Stulz C2020 User Manual

EN/07.2013/58/96
Conditions to enable the Free-Air fan: Conditions to disable the Free-Air fan:
If ((Fan Speed ≥ M138) and (Fan Speed > 0)) If (Fan Speed = 0)
The Free-Air fan speed is limited by the parameters M138 and M139 as described below:
If (Fan Speed < M138), Fan Speed = M138
If (Fan Speed > M139), Fan Speed = M139
Two control mode are available: P control and PI control.
P Control
The parameters involved are:
– S01 COOLING SET POINT: pre-set = 25 °C
– S06 COOLING BAND: pre-set = 5 °C
– M137 FREE AIR FAN CONTROL MODE: pre-set = 0
– M140 FREE AIR FAN START VALUE: pre-set = 0
– M141 FREE AIR FAN MAXIMUM VALUE: pre-set = 100 %
P control mode can be enabled by setting parameter M137 to 0.
When P control mode is enabled, the behaviour of Free-Air fan speed is as described below:
If: SPEED:
(TI≤(S01+S06*(M140/100))) 0
(TI≥(S01+S06*(M141/100))) 100 %
((TI>(S01+S06*(M140/100))) and (TI<(S01+S06*(M141/100)))) (100/(M141-M140))*((((TI-S01)*100)/S06)-M140)
PI Control
The parameters involved are:
– S01 COOLING SET POINT: pre-set = 25 °C
– M137 FREE AIR FAN CONTROL MODE: pre-set = 0
– M142 FREE AIR FAN PROPORTIONAL BAND: pre-set = 20 °C
– M143 FREE AIR FAN INTEGRAL TIME: pre-set = 200 Sec
PI control mode can be enabled by setting parameter M137 t o 1.
When PI control mode is enabled, the behaviour of the Free-Air fan speed is determined by parameters S01, M142
and M143.
Note that when the freecooling damper control mode is set to PI, the set point of the freecooling damper is equal to
S01+(M31/100)*S06.
Compressor
In night mode the compressor is disabled.
Air change mode
The parameters involved are:
– M144 ENABLE AIR CHANGE: pre-set = NO
– M145 FREE AIR FAN SPEED IN AIR CHANGE MODE: pre-set = 50 %
Air change mode can be enabled by setting parameter M144 to YES.
When air change mode is enabled, the Free-Air fan is enabled for 15 minutes at a speed equal to M145 every 8 hours
of non-functioning (Free-Air fan disabled).
The air change mode cannot be enabled when the Free-Air fan is blocked or the unit is in a state different from ON
(stand alone mode).

Stulz C2020 Specifications

General

Brand	Stulz
Model	C2020
Category	Controller
Language	English