SWSC Edition 2

fiompton 4 1/2 INCH SWITCHBOARD SYNCHRO CHECK RELAY

INSTRUMENTS AND LED SYNCHROSCOPE

FEATURES AND APPLICATIONS

* Precision LED Synchroscope * Visual indication of 'GEN' and

* Semi-automatic synchronising 'BUS'level

* Multi function * Voltage/phase angle & time

one case offers: delay controls

• Voltage difference indication * Synchronising between generators

• Phase difference indication or with existing busbar

• Voltage & phase synchronised * 'Dead-bus' option

relay * Compact 41/2 inch DIN Case

THECOMPANY

Crompton Instruments are leaders in instrumentation manufacture with over a century of experie nce in producing products to the highest in ternational standards . This worldwide market is supported by a netwo rk of Sales and Servic e Cent res and local distributors offering a wealth of expertise, ensuring total customer confidence.

T he company dates back to 1881 and now exports some 50% of its produ ction to over 50 countri es. Crom pton Instruments is a BS EN ISO 9001 1994 registered company and regularly suppl ies products to the world 's largest projects.

077-14L, 077-14G, 077-14D, 077-14H

THE OPERATION AS A SYNCHRO CHECK RELAY

T he 077- 14L and 077-i4G synch roscopes are based on a mlcrocontroller which interprets the input signals and displays the phase and voltage information on a series of light emmitting diodes (LEOs).

The model 077-14L requi res a nominal input voltage, i.e. 230V, whereas the model 077-14G operates over an input range, i. e. 220/240V.

T wenty four red LEOs are arranged in a ring simulating the traditional 360 0 analogue movement. Only one LEO is lit at anyone time indicating the phase diffe rence between the busbar (BUS) and generator (GEN) signals. This phase difference is calculated by measuring the time di fference between zero crossing po ints of th e two signal s and comparing it with the time period of the 'BUS' signal. This means that til e unit will operate correctly at any frequency within its range.

The voltage levels of th e two input signals are continuously measured and compared with the user adjustable voltage difference setting. If the measured difference is outside the allowable range, the red 'GEN' LED will be lit and if it is inside the range then the green 'GEN' LED will be lit. The ring of red LEOs will indicate the phase relationship provided the GEN level is above 76% of its nominal value.

Once the 'BUS' and 'GEN ' signals become coincident, the un it w ill wait for an adjustable ti me delay before lighting the green triangular SYNCHRONISED LEOs and operatin g t he relay . T he ring of LE Os is a lso extinguished which means the user will only see green LEOs when the generator 'GEN' is synchronised with the 'BUS'.

THE OPERATION AS A SYNCHRO CHECK RELAY WITH A 'DEAD' BUS FEATURE

The 077-140 and 077 -14H operates in the same way as the 077-14L and 077-14G synchro check relay with the add ition of a 'dead' bus feature which enables th e relay to energise with a 'GEN' supply only, thus allowing the generator to power th e 'BUS' during a supply failure.

The model 077-140 requires a nominal input range, ie 230V whereas the model 077-14H operates over an input range, ie 220/240V.

077-14A

1HE OPERATION AS A SYNCHROSCOPE

The 077-14A synchroscope provides illuminated indication of the actual phase difference between the generator 'GEN' voltage and the busbar 'BUS' voltage. If the LED display turns clockwise the generator frequency is too high and must be reduced and vise versa if the LED display turns anticlockwise.

Synchronising Practice SPECIFICATION If the time it takes to go through one cycle of 360° is T, ENCLOSURE then the frequency difference t,. f can be calculated from Designed to comply with: IECS1 (ANSI C39)

Safety requirements: IEC1 01 0-1 (300V ac RMS installation category III polution degree 2)

Case: Steel Dielectric Strength: 4kV rms for 1 minute Isolation: Bus/Generator/Relay output Enclosure Code: NEMA 3S NEMA 4 optional Vibration: To Lloyds shipping speCification INPUT Nominal Voltage: 63.S, 110, 120, 220, 230, 240,

3S0, 400, 41S, 440, 4S0, 220/240 (230 nominal) 3S0/4S0 (430 Nominal) volts ac or via VT

Burden: Maximum 4VA Frequency range: 40 to 6SHz Temperature range: Operational -10 deg C to 60°C

Storage -2SoC to +70°C Calibrated at 23°C

Humidity range: up to 95% (non-condensing) Adjustments Phase difference: + 0 to 20° Accuracy of setting + 1 ° Voltage difference: + 0 to 20% of nominal voltage

for all models except 077 -14G and 077-14H + 0 to 10% of nominal for model 077-14G and 077-14H

Accuracy of setting +2% Time delay: oto 2.5 seconds Accuracy of setting +10% Rear adjusters offer 1) Voltage difference level setting

2) Phase difference level setting 3) Relay time delay setting

Rear Input terminals require: 1) Voltage connection to bus bar

'BUS' 2) Voltage connection to generator

'GEN' Rear relay terminals: Single pole changover relay contacts

a.c 2S0V SA non inductive d.c 24 V 2A resistive

Front indications offer: 1) Two green triangular LED's for the relay state (Synchronised)

2) Green 'GEN' LED indicating the 'GEN' voltage level is OK

3) Red 'GEN' LED indicating the 'GEN ' voltage is under or over

4) Green 'BUS' LED indicating the 'BUS' voltage level is above SO% of nominal

S) Red 'BUS' LED indicating the 'SUS' voltage is below SO% of nominal

6) A Circle of 24 Red LEOs simulating a synchroscope

EMC compliance to: ENSOOS1-2, ENSOOS2-2 at 10V/M EMC Installation: See our technical sheet TS9/336

THE RANGE AND ORDERING INFORMATION

Model Description

077·14L Single Phase or 3 phase 3/4 wire LED Synchro check relay

077-14G as above 220/240V, (230V nominal) or 380/480V (430V nominal)

077·140 Single Phase or 3 phase 3/4 wire LED Synchro check relay with dead bus

077-14H as above 220/240V, (230V nominal) or 380/480V (430V nominal)

077-14A Single Phase or 3 phase 3/4 wire LED Synchroscope

the following:

1 T

Where T == The cycle time in seconds Example: If it takes 10 seconds for one cycle clockwise then the slip frequency is

1 = 0.1 HERTZ

10

Therefore if the 'BUS' frequency is SOHz the 'GEN' frequency is SO.1 Hz

The Necessity for Synchronising Several factors need to be considered to necessitate the synchronising and parallel running of generators.

1) When the generating capacity of a system has been exceeded

2) When enhanced reliability is being considered (Multiple V's Single Generating sets).

3) To operate generating sets efficiently by having the ability to add or remove sets as necessary.

4) When the economics of Co-generation and/or peak load shedding is being considered .

There are basically 2 types of synchronising

1) Manual 2) Semi-automatic

Mariual Synchronising Manual synchronising is widely used and a basic system incl udes synchronising lights , a synchroscope, some means of monitoring the system parameters and a breaker control switch . The operator controls the speed and voltage of the generator and the breaker switch. This method has the advantage of being simple and low cost, but it does require a knowledgable operator if damage to equipment is to be avoided. The Crompton model 077-14A can be used for this type of application.

Semi-automatic synchronising This method of synchronising is identical to that above with the addition of a synchro check relay. The relay provides a back-up to the operators decision to close the breaker since it will only energise when the voltage , phase difference and frequency are within the pre determined limits for a pre set time delay.

Th e synchro check relay is provided to back-up the operator's decision to close the generatoi' oreaker. The operator may even hold the manual breaker control switch closed until the synchro check relay permits the main current breaker close circuit to be energised. The Crompton model 077 -14L or 077 -14G can be used for this application and if connection to a 'Dead Bus ' is required then the Crompton model 077-140 or 077-14H is suitable.