GE 339

6–48 339 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL
S3 PROTECTION CHAPTER 6: SETPOINTS
Figure 6-20: Thermal Protection logic diagram
OR
AND
AND AND
SETTING
Off = 0
Start Protection
THERMAL OVERLOAD CURVE
Standard curve
START PROTECTION
Curve Multiplier x 87.4
2
I - 1
eq
t(I )=
eq
t
LRcold
2
x I
LR
2
I
eq
t(I ) =
eq
SETTING
Thermal O/L Function
Enabled = 1
SETTINGS
BLOCK 1
Off = 0 BLOCK 2
AND
BLOCK 3 Off = 0 Off = 0
MOTOR STATUS
Starting
Running
OR
RUN
THERMAL MEMORY
TC Used =
t
I
TC Used RTD =
TC
MAX STATOR
TCU 15%≤
RESET TCU TO 0%
TCU > Thermal Alarm PKP
TCU =100%
I
eq
◊ O/L PKP
RUN
ACTUAL VALUES Hottest Stator RTD
I
avg
I
1
I
2
SETTING
Auto Reset TCU 15%≤
= Auto
= Manual
INPUTS
Remote Reset Input
SETTING
Lockout Reset
Off = 0
Emergency Restart Input Lockout Reset Input
Keypad Reset
AND
OROR
OR
OR
AND
OROR
OROR
AND
AND
NV
LATCH
S
R
AND
LOGIC OPERAND
Thermal Protection PKP
LOGIC OPERAND
Thermal OPProtection Any Trip OP
- LED: Lockout
SETTING
Thermal Alarm Func
Disabled = 0
AND
LOGIC OPERAND
Thermal LVL Alrm OP Any Alarm OP
Unbalance K Factor
Hot/Cold Ratio
Cool Time Stopped
RTD Bias - Minimum T
RTD Bias - Center T
RTD Bias - Maximum T
Thermal O/L PKP Thermal Alarm PKP
Cool Time Running
Curve Multiplier
Safe Stall Time - Cold Locked Rotor Current
SETTINGS
THERMAL PROTECTION
TARGET MESSAGE
Thermal Protection: State: Pickup
TARGET MESSAGE
Thermal : State: Operate
Protection
SETTING
Output Relay X
Do Not Operate, Operate
896LH3.cdr
Any Trip PKP
Disabled = 0
Lockout OP