The following functions are available
- Robust static design
- Auxiliary DC supply monitor
- Fast operating time (15 ms)
- Simple pickup voltage setting by resistors through shorting links
- LED alarm indicator
- Option “Bus-wire alarm” (supervision)
- Option “Blocked external” by binary input
- Wide-range auxiliary power supply
- Latched trip contact (lockout function). Reset by binary input.
- Adjustable max. voltage pickup setting by a jumper between 60 V or 240 V Application :- The relatively simple electronic design of the 7VH60 provides a robust and reliable relay suitable for all high-impedance circulating-current protection applications. The use of a static measuring circuit ensures constant and fast tripping times. Optionally, the relay is available with a bus-wire supervision feature. If during operation a differential current above the supervision pickup threshold but below the relay pickup voltage is detected, the differential protection is blocked after a selectable span of time. The bus-wire supervision pickup threshold is settable by means of jumpers. Likewise, the delay time for pickup of the supervision can be set by jumpers within a range between 1 s and 10 s
This High-Impedance Differential Protection Relay Block is easily insert in your schematic diagram and connect as you like way.
The 7VH60 relay is a single-pole sensitive current relay. The AC input impedance of the relay is adjusted by means of a series of high-wattage resistors. The relay setting in voltage pickup value is effected by removing shorting links from the rear terminals. When a shorting link is screwed between the terminals, the resistor is shorted out and when the shorting link is removed, the resistor is in circuit. Each resistor has a voltage value which is the pickup current of 20 mA multiplied by the resistors ohmic value. The relay voltage setting is determined by adding up the voltage drops at the resistors which are not shorted out by shorting links (series resistors in circuit) plus a minimum base voltage setting. A maximum setting of 60 V (shorting links of the left side) or 240 V (shorting links on the right side) is possible. On delivery, the shorting links are pre-installed in either right-side or left-side position, depending on the ordered version. LSP2382-afp.tif The input from the CT varistor is connected to terminals 1 and 2. The sensitive relay input transformer galvanically isolates the relay static measuring circuit from the main current transformers. The AC measured current is filtered and rectified to a proportional DC voltage. This voltage is monitored by a Schmidt trigger circuit. If the set DC voltage, equivalent to the relay rated operating current of 20 mA is exceeded, then the trigger operates to energize the trip contact as well as the operation LED. The auxiliary DC supply is connected to terminals 30 and 31. An auxiliary DC supply monitoring circuit consisting of a green LED and an NO/NC relay contact is provided to indicate the status of the DC supply.
The SIPROTEC 7VH60 high-impedance differential relay contains all the components needed for:
1. Acquisition and evaluation of measured values
2. Operation and LED display
3. Output of trip commands and signals
4. Input and evaluation of binary signals
5. Auxiliary voltage supply.
All protection functions including the DC/DC converter are accommodated on a printed circuit board of double-height Eurocard format. An earthing screw is provided at the housing nto which earthing strips can be connected in order to ensure low-impedance earthing. The heavy-duty current plug connector provides automatic shorting of the CT circuits whenever the module is withdrawn. There are two unit versions available. The flush-mounting and cubicle-mounting versions have their terminals accessible from the rear. The surface-mounting version has the terminals accessible from the front.
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