Monitoring Devices; Components Installed By The Client; General Functional Description; Refrigerant Circuit - GEA Grasso M-Series Operating Manual

Operating Manual | GEA Grasso M-Series
Screw Compressor Packages
The safety valve is designed in accordance with DIN
EN 13136 "Refrigerating systems and heat pumps -
pressure relief devices and associated piping - meth-
ods for calculation".
Safety pressure limiter (350)
Safety pressure limiter with two separate trigger con-
tacts, one of which can only be reset using a tool.
The safety pressure limiter switches off the compres-
sor drive motor if the discharge pressure rises above
the set point.
Switching off pressure 1 = see parameter list
Switching off pressure 2 = see parameter list
If it cannot be ruled out that the liquid refrigerant
might attain more than 90% of the oil separator's vol-
ume, then the customer must install an additional
safety valve to prevent expansion of the liquid in the
oil separator (design in accordance with DIN EN
13136, arranged according to EN 378-2 Annex F).
7.7.12

Monitoring devices

The following operating values will be continually
monitored in a standard screw compressor package:
–
Suction pressure
– Discharge pressure
– Oil pressure oil circuit monitoring
– Suction temperature
– Discharge temperature
–
Oil temperature
– absolute primary slide position
– Motor current
– Suction pressure saturation temperature
– Saturation temperature
of condensing pressure
– Number of running hours
–
Difference between oil and discharge pressures
(oil circuit monitoring)
–
Set point of controled value in °C
– Real point of controled value in °C
– Internal volume ratio
– Used refrigerant
–
Controled value
–
Used options
GEA Refrigeration Germany GmbH | P_261511_1 | Generated 01.04.2015
– Oil pressure after oil filter - optional -
– Differential pressure of oil pressure after oil filter
and discharge pressure (oil filter monitoring) -
optional -
7.7.13 Components installed by the cli-
ent
Warning!
The components and parts the cus-
tomer installs in particular the secon-
dary refrigerant and cooling medium
circuits as well as the oil circuit need
to made from materials suitable for the
fluids flowing through them. Further-
more, in the event of modifications to
the product by the customer, the
effects on the safety devices are to be
checked.
GEA Refrigeration Germany GmbH
does not assume any liability for dam-
age arising and the violation of the
safety regulations which result from
the use of unsuitable materials or
through modification to the product
which is not considered in the original
safety concept.
7.8

General functional description

Screw compressor packages are refrigeration sys-
tem components and serve to compress refrigerants
such as ammonia (or other operating media on
request).
Operation as a heat pump is also possible.
7.9

Refrigerant circuit

The screw compressor draws in refrigerant vapour
via the suction check valve and suction filter and
then discharges the compressed vapour into the
plant via the oil separator and discharge check valve.
The suction-side check valve prevents a sudden
pressure equalisation with the low pressure side of
the chiller, while also preventing reverse rotation of
the screw compressor.
The pressure side check valve prevents refrigerant
from re-condensing in the oil separator.
Description of Design and Function
45