© 2010 SymCom, Inc. All Rights Reserved 9
Table 3: Trip Class Descriptions
Trip Class
Application Description
5
Small fractional horsepower motors where acceleration times are almost
instantaneous or where extremely quick trip times are required
10
(Fast Trip) Hermetic refrigerant motors, compressors, submersible
pumps and general-purpose motors that reach rated speed in less than
4 seconds
15
Specialized applications
20
(Standard Trip) Most NEMA-rated general-purpose motors will be
protected by this setting
30
(Slow Trip) Motors with long acceleration times (>10 seconds) or high
inertia loads
J Prefix
(Jam
Protection)
Programming any of the trip classes with the J prefix will enable jam
protection. This additional protection is enabled 1 minute after the motor
starts and provides a 2 second trip time for motors exceeding 400% of
the OC setting
Non-Standard
Trip Classes
Trip time in seconds when any phase current is 600% of OC. Time is
approximately 90% of the TC setting
1
10
100
1000
10000
0
100
200
300
400
500
600
700
800
900
1000
% of OC Setting
T
rip
Ti
me (Se
c
on
ds)
Class 30
Class 20
Class 15
Class 10
Class 5
Figure 3: Overload Trip Curves
