Air Delivery For Under Machines; Steam Modulating Humidifier (Accessory); Characteristics Of The Supply Water; Suction Plenum With Damper For Free Cooling (Accessory) - Mitsubishi Electric s-MEXT-G00 Installations, Bedienungs Und Wartungsanleitungen

s-MEXT-G00
2.6.3

AIR DELIVERY FOR UNDER MACHINES

The arrangement of the air delivery system in the raised floor must be defined during the
system design stage.
The useful nominal and maximum static pressure values of the machine are
indicated in the relevant Technical Bulletin.
Pressure drops in the raised floor must be minimal; high values will cause an increase in
electricity consumption of the fans.
2.7

STEAM MODULATING HUMIDIFIER (ACCESSORY)

Submerged electrode steam modulating humidifier with
electronic control, with modulating steam delivery and complete
with safety and operation devices
The metal cover above the boiler ensures high safety levels
during operation.
UL94 Flame resistant safety standard: V0
The accessory includes the combined air return
temperature/humidity probe and the control card.
Water filling and discharge pipes from the humidifier are not
supplied.
It is recommended that a filter and a shut-off tap are installed on
the water filling piping.
This humidifier produces unpressurised steam thanks to the
electrodes submerged in the water in the cylinder: they take the
electric phase to the water, which works as an electric heater
and overheats. The produced steam is then used to humidify
industrial processes or environments through appropriate
distribution systems.
The humidifier's water intake connection is 3/4" G M – ISO 228/1
and it's water discharge connection is 32 mm M smooth pipe.
2.7.1

CHARACTERISTICS OF THE SUPPLY WATER

The quality of the water used affects the evaporation process. The humidifier can be
supplied with untreated water, provided that it is drinking and non-demineralized water.
Hydrogen ion activities
Specific conductivity at 20 °C
Total dissolved solids
Fixed residue at 180 °C
Total hardness
Temporary hardness
Iron + Manganese
Chlorides
Silica
Residual chlorine
Calcium sulphate
Metal impurities
Solvents, diluents, soaps, lubricants
(1) Values depending on specific conductivity; in general: TDS ≅ 0,93 * σ
(2) Not lower than 200% of the chloride content in mg/l di Cl
(3) Not lower than 300% of the chloride content in mg/l di Cl
OBLIGATION
Only use with drinking water.
• There is no reliable relationship between water hardness and
conductivity.
• The water must not be treated with softeners! This can cause
corrosion of the electrodes and the formation of foam, with
possible service irregularities.
• Do not add disinfectants or anticorrosive substances to the
water, as they are potential irritants;
• Well and industrial water, or water from the cooling circuits, is
strictly forbidden, as it is potentially polluted (chemically or
bacteriologically) water.
2.8 SUCTION PLENUM WITH DAMPER FOR FREE COOLING
(ACCESSORY)
The optional allows to obtain free-cooling by direct ambient air intake into the room.
The dampers are proportionally managed by the microprocessor control, that regulates the
quantity of the ambient air to put in the room according to the set-point.
The optional is not suitable for installation in seismic areas.
Ducting for ambient air suction has to be provided by the installer.
A rain cover with grille on ambient air intake, provided by the installer, is recommended.
UM_s-MEXT_G00_01_Z_07_21_ML
Min
Ph 7
σ Μs/cm 300 1250
R, 20 °C
TDS mg/l (1)
R mg/l (1)
180
TH mg/l CaCO 100 (2)
3
mg/l CaCO 60 (3)
3
mg/l Fe + Mn 0
ppm Cl 0
mg/l SiO 0
2
mg/l Cl - 0
mg/l CaSO 0
4
mg/l 0
mg/l 0
≅ 0,65 * σ
R
R, 20 °C; 180
-
-
OBLIGATION
In case of installation in closed ambients, an overpressure damper
is recommended, to allow the air emission during the free cooling
functioning.
2.9

FIRE/SMOKE DETECTOR (ACCESSORY)

This accessory is available as an optional, or it can be bought on-site by the installer.
Position the detector near the unit, but external to the cabinet and in a raised position in
order to obtain an optimal measurement.
To cable it, a shielded cable with minimum section of 0,25 mm
To connect the detector, use the terminals 1 and 155 (by removing the bridge in between)
as a NC contact.
To connect more than one detector (fire detector and smoke detector), use a connection in
series.
To power the detector, on the pins 20 (+) and 30 (-) is available 24 Vdc 150mA max for all
the devices connected.
Max
The maximum reading area for the detector is 40 m
8.5
When the fire/smoke detector trips, the power to the fan is automatically cut off and an
alarm will be sent to the micro, stopping the motocondensing unit.
(1)
Every mentioned connection is also represented in the electrical diagram.
(1)
400
2.10

DAMPER WITH SPRING RETURN (ACCESSORY)

300
In order to prevent any above-limit R32 concentration, the damper with spring return will
0.2
always have a minimum opening gap.
30
2.11

GAS LEAK DETECTOR (NOT SUPPLIED)

20
0.2
The indoor units provides a digital input (dry contact NC) to eventually connect a Leak
100
Detector, in order to set the relevant alarm and provide all the following actions, needed to
guarantee the security in case of leak detection:
0

Bring the fan speed to its maximum
0

Turn off the motocondensing unit

Open the free-cooling damper (if present)
R
To connect the detector, use the terminals 1 and 58 (by removing the bridge in between).
To power the detector, on the pins 20 (+) and 30 (-) is available 24 Vdc 150mA max for all
the devices connected.
Every mentioned connection is also represented in the electrical diagram.
3

PRE-COMMISSIONING

3.1

BEFORE STARTING THE MACHINE

Before contacting the Specialist Engineer, who will execute the first commissioning running
test, the Installer must carefully check that the installation complies with the requirements
and specifications set-out during the design stage, making sure:

that the electrical connection is correct, and that it guarantees compliance with the
current Electromagnetic Compatibility Directive.

that the cooling connection to the condensing unit is correctly terminated;

that there are no leaks in the refrigerant circuit;

that all shut-off valves are open.

For the system charged with R32 refrigerant, ensure that the area is well vented by
opening the air vent/doors or using an external fan.
1. Check that the system master switch is in the ON position.
2. Move the door locking electric switch (on the main panel) to OFF, open the panel
and open the internal electrical panel door.
25
Rain cover
(not supplied)
2
2 .
DOOR LOCKING SWITCH
TRANSLATION OF THE ORIGINAL INSTRUCTIONS
English
Duct
(not supplied)
is recommended.