About Nighttime Free Cooling Operation; About The Precool And Preheat Function - Daikin VAM350J7VEB Installer And User Reference Manual

8 Configuration
To route the wiring of the CO2 sensor
a d
b c
b
a CO₂ sensor
b Clamp
c Sealing material
d Bush
e Switch box
f X14A connector
g Screw
1 Remove the screws of the switch box cover.
2 Open the switch box.
3 Follow the same path with the CO₂ sensor wire as the damper
switch (red) and thermistor (black) wires: through the bush
inside the unit and through the left bush in the switch box.
4 Firmly insert the CO₂ sensor wire into the X14A connector.
5 Clamp the CO₂ sensor wire together with the damper switch
(red) and thermistor (black) wires inside the switch box.
6 Cut the accompanying sealing material along the slit. Stick each
piece on top of the sealing material that is attached to the
bushing, in order to seal the gap around the CO₂ sensor wire.
7 Bundle the excess CO₂ sensor wire together with the damper
switch (red) and thermistor (black) wires from the inside of the
unit with the accompanying clamp.
8 Cut off the excess part of the clamp.
NOTICE
To install the heat exchanger rail correctly, the wire MUST
be clamped.
NOTICE
When bundling the wires, make sure to open the control
box completely.
To install the components
1 Close the switch box cover.
2 Install the components. Follow the reverse procedure of
remove the components" on
Installer and user reference guide
38
X5A X6A X12A X11A
J3 J2 J1 JC F2 F1 N/P2 P/P1
f
e
g
c
"To
page 37.
8.5.5

About nighttime free cooling operation

Nighttime free cooling function
The nighttime free cooling function is an energy-conserving function
that works at night, when the air conditioner is off. This reduces the
cooling load in the morning, when the air conditioner is switched on.
This is mainly for rooms that contain office equipment that raises the
room temperature.
40
a
30
b
20
OFF
OFF
c
22:00 24:00
a Outside temperature
b Indoor temperature
c Set temperature
d Operating state of air conditioner
e Operating state of heat reclaim ventilation unit
f Nighttime free cooling operation
Explanation
The unit compares the indoor and outdoor temperatures after the air
conditioning stops running for the night. If the conditions below are
met, nighttime free cooling starts. When the indoor temperature
reaches the air conditioning setting, nighttime free cooling stops.
Conditions
▪ The indoor temperature is higher than the air conditioning setting.
▪ The outdoor temperature is lower than the indoor temperature.
If the above conditions are NOT met, re-evaluation takes place every
60 minutes.
INFORMATION
Nighttime free cooling operation works when the heat
reclaim ventilation unit is off, so it is NOT possible to stop
this function.
Setting 17(27)‑1 sets the number of hours that have to pass before
the conditions for the free cooling function are checked.
Setting 17(27)‑6 sets whether the fan runs in high or ultra high mode
during the free cooling.
Setting 17(27)‑7 sets the temperature.
INFORMATION
This function is NOT possible when the heat reclaim
ventilation unit is NOT linked to an air conditioner.
8.5.6

About the precool and preheat function

When the precool/preheat function is set, the heat reclaim ventilation
unit switches on at the configured time (30, 45, or 60 minutes) after
the air conditioner starts cooling or heating. By default, this function
is off. This function must be set with the controller of the air
conditioner.
If the air conditioner is restarted within 2 hours after it has been
stopped, this function is NOT started.
Setting 17(27)‑2 enables this function.
Setting 17(27)‑3 and setting 17(27)‑9 set the delay for the start of the
heat reclaim ventilation unit.
c
ON OFF
f
h
VAM350~2000J7VEB
Heat reclaim ventilation unit
4P487293-1A – 2018.05