Rockwell Automation 193-EC1_2_3_5, 193-ECPM,592-EC1_2_3_5 E3 and E3 Plus Solid-State Overload Relay User Manual - Manual (Page 72)

72 Rockwell Automation Publication 193-UM002I-EN-P - December 2011
Chapter 3 Protective Trip & Warning Functions
Frequency Protection
The E3 Plus model EC5 has the capability to protect against poor voltage quality
by offering frequency based protection. The user can prevent a contactor
fromenergizing if the voltage frequency is either too high or too low.
Under Frequency (UF) Trip
The E3 Overload Relay will trip with an under frequency indication if:
• no trip currently exists,
• Under Frequency protection is enabled,
• UF Inhibit Time has expired, and
• Volt Frequency is equal to or less than UF Trip Level for a time period.
greater than the programmed UF Trip Delay.
When the under frequency trip conditions are satisfied, the:
• TRIP/WARN LED will flash a red 1 long and 6 short blink pattern,
• bit 5 in V Trip Status, Parameter 160, will set to “1”,
• bit 0 of Device Status, Parameter 21, will set to “1”,
• Trip Relay contact will be open, and
• outputs will be placed in their Protection Fault state (if so programmed).
UF Inhibit Time, Parameter 233, allows the installer to inhibit an under
frequency trip from occurring during the motor starting sequence and is
adjustable from 0…250 seconds.
UF Trip Delay, Parameter 234, allows the installer to define the time period an
under frequency condition must be present before a trip occurs. It is adjustable
from 0.1…25.0 seconds.
UF Trip Level, Parameter 235, allows the installer to define the frequency in
which the E3 Plus Overload Relay will trip. It is adjustable from 0…250 Hz.
Under Frequency Warning
The E3 Overload Relay will immediately indicate an under frequency warning
condition if:
• no warning currently exists,
• UFWarning is enabled,
• UF Inhibit Time has expired, and
• Volt Frequency is equal to or less than the UF Warn Level.
When the under frequency warning conditions are satisfied, the:
• TRIP/WARN LED will flash an amber 1 long and 6 short blink pattern
• bit 5 in V Warning Status, Parameter 161, will set to “1”, and
• bit 1 of Device Status, Parameter 21, will set to “1”.