Grasso
Refri
eration Division
GRASSO SYSTEM CONTROL
Chap. 2 - 26 638660E_chapter2.doc 01.2004/1
2.7.2.14 Low intermediate gas overheat alarm
The intermediate gas overheat is monitored. In case this overheat becomes too low, an alarm is generated. This
alarm does not become active until the start up process of the compressor has been completed and an
additional delay time has expired. The delay time ’dTm alarm dly’ becomes active as soon as the intermediate
gas overheat drops below its alarm limit value during the normal operation of the compressor.
The low intermediate gas overheat alarm function is illustrated in the following diagram.
∆T
m
Intermediate gas overheat
A.. Time characteristic of the
intermediate gas overheat
W.. Warning limit
Al.. Alarm limit
ML W.. Warning active
ML A.. Alarm active
T1.. Delay time ’dTm alarm dly’
3.. Reset of the active alarm
Figure 2.30, Low intermediate gas overheat alarm
Intm dif temp
dTm low alarm
Low warning +
Intm dif temp: Actual intermediate gas overheat in K
dTm low alarm: Alarm limit for low intermediate gas overheat in K
Low warning: Enter the warning value as an offset to the alarm limit in K
<< Limit values 01 >>
dTo alarm dly
dTm alarm dly
Run.hours
dTo alarm dly: Alarm delay time for low suction gas overheat in s
dTm alarm dly: Alarm delay time for low intermediate gas overheat in s
Run.hours: Running hours in h
<< Timer values 01 >>
) For GSC control of the refrigerant injection in the economiser (ECO system) the following settings are
recommended:
Limit values: dTm low alarm = 2.0 K / Low warning = 0.0 K
Timer values: dTm alarm dly = 40 s
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