190 - 32 4 13.438 .164 - 32 .190 - 32

SCREW SIZE

Figure 11. Relay and Reactor Interconnection

Denotes Change

±.156

PART

ITEM

NAME 01 LEAD 57Z0301 616 A 63-D-653 2 02 LEAD 57Z0401 622 A 63-D-655 3 03 LEAD 57Z0301 622 A 63-D-655 1 05 BAG 836A618 H04 B 27-D-5478 1

STYLE

DWG.

ITEM

GR.

NOTE CODE

ENG.

REF. REQ

775B981 * Sub 5

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Type SA-1 Generator Differential Relay

41-348.1H

Figure 12. Percentage Slope characteristic at Low Value of Restraint Current

3537A44 Sub 2

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41-348.1H

Type SA-1

Generator Differential Relay

878A742 Sub 3

Figure 13. Percentage Slope Characteristic at High Value of Restraint Current

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Type SA-1 Generator Differential Relay

41-348.1H

Figure 14. Percentage Slope Characteristic of High Value Restraint Current for Desensitized SA-1 Relay

619406 Sub 1

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41-348.1H

Type SA-1

Generator Differential Relay

477706 Sub 1

Figure 15. Typical Operation Time Characteristic

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Type SA-1 Generator Differential Relay

41-348.1H

3537A45 Sub 2

Figure 16. Typical Frequency Response Curve

Figure 17. Typical Frequency Response Curve

184A864 Sub 4

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41-348.1H

Type SA-1

Generator Differential Relay

Denotes Change

3519A69 * Sub 4

Figure 18. Outline and Drilling Plan for the Type SA-1 Relay in Type FT-32 Case

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Type SA-1 Generator Differential Relay

41-348.1H

NOTES

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41-348.1H

Type SA-1

Generator Differential Relay

ABB Automation, Inc.

Substation Automation & Protection Division 4300 Coral Ridge Drive Coral Springs, FL 33065 954 752-6700 800 523-2620

❖

www.abb.com/papd

ABB Automation, Inc.

Substation Automation & Protection Division 7036 Snowdrift Road, Suite 2 Allentown, PA 18106 610 395-7333 800 634-6005