First Diagnostics; What To Do If; Maintenance; Maintenance Instructions - Mitsubishi Electric MULTIDENSITY 009 Installations, Bedienungs Und Wartungsanleitungen

MULTIDENSITY
7

FIRST DIAGNOSTICS

7.1

WHAT TO DO IF ...

List of actions to be taken in case of unit fault.
Fault Cause
External
Check that condensing pressure is
m-MOCU
not too low (fan speed too high for
condensing
the external temperature)
unit
Check that the fan is turning
Check the speed reference signal
Check that the air flow is correct
Fan (internal
Check that the filters are clean
unit)
Check that the coil is clean
Check the cold air recirculation
from nearby units
Check that the thermal expansion
Low inlet
valve inside the condensing unit is
pressure
not jammed shut
Check that there are no
obstructed/crushed capillary tubes
Check that the dehydrator filter
inside the condensing unit is not
Cooling
obstructed
circuit
Check that the liquid line is not too
small
Check for leaks
Check the refrigerant charge
Check that valves/taps are closed
Increase the ventilation setpoint
Setting Decrease the temperature setpoint
Check that the machine is not
Incorrect unit
Ambient
undersized for the thermal load for
temperature selection
the air volume handled
too high
Check the probe readings
Faulty
Check for alarms
Setting Increase the temperature setpoint
Check that the machine is not
Incorrect unit
undersized for the thermal load or
selection
the air volume handled
Ambient
Check the probe readings
temperature Faulty
Check for alarms
too low
Check the power supply to the
heaters (if applicable)
Hot
Resources
Check the heater safety
thermostat
Setting Decrease the humidity setpoint
Check that the machine is not
Incorrect unit
undersized based on the latent
selection
Ambient load
humidity too Faulty Check the humidity probe reading
high Check the operation of the
Humidifier
humidifier
Cooling Check that the thermal expansion
circuit valve is working correctly
Setting Increase the humidity setpoint
Incorrect unit Check that the machine is not
Ambient
selection oversized based on the latent load
humidity too
Faulty Check the humidity probe readings
low
Check the operation of the
Humidifier
humidifier
Check the speed settings of the
Setting
fans
Check the power supply to the fan
Check the analogue output of the
Low Air Flow speed reference from the
Fan controller
Check for system load losses
Check the cleanliness of the unit
filters
8

MAINTENANCE

8.1

MAINTENANCE INSTRUCTIONS

OBLIGATION
Both regular and extraordinary maintenance activities must be
carried out by AUTHORISED TRAINED INDIVIDUALS equipped
with all the necessary personal protective equipment.
The machine site of installation must meet all the safety
requirements
The procedures set by the Manufacturer must be followed.
UM_MULTIDENSITY_00_Z_09_20_ML
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Before any kind of maintenance is carried out, the following measures must be observed:

isolate the machine from the power supply using the switch on the back door

hang a "Maintenance - do not switch on" sign on the main switch;

use appropriate personal protective equipment (for example: helmet, insulating gloves,
protective goggles, safety shoes, etc.);

use tools that are in good condition and be sure to be familiar with the instructions
before putting them into practice;
Whenever measurements must be taken or checks performed with the machine running, it is
necessary to:

make sure that any remote control systems are disconnected; be aware that the
software on the machine controls these and can enable and disable the components,
posing a degree of danger (for example, by powering and running the fans and their
mechanical systems, which can drag);

work on the open electrical panel for the shortest time possible;

close the electrical panel as soon as the single measurement or check has been
performed;
Furthermore, the following precautions must always be taken:

the cooling circuit contains pressurised refrigerant gas: all maintenance must be
carried out by qualified personnel with the authorisations or certifications required by
the laws in force;

the fluids in the cooling circuit must not be dispersed in the environment;

never keep the cooling circuit open, as the oil absorbs humidity and deteriorates;

when replacing electronic boards, always use suitable equipment (extractor, antistatic
bracelet, etc.);

if replacing a motor, coils or other heavy components, make sure that the lifting
equipment is suitable for the weight;

do not access the fan compartment without first isolating the machine by means of the
disconnecting switch on the electrical panel and clearly displaying a sign saying, "Do
not operate - maintenance in progress";

always use only original spare parts purchased directly from the Manufacturer or from
official dealers;

before closing and restarting the machine, make sure to remove all tools or foreign
bodies.
The list of scheduled maintenance operations is shown in the next paragraph of this manual.
For each intervention, both of ordinary and extraordinary maintenance, a special form must
be issued and kept by the user.
If a Scheduled Ordinary Maintenance notebook is available on the machine, all the operations
carried out must also be recorded on the same.
8.2

SCHEDULED MAINTENANCE

Carry out all the scheduled maintenance activities at the indicated intervals.
INFORMATION
Failure to carry out regular maintenance will make the warranty null
and void and relieve the manufacturer of all safety related
responsibilities
The scheduled maintenance activity intervals are indicated in the tables on the following
pages.
To "read" the hours of operation, they must be displayed on the microprocessor display.
8.3

GENERAL MAINTENANCE WORK TABLE

WORK TO BE CARRIED OUT
Check for display alarms
Visually check for refrigerant leaks
Evaporating coil cleaning
Check of electric connection tightness
Check for worn or damaged cables and replace as
necessary
Check the noise level of the fan bearings
Check the torque of bolts, moving components and
components subjected to vibration (e.g. fan anti-
vibration devices)
Check the cooling circuit for leaks.
Check for oxidized areas on cooling circuits.
Check the condition of hose pipes and capillary
tubes
28
English
WORK INTERVALS
Start of season
Start of season
Every Every 500
Every 1000 hours
day hours
Every 3 months
Every 2 months


1 a year




(*)


ORIGINAL INSTRUCTIONS