GE 339

6–138 339 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL
S4 CONTROLS CHAPTER 6: SETPOINTS
Figure 6-56: Start Inhibit, Starts per Hour, Time Between Starts, and Restart Inhibit
logic diagram
STARTS/HOUR COUNTER
SETTING
t = Time Between Starts
do
0
t
do
LOGIC OPERAND
TIME-BTWN-STARTS INHIBIT
ACTUAL VALUE
TIME-BTWN-STARTS INHIBIT
setting = OFF
AND
I
avg
> Current Cutoff Level
I
avg
SETTING
t = Restart Inhibit
do
0
t
do
LOGIC OPERAND
RESTART INHIBIT
ACTUAL VALUE
RESTART INHIBIT
setting = OFF
AND
Starts/Hour Limit
ACTUAL VALUE
STARTS/HR INHIBIT
Counter setting≥
AND
setting = OFF
SETTING
LOGIC OPERAND
STARTS/HR INHIBIT
MOTOR STATUS
Running
Starting
Clk
In
Thermal Capacity Used
-
+
Clk
In
Clk
In
Clk
In
Clk
In
Clk
In
Select
Largest
Value
Edge Triggered
Sample & Holds
(Non-Volatile)
SETTING
m = Thermal Inhibit
setting = OFF
setting = 0%
TC
in
LOGIC OPERAND
THERMAL INHIBIT
ACTUAL VALUE
ACTUAL VALUE
AND
Tc + m/100 x Tc
in in
TC
learned
TCU
85%
Learned TCU
*saturates at 100%
COMMAND
Clear Learned TCU
Preset PresetPresetPresetPreset
Presets latches to 85%
THERMAL INHIBIT
896834.cdr
TC > 100% - TCU
learned
LOGIC OPERAND
THERMAL INHIBIT
STARTS/HR INHIBIT
TIME-BTWN-STARTS INHIBIT
RESTART INHIBIT
FUSE FAIL INHIBIT
PH REVERSAL INHIBIT
OR
LED: Start Inhibit
Operate Output Relay 3 (Start Inhibit)