Operating instructions

6 Commissioning Issue 10/06
MICROMASTER 430
54 Operating Instructions (Compact)
Mains
Inverter Motor Starters
Pressure Sensor
To Inverter PID Input
Inverter Motor Starters
Pressure Sensor
To Inverter PID Input
Mains
MV M1 M2 M3
MV - Variable speed motor M2 - Motor switched with relay 2
M1 -
Motor switched with relay 1 M3 - Motor switched with relay 3
By default the motor starters are controlled from relay outputs (DOUT1,2,3).
Staging
When the inverter is running at maximum frequency (P1082), and the PID feedback
indicates that a higher frequency is required, the inverter switches on (stages) one of the
relay controlled motors M1 to M3.
The drive inverter simultaneously ramps-down to the
staging frequency (P2378); in so doing, an attempt is made to keep the controlled variable
as constant as possible. Therefore, during the staging process, PID control is suspended
(see P2378 and diagram below).
P2371 = 0
1
2
3
4
5
6
7
8
Staging of external motors (M1, M2, M3)
--------
-M1M1M1M1M1M1M1
- M1 M1+M2 M1+M2 M1+M2 M1+M2 M1+M2 M1+M2
- M1 M2 M1+M2 M1+M2 M1+M2 M1+M2 M1+M2
- M1 M1+M2 M1+M2+M3 M1+M2+M3 M1+M2+M3 M1+M2+M3 M1+M2+M3
- M1 M3 M1+M3 M1+M2+M3 M1+M2+M3 M1+M2+M3 M1+M2+M3
- M1 M2 M1+M2 M2+M3 M1+M2+M3 M1+M2+M3 M1+M2+M3
- M1 M1+M2 M3 M1+M3 M1+M2+M3 M1+M2+M3 M1+M2+M3
- M1 M2 M3 M1+M3 M2+M3 M1+M2+M3 M1+M2+M3
t
1. 2. 3. 4. 5. 6. 7.
Switch-on
De-staging
When the inverter is running at minimum frequency (P1080), and the PID feedback
indicates that a lower frequency is required, the inverter switches off (de-stages) one of the
relay controlled motors M1 to M3.
In this particular case, the drive inverter ramps down from
the minimum frequency to the staging frequency (P2378) outside the PID closed-loop
control (see P2378 and diagram below).
P2371 = 0
1
2
3
4
5
6
7
8
--------
M1-------
M1+M2 M1 - - - - - -
M1+M2 M2 M1 - - - - -
M1+M2+M3 M2+M1 M1 - - - - -
M1+M2+M3 M3+M1 M3 M1 - - - -
M1+M2+M3 M3+M2 M2+M1 M2 M1 - - -
M1+M2+M3 M3+M1 M3 M2+M1 M1 - - -
M1+M2+M3 M3+M2 M3+M1 M3 M2 M1 - -
t
1. 2. 3. 4. 5. 6. 7.
Switch-off
De-staging of external motors (M1, M2, M3)