Rockwell Automation 193-EDN E1Plus Overload Relays - DeviceNet Module - Manual (Page 13)

Publication 193-UM006A-EN-P – October 2005
Protection Functions 2-3
Jam Protection Motor current greater than the motor's nameplate rating can indicate a high
overload or stall condition, such as an overloaded conveyor or jammed gear.
These conditions can result in overheating of the motor, and equipment
damage. Rapid jam fault detection helps to minimize damage and loss of
production.
By continuously monitoring the motor current level signal as a percentage of
the E1 Plus Overload Relay's dial FLA setting, the DeviceNet module allows
jam trip and warning capability.
Jam Trip
The following parameters are available for configuring the DeviceNet
Module's jam trip performance:
• Parameter 18, Jam Inhibit Time, allows the installer to inhibit a jam trip
from occurring during the motor starting sequence. It is adjustable from
0…250 seconds.
• Parameter 19, Jam Trip Delay, allows the installer to define the time
period a jam condition must be present before a trip occurs. It is
adjustable from 0.5…25.0 seconds.
• Parameter 20, Jam Trip Level, allows the installer to define the current at
which the E1 Plus Overload Relay will trip on a jam. It is user-adjustable
from 150…600% of the FLA dial setting.
The DeviceNet Module will command the E1 Plus Overload Relay to trip if all
the following conditions are met:
• No trip currently exists
• Jam Protection is enabled
• Jam Inhibit Time has expired
• The motor current is greater than the Jam Trip Level for a time period
greater than the Jam Trip Delay
When the conditions for a jam trip are satisfied, the following will occur:
• Bit 2 in Parameter 3, Trip Status, will go to “1”
• Bit 0 in Parameter 10, Device Status, will go to “1”
IMPORTANT
%Therm Utilized will stabilize at a value of approximately
88% with the motor operating continuously at rated
current.