Operation Data Display - Mitsubishi Electric s-MEXT-G00 006 Technical Manual

TM_s-MEXT_ME28relC_00_12_19_EN
The purpose of regulation is to keep the residual ∆P constant when there is an increase in the counter-pressure, with reference to the following graph.
Starting from nominal work point (A), the increase in counter-pressure (due, for instance to a damper closing) causes a shift in the fan work point along the curve towards
point B, with the ensuing increase in pressure. The logic tries to restore the work point by decreasing the speed and move back towards work point C.
To avoid continuous speed adjustment without giving the fan time to adjust to the new speed value and consequently not allowing the pressure transducer to measure the
new differential pressure value, there is a "scan time" that sets the time between the two fan signal variations.
The EC control parameters are under the "Fan" menu, accessible through the "Service" password.
The default values are are the following:
•
Scan time = 60 sec
•
Step voltage = 10 (corresponds to a 0.1V
•
Hyst flow = 25
•
Fan modulation delay = 120 sec
The Fan modulation delay is used whenever the unit is started in order to allow the fan to start. Once this time elapses, speed adjustment begins.
This parameter is in the "Regulations" menu that can be accessed with the "Service" password.
10.5.4

Operation data display

From the main loop, it is possible to open the following masks that display the operation data of the two functions.
Target
02500
Current
00000
Status
Regulating...
Target
0020
Current
0000
Status
Regulating...
Technical manual
Figure 10-8: Constant head fan operation curve
signal increase / decrease).
DC
Constant Capacity operation display mask.
m3/h
m3/h
Constant Residual ∆P operation display mask.
Pa
Pa
TRANSLATION OF THE ORIGINAL INSTRUCTIONS
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