Application guidelines
22
FRCC.PC.021.A5.22
Operating conditions
The OCS controls the compressor operation
by monitoring high pressure, low pressure and
discharge temperature.
Alarms are displayed when the compressor
exceeds the limits and the control circuit M1-M2
is opened if normal operation is not recovered
within predefined delays (see table below).
Compressor start up is allowed only in starting
areas 1, 2.3 and 3.
During start-up or defrost, the compressor may
operate outside this envelope for short periods.
Transient conditions (areas 2.1, 2.2, 2.3, 3) are
allowed and also monitored by the OCS (see
table below for details).
Transient conditions
-20
0
20
40
60
80
100
120
140
160
-40
-30
-20
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
130
Evaporating temperature (°F)
Co
nd
en
si
ng
T
em
pe
ra
tu
re
(°
F)
2.1
2.2
4
3
4
2.3
1
Area 1: continuous running SH5K to 20K
Area 2.1: 31 s maximum
Area 4: outside map
Area 2.3: 3 min. maximum
Area 2.2: 31 s maximum
Area 3: 3 min. maximum
Discharge pressure warning
Area 1+2.3+3: start/restart map.
