Electrical Relay

FEATURES

• Software based design

• Display of Power factor, Phase angle and frequency

• Dust proof enclosure

• Draw out type

APPLICATION

JRPv Oil is used to trip (dis-connect) capacitor bank from the line during lead power factor in the system.

PRINCIPLE OF OPERATION

The R-Phase line current input to relay is derived from the line CT. The R - B line voltage scaled to relay rated voltage using transformers. The relay measures the phase angle between R-Current and R-B voltage, the output contact operates when PF reaches lead condition after fixed operating time of 60s. The output contact release when PF reaches lag condition after fixed operating delay of 60s.

The aux supply required for the operation of relay is derived from the voltage input hence no need of dedicated power source.

The relay displays power factor, line frequency, phase angle between line current and voltage.

TECHNICAL DATA

FEATURES

• Solid state reliability

• Built in Trip test facility

• High sensitivity

• Low burden

APPLICATION

The relay is used to monitor the neutral earthing resistor. Transformer neutral is earthed through a resistance. This resistor is called as Neutral Earthing Resistor (NER). Neutral Earthing resistors are used to restrict the fault current through the transformer during earth fault conditions. The healthiness of NER is important as an open resistor would render earth leakage protection in operative and hazardous.

PRINCIPLE OF OPERATION

A very low DC current is passed through the NER and this is monitored in the relay. If there is an open cir­cuit in resistor or considerable change in the resistor value the same is detected in the monitoring circuit. After detecting the change, timer is shorted and output relay is deenergized at the end of internally set time delay ( 5 Sec ) The relay contact may be connected externally to Alarm/Trip circuit as required. Normally the output relay is kept energized. If there is a failure in Aux. Supply the output relay releases and extends the Alarm/Trip signal.

TECHNICAL DATA

APPLICATION

The relay is intended for use in the applications requiring.

1. Increased current-carrying or interrupting capability in a contact (low current contact energizes the coil to close the high current contact)

2. Circuit isolation.

3. Contact conversion ( for example, from a normally open to normally closed condition), or

4. Contact multiplication ( from one contact input to two contact output)

PRINCIPLE OF OPERATION

The applied input voltage creates the magnetic field on the armature and intend to operate or reset the relay.

TECHNICAL DATA

FEATURES

• Software based design

• Wide auxiliary supply

• Low burden

APPLICATION

The relay provides under voltage protection of Motors, Generators, Capacitor Banks etc.

PRINCIPLE OF OPERATION

JRV 014 provides under & over voltage protection for power systems. Relay operating time is determined by set definite time. The relay measures the voltage from input PT and if the voltage is below the set thresh­old, under voltage stage operates and voltage is above the set threshold, over voltage stage operates and it extends a trip signal after the operating time, which is determined by set definite time. The relay output con­tacts are self reset type. TEST button facilitates testing of relay contacts for trip and alarm circuits.

TECHNICAL DATA

FEATURES

• Two stage of frequency protection

• Digital display of line frequency

• Draw out case 144x144 mm

APPLICATION

The relay provides time graded over / under frequency protection. Used in industrial plants having captive power generators requiring under frequency protection.

PRINCIPLE OF OPERATION

The JRF 014 is microprocessor based frequency relay The relay can be configured for

TECHNICAL DATA

FEATURES

• Wide setting range

• Bright 7-Segment LED display

• Wide auxiliary supply

• Hand / Self reset type selection

APPLICATION

Digital time delay relay is used to provide delay in a circuit

PRINCIPLE OF OPERATION

The relay can be configured in one of three programmable modes designated as "0100", "0200", "0300". The difference in the functioning of DTDR when configured in the above mentioned modes is restricted to the manner in which its (NO) contacts of DTDR are reset.

DTDR, after sensing the operation (NO -> C) of a potential free contact (Timer Initiation Contact) connected to its terminals [6,7], starts decrementing its "relay operation timer" from an initial value. The ini­tial value of the "relay operation timer" corresponds to "time delay setting". After "relay operation timer" counts down to "0". DTDR operates its NO contacts.

DTDR reset operation in mode - "0100":

"0100" mode corresponds to "Hand Reset" mode. The NO contacts of the DTDR will remain in operated state until further human intervention. Following the operation (NO - > C) of DTDR contacts, DTDR can be reset by pressing "RESET" (RST) switch on the DTDR.

DTDR reset operation in mode - "0200":

"0200" mode corresponds to "TYPE-1 Self Reset" mode. Following the operation (NO -> C) of DTDR contacts, a "self reset timer" will start decrementing from a value equal to "Reset time delay". When this "self reset timer" reaches its terminal count ('0'), DTDR is reset.

DTDR reset operation in mode - "0300":

"0300" mode corresponds to "TYPE-2 Self Reset" mode. Following the operation (NO -> C) of DTDR contacts, DTDR transits to a wait state where it waits for the "Timer Initiation Contact" across [6,7] to change its state from "closed state TO Normally open state". When "Timer Initiation Contact" across [6,7] changes state from "closed state TO Normally open state", a "self reset timer" will start decrementing from a value equal to "Reset time delay". When this "self reset timer" reaches its terminal count ('0'), DTDR is reset.

TECHNICAL DATA

FEATURES

• Software based design

• Single phase & 3phase measurement

• Dust proof enclosure

APPLICATION

JRR 911 is used to trip (dis-connect) capacitor bank from the line during lead power factor in the system.

PRINCIPLE OF OPERATION

The R,Y and B-Phase line current input to relay is derived from the line CT. The R,Y and B line voltage scaled to relay rated voltage using transformers. The relay measures the phase angle between R,Y and B phase Current and R,Y and B phase voltage, the output contact operates when PF reaches lead condition after fixed operating time of 60s. The output contact release when PF reaches lag condition after fixed oper­ating delay delay of 60s.

The aux supply is required to power up the unit. The relay displays power factor, and lag indication.

TECHNICAL DATA