MINIMUM VOLTAGE RELAY MODEL PCEMROI CLW SPEC NO. CLW/ES/3/0060
Introduction:
All Power and Control Circuitry are sensitive to voltage variations. Severe low voltage may cause permanent damage to equipment, particularly employing electronic circuits. and a suitable protection mechanism is vital to protect these from extreme low input voltages. In electric locomotives the basic source of input is from the OH traction through pantograph and the most effective protection against low input voltage can be achieved by monitoring this voltage and activating a trip circuit for low-voltage-sensitive equipment by means of a Minimum Voltage Relay.
Basic Features:
A Minimum Voltage Relay should have the following features for effective and reliable operation. i) A signal input proportional to the traction voltage. ii) A dial-settable trip voltage to cover the entire desired range for trip voltage. iii) A dial-settable time delay for trip 'activation to avoid spurious trips owing to momentary dip in traction.
iv) A power source for the Relay that is separate and independent from the signal input for stable operation. v) Potential free contacts for extending to the no-volt release of sensitive equipment. vi) Low burden on both the signal and dc power sources.
GENERAL SPECIFICATIO S OF MINIMUM VOLTAGE RELAY
Signal Input: 240 V AC +/- 10% . 2 0 V AC 50-60 Hz
Trip Voltage Setting range : 136 V to 260 V AC 50-60 Hz
DC power source : 48 V DC +/- 10%
Rated burdens : AC 4 VA max ; DC 4 W max
Delay Time Setting Range : 0.2 sec to 20 sec
Open Potential Contact: AC 220 V, 5 A; DC 100 V 0.5 A
Ambient Temperature: -20°C to 70°C
Maximum Relative Humidity: 100%