The DC voltage monitoring relay type E27D is a digital or microcontroller base relay, commonly used for monitoring battery voltage conditions, but can be used in any applications which dc voltage level is critical too. The relay is provided with 1 volt step adjustable pickup and dropout voltage with time delay 0 ~ 60 seconds set point. By the way, the relay can be adjusted voltage between 75% – 125% of Un moreover, it has watchdog function to monitor the healthy of itself.
When power is applied to the relay the green LED (Healthy) will start flashing (watchdog function is working), simultaneously the orange LED (P/U) will light up to show that the DC voltage is on normal condition or the input voltage exceeds the pickup setting (P/U). When the monitor voltage falls below the dropout setting (D/O), the time delay is initiated and the red LED (27 – Under voltage LED display) start flashing until time delay reached the set point value. (The response time delay of the relay can be adjusted between 0 ~ 60 seconds) Then the LED stop flashing but steady on, simultaneously with relay energizes or switches to its operating position. The relay will reset once the monitored voltage rises above the pickup set point, the time delay is initiated and the orange LED (P/U) start flashing until time delay reached the set point value. Then the LED stop flashing but steady on, simultaneously with relay reset to normal.
In case of voltage increased to the over voltage set point the orange LED (over) will flashing to show that voltage had reached the set point value until the setup time delay is time out than the orange LED (over) stop flashing but study on and over voltage contact output close or become NC status.