Frequency monitoring relay LINETRAXX® VMD461

phase sequencephase lossphase unbalance

Voltage monitoring up to 1200 V All functions are represented in ANSI codes 3-stage voltage and frequency monitoring with a corresponding response delay Can be used optionally for a wide variety of system configurations such as AC, 3AC, 3NAC and DC The multifunctional voltage monitoring relay VMD461 monitors frequencies, undervoltages and overvoltages in DC, AC and 3(N)AC systems. The phase voltages and/or line-to-line voltages are measured as r.m.s. value and are continuously shown on the device display. The measured value required to trigger the alarm relay is stored. The VMD461 features additional measuring functions for: ROCOF df/dt Vector shift monitoring Unbalance monitoring Phase sequence monitoring The corresponding ANSI codes for all available measuring functions are provided. Configurable delay times allow considering special installation-specific properties (e.g. device-specific start-up procedures). The VMD461 requires an external supply voltage. The optional use of a CD440 coupling device extends the voltage range that can be monitored to DC/3AC 1200 V or 1AC/3NAC 690 V. Features When combined with a CD440 coupling device, DC systems up to 1200 V, 1AC systems up to 690 V, 3AC systems up to 1200 V and 3NAC systems up to 690 V can be monitored All functions are represented in ANSI codes Monitoring of DC, 1AC, 3(N)AC systems DIN EN 60255-1:2010-9 Single-fault safety Unbalance, phase failure and phase sequence monitoring Monitoring of the connected switches and/or disconnectors (configurable: NC/NO/off) Islanding detection df/dt (ROCOF)