Pack Flow Control Valve
General Information (ref A320 AMM)
Each air conditioning pack has a flow control valve which gives variable flow and shut off control. These valves are electro-pneumatically operated.
They will open when the PACK 1 (2) pushbutton switches are pushed in (the OFF legends go off) if the conditions which follow exist:
the engines are not in a starting sequence,
an ENGINE FIRE pushbutton switch is in the normal position (the light in the pushbutton switch is off),
the DITCHING pushbutton switch 13HL is released (the ON legend is off),
the bleed air pressure is more than the minimum pressure needed to open the flow control valves.
Also from A320 AMM (Engine Auto start)
2. Instructions on performing auto start & starting
3. When the engine idle speed is stable, on the ENG panel 115VU:
Set the ENG/MODE/CRANK/NORM/IGN/START selector switch to NORM.
NOTE: It is recommended that the engine operates at or near idle for a minimum of 2 minutes before you increase to high power. You must move the throttle control lever, slowly, carefully and smoothly when possible.
NOTE: You can use taxi time at or near idle as part of the 2 minute warm-up time
Hope this provides some insight stefanoperer
rgds
3m