Controlling The Direct Expansion Evaporator; Controlling The Chiller - Samson TROVIS 5400 Mounting And Operating Instructions

6.11.7 Controlling the direct expansion evaporator

In all systems with cooling coil, the binary output BA4 can be activated dependent on the
control signal Y3. The control signal Y3 is available parallely with this function.
Function
BA4 dependent on Y3

6.11.8 Controlling the chiller

In all systems with cooling coil (not Anl 7), a chiller can be run to overlap, i.e. parallely to
the other system elements operating in sequence. As soon as a low temperature is requested,
the chiller is activated at least for the period determined under Minimum activated time
(START MIN ). The other system elements can be requested parallely to the chiller. An excess
amount of cold air is at first compensated with HRU and heating coil. If the heating coil con-
trol signal Y1 exceeds the value STOP (deactivation of cooling at Y1 >), the chiller is
switched off at least for the time period determined under STOP MIN (minimum deactivated
time). When the outdoor temperature is fedforward, the chiller basically is only enabled
when the outdoor temperature is 3 °C higher than the current set point − with a cascade con-
trol, 3 °C higher than the current supply air set point. A chiller that is running is deactivated
when Y1 > 0 % observing the Minimum activation time (START MIN), if the outdoor tempera-
ture is smaller than the set point; with outdoor temperatures higher than the set point de-
pending on the parameter Deactivate cooling (STOP) . The control signal Y3 is not available.
Function
Controlling the chiller
WE Configuration
OFF Fb12 = ON, option: SEQ
30 %
START (activating value) / STOP up to 100 %
10 %
STOP (deactivating value) / 0 % up to START
WE Configuration
OFF
Fb12 = ON, option: PAr
600 sec
START MIN (min. activation time)/ 0, 60 to 3600 sec
600 sec STOP MIN (min. deactivated time)/ 0, 60 to 3600 sec
50 % STOP (Deactivation of cooling at Y1 >) / 0 to 100 %
Control functions
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EB 5477 EN