Mains Loss Mode - Emerson 2202 Advanced User's Manual

Parameter
Menu 6 Introduction
x.00
Mode 3: Ramp to stop + timed DC injection braking
Pr 6.01 = 2
Phase 1
The drive will ramp down to zero frequency under the control of the selected ramp mode (Pr 2.04) in the time set by the deceleration rate.
Phase 2
Then DC current is injected into the motor at a level specified by Pr 6.06 and for a time specified by Pr 6.07.
Normally when this mode is used, phase 1 decelerates the motor to a stop and phase 2 locks the rotor shaft. This can be useful when trying to fully
stop an inertia load i.e. fan.
Mode 4: Injection braking stop with detection of zero speed
Pr 6.01 = 3
Phase 1
A low frequency current at 5Hz is injected into the motor at the level programmed by Pr 6.06, this will have the effect of slowing down the motor. When
the motor reaches 5Hz, the software goes into phase 2.
When the drive injects the low frequency current at 5Hz, it detects that regen current is flowing. When the motor reaches 5Hz, this regen current stops
and therefore the drive knows that the motor is at 5Hz.
Phase 2
DC current is injected into the motor at a level specified by Pr 6.06 and for a time specified by Pr 6.07.
The drive automatically senses low speed so therefore it adjusts the injection time to suit the application. If the injection current level is too small, the
drive will not sense low speed and it will sit at 5Hz (normally 50-60% is required in Pr 6.06).
Mode 5: Time DC injection braking stop
Pr 6.01 = 4
Phase 1
DC current is injected into the motor at a level specified by Pr 6.06 and for a time specified by Pr 6.07.
Phase 2
DC current is injected into the motor at a level specified by Pr 6.06 for 1 second.
The minimum total DC injection braking time is 1 second for phase 1 and 1 second for phase 2. Therefore the minimum DC injection braking time is 2
seconds.
Normally, the combination of the DC injection braking current level and injection braking time during phase 1 is used to stop the motor from rotating.
Then the 1 second DC injection braking in phase 2 is used to lock the motor shaft.
If the DC injection braking current level is set to a high level in Pr 6.06, the less time is required in Pr 6.07 to stop the motor. If the DC injection braking
current is set to a low level, the more time is required in Pr 6.07 to stop the motor.
6.02 Unused parameter
6.03

Mains loss mode

Bit SP
Coding
Range diS(0), StoP(1), rd.th(2)
Default diS(0)
Update rate 2ms
This parameter has 3 settings as follows:
Pr 6.03 Mnemonic
0 diS
1 StoP
2 rd.th
Mains Loss
There is no mains loss detection and the drive operates normally only as long as the DC bus voltage remains within specification (i.e. >Vuu). Once
the voltage falls below Vuu a UU trip occurs and this will reset itself if the voltage rises again above VuuRestart in the following table.
1 StoP
The action taken by the drive is the same as for ride through mode, except the ramp down rate is at least as fast as the deceleration ramp setting and
the drive will continue to decelerate to 0Hz even if the mains is re-applied.
Depending on whether the mains is re-applied during the ramp down phase will depend on what happens next:
• If the mains is not re-applied during the ramp down phase, the drive will trip on UU after it has reached 0Hz.
• If the mains is re-applied during the ramp down phase, when the drive reaches 0Hz and depending on the state of the control terminals, the drive
will either go into the 'rd' ready state or the drive will run back up to set speed.
Normally the controlling system will see that the mains has been lost and even though it has been re-applied, the controller will remove the run
terminal so that when it reaches 0Hz, it will go into the 'rd' state.
If normal or timed injection braking is selected, the drive will use ramp mode to stop on loss of the supply. If ramp stop followed by injection braking is
88
Parameter Keypad and
description format display
FI DE Txt VM DP ND
1
Function
Disabled
Stop
Ride through
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Serial CT Modbus PLC Ladder
communications RTU programming
RA NC NV PT US RW BU
1 1
Advanced parameter
CTSoft Menu 0
PS
1
Commander SK Advanced User Guide
Issue Number: 9
descriptions