Eaton MP-4000, Инструкция по установке, эксплуатации и техническому обслуживанию

Страница: 81 / 112

www.eaton.com Page 9-5
MP-4000 IB02602002E
TRN T/C - Transition on time and current. Both must occur, and the
current must drop below the setting before the time delay expires. If
the timer expires before the current falls below the set transition level,
trip the motor.
If there is no transition trip, and the MP-4000 relay declares a suc
-
cessful transition, the display and data communications messages
indicate RUN. If P10L1 is set to TRN ON, the AUX 2 output relay
operates its contact when the transition is declared. This contact con-
trols a reduced-voltage starter, switching to full running voltage.
Even if the transition control output contact is not used, set the transi
-
tion function to provide clear indications of the actual state of the
motor (START versus RUN) on the front panel display and via data
communications. A good way to do this is to use the settings of P5L7
= TRN T+C and P5L5 = 130% of FLA. Modify the latter, if needed,
to lie at a transition value between the starting current and post-start
maximum load current. Set the transition timer well beyond the nor
-
mal start time to avoid a transition trip.
9.2.2 Start Delays
When the MP-4000 declares a START, all start timers of enabled
functions begin to time. Each of these timers blocks the respective
function until the set delay expires. These start timers are affected
by transitions - they run for the set time, which may be less than or
greater than the time of transition. These timers include:
Ground fault start delay (GFSD, P3L2);
Instantaneous over current start delay (IOCSD, P3L5);
Jam trip and alarm start delay (JMSD, P3L7);
Underload trip and alarm start delay (ULSD, P3L10);
Unbalance trip and alarm start delay (UBSD, P3L13);
Voltage unbalance start delay (VUSD, P15L3);
Under frequency start delay (UFSD, P16L2);
Over frequency start delay (OFSD, P17L2);
Under voltage start delay (UVSD, P19L7);
Under power start delay (UTSD, P20L5); and
Power factor start delay (PFTS, P21L5).
Also, at the time of the start, the counters and timers for the jogging
controls are updated. These include starts allowed per time (ST/T and
T/ST, P5L1 and P5L2), time between starts (TBS, P5L3), and number
of cold starts allowed (NOCS, P5L4). If a jogging limit is reached, only
a STEX alarm occurs, but if the limit still applies when the motor next
stops, the motor is tripped and blocked at that time.
9.2.3 Run Cycle
When the transition occurs, the MP-4000 declares the run state for
the motor. A RUN message is displayed and communicated to the
PowerNet host.
9.2.4 Run Delays
Note that run delays on trip and alarm functions don’t have any
particular relationship to the transition to the RUN state of the relay.
Run delays are pickup delays on active functions, which are able to
measure as soon as the respective start delay has expired. Refer to
Subsection 9.2.2 for start delay details. The primary function of run or
pickup delays is to prevent nuisance tripping. These delays are:
Ground fault run delay (GFRD, P3L3);
Jam trip run delay (JMTR, P3L8);
Underload run delay (ULTR, P3L11);
Phase unbalance alarm run delay (UBTR, P3L14);
Jam alarm run delay (JMAR, P4L4);
Underload alarm run delay (ULAR, P4L6);
Unbalance alarm run delay (UBAR, P4L8);
Load shed delay for pickup and dropout (LSDL, P9L3);
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Voltage unbalance run delay (VUTR, P15L4);
Under frequency run delay (UFTR, P16L3);
Over frequency run delay (OFTR, P17L3);
Over voltage run delay (OVTR, P18L13);
Under voltage run delay (UVTR, P19L3);
Under power run delay (UTTR, P20L2); and
Power factor run delay (PFTR, P21L6).
9.2.5 Stop Cycle
The run cycle continues until the motor current level falls below the
Stop Current Threshold (STOP XX, P1L9) setting current on all three
phases. Then, a stop is declared. Jogging limits, as listed in Sub
-
section 9.2.2, and the anti-backspin time delay (ABKS, P5L12) are
checked. If required, the MP-4000 trips with the appropriate display
message(s). Remaining jogging block times are displayed and
counted down, indicating how long to wait. If there are no such starting
block conditions in effect, the MP-4000 closes (or never opens) the trip
contact and displays READY - 3.
9.2.6 Trips and Trip Bypass
If any of the motor protective functions operate while the motor starts
or runs, the MP-4000 opens its trip contact and displays the cause(s)
of the trip. It may also open its trip contact after a stop is recognized if
any jogging function time limit is blocking the next start. In either case,
the MP-4000 expects that the contactor has opened in response and
that no current flows.
If the MP-4000 senses noticeable current for more than about a
second whenever it is tripped, it declares a trip bypass and displays
a message. This means that the relay blocking of the contactor has
been circumvented by the User to start the motor. If the current fails to
stop when the MP-4000 trips a running motor, it may be because of a
User trip bypass, or a stuck contactor.
Consider the possibility of backup protection for a contactor opening
failure. Configure the AUX1 or AUX2 output relay to pick up for a trip
bypass. Connect the contact to trip an upstream breaker. This pro
-
tects the motor from damage in case of a stuck contactor (at the cost
of interrupting other loads connected to the same breaker).
9.2.7 armed/Disarmed Mode
If the MP-4000 is DISARMED (P12L18), trip messages are displayed,
but the trip relay is not operated. This is useful in a critical process, if it
is imperative to keep the motor running while settings are changed or
the relay is replaced. Commission the new relay or settings in the DIS-
ARMED state. Make sure the relay is also set for RUN PGM (P12L6)
before commissioning. Watch for any trip messages and observe the
contents of the thermal bucket for a while. When it is apparent that the
relay behavior is secure and stable, change P12L18 to ARMED.
9.3 aC line Interruptions
The MP-4000 has an exceptional ability to ride through voltage sags
and interruptions, even longer than a delayed-dropout contactor it
controls. With this capability, most Users can avoid the addition of a dc
battery supply or an uninterruptible power supply (UPS).
The MP-4000 relay operates continuously for ac supply voltages down
to 55% of rated value (66 Vac for a 120 Vac supply system; 132 Vac for
a 240 Vac supply).
•
•
•
•
•
•
•