Chicago Pneumatic CPVS 40, CPVS 60, CPVS 50 Commissioning, Preparation for start-up See Section

D - Commissioning

1 - Preparation for start-up (See Section 3).

ATTENTION

The power circuit will have to be cut off when adjusting the electrical equipment or if inadvertent start-up is to be avoided.

Before start-up, check the following points: 1 - Ensure that the unit has a suitable earth, 2 - Check the oil level in the compressor,

NOTE: the tank was filled in the factory with a suitable oil. See Section 8 - A for the quality of oil to be used and for the oil renewal conditions.

3 - Check that the drainage valve is properly closed.

4 - Make sure that the conveyor assembly's blocking lugs (compressor) have been removed from the compressor silentblocks.

ATTENTION

The oil filler plug, the valve and the drainage plugs have always to be closed during operation and must never be opened before the system has reached atmospheric pressure.

2 - Control of rotation direction on start up

This control must be implemented when the machine is put into operation for the first time, after any work has been carried out on the motor and after any changes to the mains supply.

IMPORTANT :

•Check the direction of rotation (as per the arrow shown on the sump) by jogging over with the START button.

If it is incorrect, swap over two of the motor's phase cables under the drive.

When rotating in the right direction, the oil level (fig. 19) must drop after 4 to 5 seconds of operation.

•Also check the direction of rotation of the fan for air-cooled plants (counter-clockwise, as seen from inside the casing).

1 - Press the START button so that the motor starts.

2 - Allow to rotate for several seconds with the discharge valve slightly open to observe the compressor at load.

3 - Press the STOP button. The motor stops and the plant automatically returns to atmospheric pressure.

3 - Setting of pressure - machine

(Refer E Section 1 refer also to the AIRLOGIC controller manual)

The unit is factory pre-set for a given delivery pressure. As an energy saving measure, it is strongly advised to reduce the pres- sure to the exact requirement by adjusting the "Set point 1"setting.

The stop pressure"Indirect shutdown"used when running at less than the minimum flow-rate - must be set to 7.25 PSI above that of the "Set point 1". In this way, the current used by the compressor is minimised (seenotice AIRLOGIC).

Do not set the stop pressure at a level beyond the machine's max P.

4 - Assembly and settings for parallel operation with other compressors

Pressure for the CPVS compressor must be adjusted at a value within the range of adjustment values for the rest of the compressors..

Adjustments pressure

Stop P

Set point 1

Various compressors

CPVS C1 C2 C3

5 - Regulating the pressure by changing the speed

This method of regulating the pressure allows precise adjustment of the compressor's flow-rate at the compressed air demand valve:

The accuracy is of the order of 1.45 PSI when pressure regulation is achieved by changing the speed, provided that the flow-rate lies between the maximum and minimum rates for the machine.

•The principle of the pressure regulation by changing the speed

The AIRLOGIC controller controls the motor and the compressor as a function of the system pressure as measured by an internal pressure sensor (fig. 14a).

- If the mains pressure is weaker than the pressure set point

(user-defined parameter in the AIRLOGIC) the motor will accelerate and the pressure will increase (fig. 14b)

-If the mains pressure is stronger than the pressure set point, the motor will slow down causing the pressure to drop.

The AIRLOGIC provides the compressor control functions and also controls the whole pressure feedback loop. It therefore includes a device to compare the indicated pressure with that from the pressure sensor, associated with a compensating device, Proportional integral control PI (fig. 14c).

The drive, a result of the latest developments in power electronics, is one of the smallest in size on the market, thanks to its use of high cut-out frequencies with IGBT transistors.

At the same time, the motor control method known as "open loop vector flux control " provides good stability for the system against disruption.

In this way, the pressure feedback loop is more stable to sudden changes in consumption (changes in the flow-rate).

Chicago Pneumatic Compressors	01/2008
62 305 258 65	Page 17