GE 239 Instruction Manual page 50

4 PROGRAMMING
above. In between these two extremes there is a linear relationship; the 239 thermal model cov-
ers the entire range of motor temperatures: cold—cool—warm—hot. The steady state value of
thermal capacity used for any phase current level can be calculated as:
Thermal Capacity Used
For example, if LRT Hot = 7.0 s, LRT Cold = 10.0 s, FLC = 100 A, and the actual motor current is
80 A, then the steady state thermal capacity value will be:
Thermal Capacity Used
4
• DISABLE STARTS: In some applications start protection may not be required. Therefore, by set-
ting this setpoint to <(6 , the start protection on the 239 can be defeated. If the setpoint is set to
<(6 , the 239 will go directly into run condition and overload curves will be employed to protect the
connected load.
This setpoint can also be used in conjunction with a switch input. If the ',6$%/( 67$576 setpoint is
programmed to <(6 and 237,21 6:,7&+  )81&7,21 setpoint described on page 4–33 is assigned
to ',6$%/( 67$576 , the 239 start protection will be defeated if the respective switch input is closed.
The ',6$%/( 67$576 setpoint must be programmed to <(6 for the feature to work via the switch
inputs.
4-12
Courtesy of NationalSwitchgear.com
Actual Current
× (
------------------------------------- -
100% HOT/COLD CURVE RATIO
=
FLC Setpoint
Actual Current
× (
------------------------------------- -
= 100% HOT/COLD CURVE RATIO
FLC Setpoint
 
80 7.0
×
--------- - 100% ---------- -
= –
 
100 10.0
20%
=
239 Motor Protection Relay
4 PROGRAMMING
–
–
 
×
100%
 
)
)
GE Multilin