Adjustment Of Oil Pressure; Checking The Direction Of Rotation Of The Drive Motor; Mounting The Coupling; Fig. 46 Motor Direction Of Rotation - GEA Grasso M-Series Operating Manual

Start-up
8.5.9

Adjustment of oil pressure

Danger!
The oil pressure being set too high or
too low may result in serious compres-
sor damage or even total breakdown
of the compressor after even a short
period of operation!
Before the compressor drive motor and therefore the
unit can be started, the oil pressure must be set cor-
rectly by adjusting the oil pressure regulating valve
(075).
For adjustment solely the oil pump must be started.
For units with the control GEA Omni, digital output
must be forced for this.
The set value of the oil differential pressure should
be taken from the P+I flow chart of the specific
project.
Oil differential pressure = oil pressure item (110)
- discharge pressure item (105)
The differential pressure can be changed by rotating
the spindle on the oil pressure regulating valve (the
differential pressure is increased by turning it
inwards and vice versa). To do so, the seal on the oil
pressure control valve (075) must be removed.
In comparison to normal operation conditions, the oil
differential pressure can be slightly higher if only the
oil pump is operated or if the operating temperature
is not reached yet (with the valve open to the same
degree).
In this case, the oil differential pressure should be
readjusted (according to the value in the P+I flow
chart) after start of the unit and reaching of the oper-
ation temperature.
8.5.10 Checking the direction of rotation
of the drive motor
Warning!
The coupling must not yet connect the
motor and compressor!
– Secure the electric switchgear so as to prevent
the compressor drive motor from being switched
on accidentally.
– With the control slide in the MIN or MAX position,
it should be possible to rotate the compressor
shaft easily and smoothly by hand. When check-
ing the direction of rotation of the compressor
driving motor pay attention to the conditions for
switching the compressor on.
62
fig.46: Motor direction of rotation
A Compressor
B Motor
– The compressor drive motor is started directly
and then switched off again by forcing the digital
outputs.
Hint!
Prior to the start-up of the compressor
drive motor, the manufacturer's infor-
mation, e.g. on the lubrication of the
motor, must be followed at all costs.
– If the direction of rotation of the motor is incor-
rect, it should be corrected while the electric
switchgear is secured to prevent the motor from
being switched on accidentally. Then the motor
must work for at least 1 hour, unencumbered
and free from errors. This is important in order to
dry out residual moisture in the motor (caused
during transport or storage).
– The coupling protection must be in place during
this start-up period as required by the labour
safety regulations.
– After checking the direction of rotation of the
drive motor, the coupling may be connected with
the motor.
8.5.11

Mounting the coupling

1. The electric switchgear is secured to prevent it
from being switched on accidentally.
2. Mount the coupling while observing the instruc-
tions of the separate documentation.
3. The values for radial and angular deviations
given in the coupling documentation must be
checked and corrected if necessary. The axis
distance between the compressor drive motor
and the compressor must be checked.
GEA Refrigeration Germany GmbH | P_261511_1 | Generated 01.04.2015
Operating Manual | GEA Grasso M-Series
Screw Compressor Packages