VME420

Bender Incorporated 700 Fox Chase, Coatesville PA 19320 Tel.: (800) 356-4266 Fax: (610) 383-7100 VME420 Multi-functional monitoring relays for overvoltage, undervoltage and frequency monitoring in AC/DC systems with external supply voltage Product description The voltage relays of the VME420 series are designed to monitor the frequency, undervoltage, overvoltage and the voltage between two threshold values (window discriminator function) in AC and DC systems. The voltages are measured as r.m.s. values. The currently measured value is continuously shown on the LC display. The measured value leading to the activation of the alarm relays will be stored. Due to adjustable response times, installationspecific characteristics, such as device-specific start-up procedures, short-time voltage fluctuations, etc. can be considered . Device version VME420 requires an external supply voltage. Typical applications Single VME420 3.1 -phase voltage and frequency monitoring of machines and electrical installations Earth fault monitoring in medium-voltage systems via voltage transformers Monitoring of battery systems Switching on and switching off at a certain voltage level Function Once the supply voltage is applied, the start-up delay “t” is activated. Measured voltage and frequency values changing during this time do not influenc e the switching state of the alarm relays. The devices provide two separately adjustable measuring channels (overvoltage/undervoltage). When t...