Precise Field Of Application - GEA Grasso VHS Series Installation And Maintenance Instructions Manual

APPENDIX; Product Information (PI)

PRECISE FIELD OF APPLICATION

General limits and fields of operation
Pressure ratio per stage (p
Pressure ratio limits are not absolute
but arbitrary values based on practical
Capacity control, running time fully
4.4 PRECISE FIELD OF APPLICATION
The field of application diagrams as shown in this manual can vary slightly from
the actual field of application for each particular selection.
The actual field of application is dependent on the type of compressor, speed,
suction superheat and part-load steps. For example; longer periods of part-load
operation and/or higher suction superheat as often encountered in booster
compressors result in higher discharge temperatures, reducing the allowable
pressure difference in those scenarios.
15
52
REFRIGERANT
Design pressure
Discharge temperature
/p or p
c o
or p /p )
m o
considerations
Pressure difference
Oil temperature in crankcase
Oil return temperature
unloaded
"PSs" is mentioned on type plate of the compressor (Possibly "Pd" is mentioned for compressors
delivered before 1-Mar-2013)
15
PS * -
s
t
max.
e
/p min.
c m
j
max.
delta-p max.
min.
t
oil
max.
Toil_ret min.
max.
NH
3
26.5 bar(a)
This pressure deviates from the so called
max. discharge pressure=condensing
pressure (allowed during operation) as
stated in the table.
+170 °C
This is the actual discharge temperature,
measured directly in the gas flow just before
the discharge connection.
1.5
10
(p - p ) <= 19.0 bar
c o
The standard built-in overflow safety
valve(s)
(p - p ) <= 25.5 bar
c ambient
o
>30 C and > T
saturated crankcase pressure at stand
+ 15 K
still
Indicated minimum value is the lowest oil
temperature at which the compressor is
allowed to be started.
o
< 70 C, depending on type of oil
The maximum oil temperature depends on
the operating conditions of the compressor
and the oil type used.
A minimum actual oil viscosity of 10 cSt in
the bearings is always required.
>40°C and >Tc+5K] Indicated value is the
lowest return-oil (oil in the oil separator
and/or other oil return source) temperature
at which the return of oil is allowed
When GEA Omni™ controller and oil cooler
are applied 10 minutes; otherwise Consult
GEA
P-NL-094_imm_VHS_English_13
26.07.2021