l message ‘LSA’ shown on the display;
l buzzer activated
P12 = 0 ==> LSA alarm disabled
P10 allows the network solenoid valve to be closed in the event of low superheat (LowSH) and/or low
suction temperature alarm (LSA).
l P10 = 1 (default): the unit that signals the LowSH and/or LSA status, as well as closing the local
solenoid valve, broadcasts the request across the LAN. This enables the closing request to be broadcast
over the LAN to the Master.
To effectively close the network solenoid valve (if available)(P10=1), the solenoid on the Master must be
enabled as a network valve (parameter r7=1), the only type that can accept network requests.
l P10 = 0: the unit that signals the LowSH and/or LSA status does not enable closing of the network and
local solenoid valve.
Fig.5.ae
Ref. Description
T_
SUCT
Suction temperature
P11 LSA: low suction temperature threshold
P12 LSA: alarm delay
Ref. Description
t Time
LSA Protection
LOP Minimum evaporation pressure
This function is useful above all for stand- alone refrigeration units, used to prevent the evaporation
pressure from remaining excessively low for too long. When the evaporation pressure, expressed in
degrees (saturated), falls below the threshold, the LOP protection is activated, which adds an integral
action to normal PID control, specifically devised to be more reactive as regards the opening of the valve.
The PID control remains active, as superheat must continue to be monitored as to avoid flooding the
compressors. The LOP alarm is delayed from the activation of the protection function, both are reset
automatically when the pressure value, in degrees (saturated), exceeds the threshold.
Fig.5.af
80|5. Functions
MPXone +0300086EN rel. 1.0– 04.09.2018
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