Rockwell Automation Publication 193-UM015E-EN-P - October 2015 367
Protective Trip and Warning Functions Chapter 6
Undervoltage Protection
Electric motors consume more electric current when the voltage supplied to the
motor is lower than the motor nameplate rating. This can damage to an electric
motor over an extended period of time. The E300 relay can monitor for this
condition with its Under Voltage Trip and Warning function to detect for low
voltage levels to minimize motor damage and loss of production.
Under Voltage Inhibit Time
Under Voltage Inhibit Time (Parameter 355) allows you to inhibit an under
voltage trip and warning from occurring during the motor starting sequence. It is
adjustable from 0…250 seconds.
Table 291 - Under Voltage Inhibit Time (Parameter 355)
Under Voltage Trip
The E300 relay trips with an undervoltage indication if:
• No trip currently exists
• Under Voltage Trip is enabled
• Voltage is present
• Under Voltage Inhibit Time has expired
• The minimum phase voltage is less than the Under Voltage Trip Level for a
t
ime
period greater than the Under Voltage Trip Delay.
If the E300 relay trips on an under voltage, the:
• TRIP/WARN LED status indicator flashes a red 1-long / 1-short blink
patter
n
• Bit 0 in Voltage Trip Status (Parameter 5) sets to 1
• Bit 0 in Device Status 0 (Parameter 20) sets to 1
• Any relay outputs configured as a Trip Relay open
• Any relay outputs configured as a Control Relay open
• Any relay outputs configured as a Trip Alarm close
• Any relay outputs configured as a Normal Relay are placed in their
P
r
ote
ction Fault state (if so programmed)
Default Value 10
Minimum Value 0
Maximum Value 250
Parameter Type USINT
Size (Bytes) 1
Scaling Factor 1
Units Seconds
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