Temperature Adjustment In Units With Direct Freecooling; Adjustment Of Split Type Units And Direct Freecooling With Damper; Enabling Direct Free Cooling - Mitsubishi Electric s-MEXT-G00 006 Technical Manual

TM_s-MEXT_ME28relC_00_12_19_EN
11.3

TEMPERATURE ADJUSTMENT IN UNITS WITH DIRECT FREECOOLING

INFORMATION
Parameter P21.21 is set as follows, depending on the type of unit:
•
P21.21 = 33% if the unit has two connected Mr Slim units.
•
P21.21 = 50% if the unit only has one connected Mr. Slim unit.
The parameter can in any case be set using the "Freecooling" menu, which can be accessed by entering the "Service" password.
The temperature adjustment charts are modified as shown in the following paragraphs.
The parameters for configuring the Freecooling function are in the "Freecooling" menu, which can be accessed by entering the "Service" password.
The setpoint and adjustment band values for all the types of units are in the "Freecooling" menu, which can be accessed by entering the "Service" password.
11.3.1

Adjustment of Split Type units and Direct Freecooling with damper

11.4

ENABLING DIRECT FREE COOLING

Enabling Direct Free Cooling is allowed by the difference between external and room temperatures. In case the difference between room and external temperature should be
higher that a set value, the Free Cooling regulation is enabled.
Freecooling OFF
Technical manual
P21.14
P21.13
Step no. 11
Step no. 0
P50.01
P20.18 differential
Figure 11-2: Resource activation chart for Split Type unit with 1 Mr Slim and Freecooling damper
P21.14
P21.13
Step no. 11
Step no. 0
P50.01
Figure 11-3: Resource activation chart for Split Type unit with 2 Mr Slim and Freecooling damper
Figure 11-4: Free cooling use enable chart
Freecooling
damper
Master PAC-IF
card request
50% ambient
Freecooling
damper
Master PAC-IF
card request
T
P21.21
P20.18 differential
P21.11
P21.12
Differential
91
T (°C)
(°C)
ambient
Freecooling ON
T - T
external ambient
TRANSLATION OF THE ORIGINAL INSTRUCTIONS