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Earth Monitoring Relays (EMR)
Sensitivity to supply Voltage fluctuations like Spikes etc might damage
the hardware or corrupt the data on software and is a common problem
with almost all of the electrical equipment.
Computers are frequently installed on dedicated clean circuits for a
clean supply. Further, these also have inbuilt suppression and
filtering circuitry which may leak the unwanted components of electric
supply to earth. Earthing is required to carry a significant amount of
continuous leakage current in case when large numbers of computers are
connected on same circuit. Isolation of any section will rise to
potentially lethal voltage if there is any breakage in the earth
connection which may also result in the failures of the computers due
to voltage spikes. As recommended in IS 3043 (Section 39.2.4.2),
providing a protective device for monitoring the continuity of the
protective earth connection is mandatory. This is also required for
providing the means of automatic disconnection in case of failure or at
least give an audio alarm to user.
Our Earth Monitoring Relay is widely in choice as it senses the rise in
the voltage between the earth and neutral conductors and also detects
the integrity of the earthing connection. These are advised to be
installed at UPS supply pints and possess following features:
Available in door mounting (96 x96mm) channel mounting models
Smart design that can fit on any mounting channel
Choice of screw less terminals
Total wireless interiors
± 2% Accuracy
Test & Auto/Manual Reset facility
Designed for high reliability, as relay energizes only under fault conditions
Technical Data
Supply Voltage (control supply) : 110V /220V / 380V / 440V AC, 50Hz or 12V DC / 24V DC
Permissible Supply Variation : ± 25%
Output Contacts: Two changeover contacts / One change over with Buzzer
Switching duty: 6A resistive at 24V DC or
240V AC
Relay Status: De-energised in normal conditions
Set Point (Range): 1- 10 V AC
Time delay (optional): 0.1-10 sec.
Settable
Mode of operation: Over voltage
Reset: Automatic/Manual.
Setting Accuracy: ± 5% of full scale
Mounting: Any standard mounting channel
Dimension: 77mm (W) X 90mm (H) X 110mm (D). For VR96-1 = 96mm (W) x 96mm (H) x 70mm (D)
Optional time delay for relay output
Operation
This relay has an easy mode of operation as it senses voltage between
earth & neutral terminal on load side continuously. Voltage
increases once the earth gets disconnected and the relay give output
for tripping or audio alarm when voltage rises above the limit set on
the dial.
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