Phase Overvoltage (59P) - GE 339 Instruction Manual

CHAPTER 6: SETPOINTS

Phase overvoltage (59P)

NOTE:
NOTE
339 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL
An overvoltage on a running motor with a constant load results in decreased current.
However, iron and copper losses increase, causing an increase in motor temperature. The
current overload element will not pickup this condition and provide adequate protection.
Therefore, the overvoltage element may be useful for protecting the motor in the event of
a sustained overvoltage condition. The 339 provides 2 Phase Overvoltage elements. Each
element can be set to either cause a trip or generate an alarm when the input voltage
exceeds the pickup level for a specified time delay. If it is desirable to have an alarm before
a trip occurs, the user can set the function of one Phase Overvoltage element to ALARM,
and the function of the other element to TRIP. For wye-connected VT, the input voltage is
phase-to-ground voltage; for delta-connected VT, the input voltage is phase-to-phase
voltage. The Phase Overvoltage operation can be set for phase combinations including
"Any One", "Any Two" and "All Three". If overvoltage tripping is enabled, and the setting PH
OV PHASES is set for "Any One", a trip will occur once the magnitude of any input voltage
(wye-connected VT: phase-to-ground voltage; delta-connected VT: phase-to-phase
voltage) exceeds the pickup level for a period of time specified by the time delay. On the
other hand, if overvoltage trip is enabled, and the setting PH OV PHASES is set for "All
Three", a trip will occur only when the magnitudes of all three input voltages exceed the
pickup level for a period of time specified by the time delay.
The following path is available using the keypad. For instructions on how to use the
keypad, please refer to Chapter 3 - Working with the Keypad.
Blocking the voltage based elements via the Block setting of the desired elements is highly
recommended if "VFD Not Bypassed" is asserted.
PATH:
SETPOINTS > S3 PROTECTION > PHASE OV1(2)
PH OV FUNCTION
Range: Disabled, Alarm, Latched Alarm, Trip
Default: Disabled
For details see Common
PH OV PKP
Range: 0.00 to 1.25 x VT in steps of 0.01
Default: 1.25 x VT
This setting defines the Phase OV pickup level.
PH OV DELAY
Range: 0.00 to 600.00 sec in steps of 0.01
Default: 2.0 s
This setting specifies the time delay before OV operation.
PH OV PHASES
Range: Any One, Any Two, All Three
Default: Any One
This setting selects the combination of overvoltage conditions with respect to the
number of phase voltages over the overvoltage pickup setting.
OUTPUT RELAY X
For details see Common
BLOCK 1/2/3
For details see Common
setpoints.
setpoints.
setpoints.
S3 PROTECTION
6–79