Rtd Protection (38/49T) - GE 339 Instruction Manual

S3 PROTECTION

RTD protection (38/49T)

6–96
The 339 has two methods of supporting RTD inputs.
As an option, a CANBUS-based RMIO module can be installed on the 339, which can
monitor up to 12 RTDs. With the RMIO option, the RTD protection setpoints can be seen
only if the 339 has the RMIO module installed and validated. If, for some reason,
communications with the RMIO module are lost or interrupted, the 339 will issue an RMIO
MISMATCH self-test error indicating the failure. This feature is useful as it ensures that the
remote RTDs are being continuously monitored.
Alternatively, the INPUT/OUTPUT option 'R' can be selected from the Order Codes, an
option which provides 3 internal RTDs. The 339 does not support both Internal RTDs and
RMIO RTDs simultaneously.
The RTD type supported is 100 Ohm Platinum. Each of these may be configured to have a
trip temperature as well as an alarm temperature. The alarm temperature is normally set
slightly above the normal running temperature. The trip temperature is normally set at the
insulation rating. Trip Voting has been added for extra security in the event of RTD
malfunction. If enabled, a second RTD must also exceed the trip temperature of the RTD
being checked before a trip will be issued. If the RTD is chosen to vote with itself, the voting
feature is disabled.
Each RTD may also be configured as being of application type Stator, Bearing, Ambient or
Other. The table below - RTD Temperature vs Resistance - lists RTD resistance versus
temperature. RTDs configured as Stator type are also used by the thermal model for
determining the RTD Bias.
PATH:
SETPOINTS > S3 PROTECTION > RTD PROTECTION > RTD #1(12)
RTD #1 to 12 APPLICATION
Range: None, Stator, Bearing, Ambient, Other
Default: None
Sets the application type.
RTD #1 to 12 NAME
Range: 1 to 18 characters
Default: RTD 1(12)
Sets the RTD programmable name.
RTD #1 to 12 ALARM
Range: Disabled, Enabled
Default: Disabled
This setting enables the RTD #1 to 12 Alarm functionality.
RTD #1 to 12 ALARM TEMP
o o
Range: 1 C to 250 C in steps of 1
o
Default: 130 C
Sets the Alarm temperature.
RTD #1 to 12 ALARM PKP DELAY
Range: 0.00 to 600.00 s in steps of 0.01 s
Default: 2.00 s
Sets the Alarm pickup delay time.
RTD #1 to 12 ALARM DPO DELAY
Range: 0.00 to 600.00 s in steps of 0.01 s
Default: 2.00 s
Sets the Alarm dropout delay time.
o
C
339 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: SETPOINTS