![background image](http://html1.mh-extra.com/html/eaton/66d2032g01/66d2032g01_manual_526694090.webp)
Page 90
I.L. 17562
PR 0.3 Effective 8/99
SECTION 9. APPLICATIONS AND SETTINGS
9.0 General —
This section is a supplement to Section 5, giving more engineering and
application guidance for particular functions and setpoints.
Use this data in conjunction with Section 5 and Table 4.3, to develop setpoints for the MP-3000,
as well as making appropriate wiring design. Note that particular setpoints are designated as
PnLm
, where
Pn
is the page number and
Lm
is the line number of the particular setpoint in
Table 4.3, and in the page-line-value scheme of accessing setpoints on the front panel of the
MP-3000.
9.1 Motor Protection —
The MP-3000 protects the motor, starter, and load in the following
ways:
•
Stator and rotor thermal protection by modeling of heating and cooling effects, including
heating by negative sequence currents.
•
Stator overtemperature protection by direct measurement (with optional URTD module).
•
Instantaneous overcurrent protection for faults.
•
Ground fault protection.
•
Phase reversal protection.
•
Phase unbalance protection.
•
Motor bearing and load bearing temperature protection (with optional URTD module).
•
Jam protection.
•
Underload protection.
•
Incomplete sequence protection (missing status feedback from load).
•
Trip-bypass output for failure of contactor to interrupt current after a trip.
9.1.1 Thermal Modeling and Overload Protection without RTDs —
Refer to Figure 9.1. The
motor overload protection function, called the I
2
T algorithm, calculates the rotor and stator
temperature based on effective heating current, integrated over time. Positive and negative
sequence current magnitudes are calculated in separate accurate algorithms. The effective
heating current is the sum of the positive and negative sequence currents, with a heavy
weighting factor on the negative sequence contribution. This models the disproportionate rotor
heating effect of the negative sequence current (see
Motor Thermal Protection Basics
,
Section 8). Certain harmonic currents such as the 5
th
and 11
th
also produce the same heating
effects as fundamental-frequency negative sequence current; this harmonic heating effect is also
measured and modeled.
The temperature rise caused by current flow is modeled with a thermal accumulator or bucket
whose size or capacity is derived from motor nameplate data entered as setpoints. The flow of
effective heating current into the bucket causes it to fill. Cooling is modeled by a gradual
emptying of the bucket. The setpoints which influence the heating and cooling models are:
•
Full-load amperes (FLA, P1L1)
•
Locked-rotor current (LRC, P2L2)
•
Maximum allowable stall or locked-rotor time (LRT, P1L3)
•
Ultimate trip current (UTC, P1L4), which is usually service factor times 100 percent.
The MP-3000 thermal bucket fills and proceeds towards a trip only when the effective heating
current is above the ultimate trip current setting, P1L4. The modeling is based on an ambient
temperature of 40 degrees C. A programmable I2T alarm I2TA, P4L2 informs the user when the
bucket reaches the user-set level between 60 percent and 100 percent full.
Without manual process load reduction, automatic process load shedding (see 9.1.5), or other
remedial action after an alarm, the relay eventually trips and displays the message LRC/I2T
Содержание 66D2032G01
Страница 18: ...Page 18 I L 17562 PR 0 3 Effective 8 99 Figure 4 1 MP 3000 Pushbuttons...
Страница 19: ...I L 17562 Page 19 PR 0 3 Effective 8 99 Figure 4 2 MP 3000 LED Indicators...
Страница 72: ...Page 72 I L 17562 PR 0 3 Effective 8 99 Figure 6 1 Panel Cutout Dimensions...
Страница 73: ...I L 17562 Page 73 PR 0 3 Effective 8 99 Figure 6 2 Faceplate Dimensions...
Страница 74: ...Page 74 I L 17562 PR 0 3 Effective 8 99 Figure 6 3 MP 3000 Case Depth Dimensions...
Страница 75: ...I L 17562 Page 75 PR 0 3 Effective 8 99 Figure 6 4 Universal RTD Module Mounting Dimensions...
Страница 76: ...Page 76 I L 17562 PR 0 3 Effective 8 99 Figure 6 5 Rear Panel Terminals...
Страница 77: ...I L 17562 Page 77 PR 0 3 Effective 8 99 Figure 6 6 Typical Ct Circuits and Motor Control Wiring...
Страница 78: ...Page 78 I L 17562 PR 0 3 Effective 8 99 Figure 6 7 Typical ac Supply and URTD Wiring...
Страница 79: ...I L 17562 Page 79 PR 0 3 Effective 8 99 Figure 6 8 Alternatives for Discrete Input Wiring...
Страница 80: ...Page 80 I L 17562 PR 0 3 Effective 8 99 Figure 6 9 RTD Wiring to URTD Module...
Страница 88: ...Page 88 I L 17562 PR 0 3 Effective 8 99 Figure 8 1 System Overview Figure 8 2 Torques from Sequence Currents...
Страница 100: ...Page 100 I L 17562 PR 0 3 Effective 8 99 Figure 9 1 Rotor Temperature Tracking...
Страница 101: ...I L 17562 Page 101 PR 0 3 Effective 8 99 Figure 9 2 Motor Protection Curve...
Страница 102: ...Page 102 I L 17562 PR 0 3 Effective 8 99 Figure 9 3 Underload Jam Protection Curve...
Страница 103: ...I L 17562 Page 103 PR 0 3 Effective 8 99 Figure 9 4 Motor Protection Curve Example without RTDs...
Страница 104: ...Page 104 I L 17562 PR 0 3 Effective 8 99 Figure 9 5 Motor Protection Curve Example with RTDs...
Страница 105: ...I L 17562 Page 105 PR 0 3 Effective 8 99 Figure 9 6 Motor Start and Run Cycles...
Страница 109: ...I L 17562 Page 109 PR 0 3 Effective 8 99 P5L8 40 Incomplete Sequence time 1 60s OFF 1 240s...