QUICK REFERENCE GUIDE SYSTEM DATA
469 MOTOR MANAGEMENT RELAY – QUICK REFERENCE GUIDE 55
12.12 Thermal Model Setpoints
The S5 Thermal Model setpoints page contains setpoints for entering set-
tings related to protection of the motor during the starting process as well
as during normal operation.
As per the information provided above, the settings for the Thermal Model are entered
as follows in the
SELECT CURVE STYLE: “Standard”
OVERLOAD PICKUP: “1.25 x FLA”
ASSIGN TRIP RELAYS: “Trip”
UNBALANCE BIAS K FACTOR: “6”
COOL TIME CONSTANT RUNNING: “15 min.”
COOL TIME CONSTANT STOPPED: “30 min.”
HOT/COLD SAFE STALL RATIO: “0.89”
ENABLE RTD BIASING: “Yes”
RTD BIAS MINIMUM: “40°C” – ambient temperature
RTD BIAS CENTER POINT: “130°C” – center value
RTD BIAS MAXIMUM: “155°C” – maximum value
THERMAL CAPACITY ALARM: “Unlatched” – recommended for early warning to take
corrective actions and prevent the interruption of the process.
ASSIGN ALARM RELAYS: “Alarm” – the Alarm contact could be use for local indication,
or to send a local signal to reduce load, before a trip is issued.
THERMAL CAP. ALARM LEVEL: “80%”
THERMAL CAPACITY ALARM EVENT: “Yes” – captures event in the event report.
As well, select the overload curve for the Thermal model with the following setpoint in the
S5 THERMAL MODEL ZV OVERLOAD CURVE SETUP menu:
STANDARD OVERLOAD CURVE NUMBER: “7”
12.13 Current Elements Setpoints
The S6 Current Elements setpoints page contains setpoints for entering protection element
characteristics. In our example, these characteristics are specified under Motor Protection
heading.
From this data and the resulting calculations, program the S6 setpoints page as indicated.
When setting the relay for the first time, other setpoints not listed in this example should be
left disabled.
For the Short Circuit element, enter the following values in the
S6 CURRENT ELEMENTS Z
SHORT CIRCUIT TRIP
page. Press the MESSAGE T key after each setpoint is entered to
move to the next message.
SHORT CIRCUIT TRIP: “Latched”
SHORT CIRCUIT TRIP OVEREACH FILETER: “Off” - no filtering of DC component is
required
ASSIGN TRIP RELAYS: “Trip”
SHORT CIRCUIT TRIP PICKUP: “11.7”
INTENTIONAL S/C TRIP DELAY: “0 ms” - Instantaneous trip is required.
SHORT CIRCUIT TRIP BACKUP: “On” - if the main disconnect device does not respond to
the trip command, a second signal will be initiated via an auxiliary relay to generate a
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