P YOG EARTH

LEAKAGE /

RELAYS I

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SOLID STATE ,

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PRAYOG make Solid State Earth Leakage (SSEL) Relays are fast acting, alternating current type. They are sensitive, reliable and robust; hence they find a variety of applications such as:

1 .Earth-fault withlwithout core-balance Current Transformer

2.Mertz-price protection. 3.Split conductor feeder protection.

The relay illustrated is ideal for use in a scheme for sensitive earth-fault protection. On three phase systems with three current transformers it is possible to connect the secondaries of the current transformers in such a way as to permit the earth fault current to flow through the relay. The use of one core balance current transformer with the associated cable provides an effective and sensitive method of earth-fault protection. SSEL Relay in combination with our core- balance Current transformer is thus ideally suited for application in mines, collieries, motor control panels etc.

DESCRIPTION:

The SSEL Relay is a solid state unit with CBCT (Core balance current Transformer) to sense the leakage current. The CBCT is mounted externally and the load carrying cables are passed through the CBCT. Thq incoming and outgoing currev are equal and opposite in direction in a leakbge free system, which technically means that the vector sum of current is zero.

In case of leakage either due to insulation failire or direct phase to ground fault, th6 vector sum of current is not z q o and therefore generates a resultant magnetic-

flux in the core of the CBCT. This flux induces a voltage in the secondary of the CBCT, which is fed to the relay. This signal is compared with internal references and the instant the Pre-set level of current is crossed, the relay is activated.

The pre-set value can be adjusted by the "calibrated dial" potentiometer.

Unequallunbalance loading'on phases, dose not affect the vector sum and such there is no difficulty in the use of the relay on-dectrical distribution systems with Unequal/ unbalance loading. The Relay activates only under leakage / earth fault conditions.

Every operation of the relay is indicated by an LED indicator. Change over contacts are provided for relaying signal to control circuit. It is customary to insert the contacts in the shunt-trip / no volt coil of the circuit breaker controlling the feeder which is to be protected.

The RESET push button is provided for indicating the occurrence of a fault and when pressed extinguishes the LED indicator, normalising the relay contact.. If specifically required, relays can be provided without this feature.

Test facility is provided to ensure proper functioning of relay. On pressing "TEST push button", a known current is passed through the test winding. The current energises the relay circuit independent of the set trip current. This checks the functioning of the relay including the CBCT. 't

4 All relays are tested rigorously at the works to ensure satisfactory operation and servi ce. Where core-balance type of protection is envisaged the relay is normally supplied

calibrated with its own core-balance current transformer bearing the same Serial No.lt is important that the relay be used with its own core-balance current transformer.

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STALLATION AND OPERATION: E. 1. Examine the SSEL relay with

corresponding CBCT for physical damage.

2. The CBCT should be installed on the cable of the feeder to be protected by threading the cable (all phases and neutral only) through the opening of the CBCT The CBCT should be suitably supported and leads marked Rl ' and R2' should be connected to the relay terminals marked 'R1' and 'R2'. Leads 'TI ' and 'T2' are for connection to the test circuit terminals 'TI ' and 'T2' on relay.

EH WIRElSHEATHINGlARMORINGl MUST NOT BE PASSED THROUGH CBCT.(see SSELR & CBCT connection diagram for earth connection) - -

3. Ensure that SSEL relay is connected to proper supply voltage as indicated in your order.

4. On the removal of top transparent cover, Reset and Test push-bottons and setting dial are accessible. Primary leakage current trip Settings are marked in terms of Primary leakage current in suitable range to cover total range such as (1 to 4 Amps., 2 to 8 Amps., 0.1 to 0.4 Amps., 0.05 to 0.2 Amps.)

5. A FAIL SAFE feature is optionally available at no extra cost. In SSEL relay, with this feature when energised with Auxiliary supply, change over of Auxiliary contacts take place. In the event of failure of Auxiliary supply the relays trips immediately, normalising the auxiliary contacts, thus providing complete safety.

6. A model of relay is also available in 96 x 96 mm size for flush mounting on specific request. [ Panel cut-out size(91 x 91) +0.1- O.Omm].

The SSEL relay does not need any maintenance internally as it employs solid state circuitry. Once in a month, check the state of internal wiring, tighten all external connections, if loose. Press 'TEST' push button to check performance of SSELR. On pressing the 'TEST' button, the relay should trip and in turn should trip the main breaker( i.e. MCCBIOCBI Starter in use.).

It is not necessary normally to stock any spares, but if need arises, spares will be supplied on a priority basis to users.

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GUARANTEE:

All Sets are tested carefully before despatch and are guaranteed against defective material and/or workmanship for a period of 12 months from the date of despatch.

ER 'PRAYOG' PRODUCTS.

A.C, High Voltage Tests Sets (Dry type) from 0-5 kV to 0-75 kV Oil Testing sets.- 0-60 kV & 0-1 00 kV Manual, Motorised & with Stirrer. Current Transformer:- Indoor and Outdoor. Voltage Transformers:- Indoor and Outdoor. Special application Transformers.

NOTE: Due to constant improvements in design, right is reserved to supply product which may differ slightly from those illustrated and described in this pamphlet.

S.No. Description Specification 1. Auxiliary supply : 110or240or

440 VAC,any one ( ~ 1 5 % )

2. Auxiliary Contact . : 3Amps.AC rating : Inductive

3. Operating time : 30 ms 4. VA Burden : 2VA 5. Withstand voltage Test : 2.5 KV 6. Max. Operating Temp : 60C. 7. Relative Humidity @40C : 95% 8. Dimensions

a) Flushtype-151 x 126xl55mm. [ Panel cut - out size (128 x 113) 4-0.1 - Ornm ] b) Projection type - 120 x 200 x 100 mm.

-p?---T-> - RMIJON REQUIRED FOR ORDERING

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1. Earth Leakage Current Setting : A to A 2. Mounting Type a) Flush or b) Projection 3. Supply Voltage 1 10 or 240 or 440 AC or

any other ( any one ). 4. Inner dia of CBCT for cable entry

CBCT Type : a) Tape insulated mm dia. b) Cast Resin mm dia.

5. Reset facility : a) Hand reset or b) Self reset.

6. ~(Dciliar~ change over Contacts : a) One or b) Two

7. Fail Safe feature - Required / Not required

INPUT CBCT WITH TEST WDG.flI -T1/ L

- E I4 R Y B I I I I I /SIG!