pag. 5
8 --- Maintenance / Spare parts
F
-
or
safety
reasons,
clear
the
unit
opening
the
switch
QS1
before
performing
any
maintenance
operatios
If installed:
AS THE MICROPROCESSOR CONTROL FEATURES
AUTOMATIC RESTART (AFTER A SUPPLY INTERRUPTION)
IT IS ADVISED TO DISABLE AUTORESTART AND OPEN THE
SWITCH QF1 FOR UNITS IN “NO EMERGENCY COOLING
VERSION,
QF1+QF3
SWITCHES
FOR
UNITS IN
“EMERGENCY COOLING VERSION” WHEN PERFORMING
ANY MAINTENANCE.
S
Every day check the microprocessor control readings for
temperature and, if shown, ambient relative humidity.
S
The Maintenance Programme described below should be
carried out by a skilled technician, preferably working un-
der a maintenance contract.
8.1 --- Routine maintenance
Maintenance program -- Monthly check
FANS
Check that the fan motor rotates freely without any abnormal noise, and ensure that the
bearings are not running hot.
Also check the current absorption.
AIR FILTERS
Check the filter conditions; if necessary clean or replace them.
How to replace:
S
open the middle panel and remove filter cover
S
vertically pull the metal pre---filter out and blow carefully
S
extract the filter from its seat horizontally
S
introduce the spare part
S
close the panel
In very dusty environments perform this check more frequently.
CONTROL
Verify the operation of the CONTROL’s LEDs, display and alarms.
ELECTRICAL CIRCUIT
S
Check the power supply on all phases.
S
Ensure that all electrical connections are tight.
REFRIGERATION CIRCUIT
S
Check the evaporating pressures (to be done by a refrigeration technician).
S
Check the compressor current absorption, its head temperature and the presence of
any unusual noise.
S
Ensure that there is no ice formation on the evaporator.
ATTENTION:
To move manually the damper (unit check, damper movement check), press the clutch (yellow button) on the ac-
tuator and then move the damper.
Do not press the clutch (yellow button) when the actuator is powered!
8.2 --- Extraordinary maintenance
8.2.1 -- Check of the system vacuum and leaks.
Note:
Before proceeding, recover all the refrigerant, according to the
local laws.
1) Switch the unit off (outer switch on OFF) and cut off open-
ing the switch QF1 for units in “no emergency cooling ver-
sion” and QF1+QF3 for units in “emergency cooling ver-
sion”.
2) Remove the panels necessary for inspecting the refrigerat-
ing circuit.
3) Connect a high efficiency vacuum pump to the needle
valves (Schräder) on the gas and liquid lines; also arrange
a connection with a nitrogen bottle.
4) Load the circuit with nitrogen (7 bar/700 kPa). Find pos-
sible leaks in the circuit by soapy water or other specific
product (foaming agents), and repair as necessary.
5) Drain the circuit by a vacuum of 0.3 mbar absolute .
6) After 3 hours check not to have exceeded 1.3 mbar abso-
lute; this condition ensures a humidity lower than 50 ppm
inside the system. If the vacuum is not kept there are still
leaks; repeat the operations from point 4.
8.2.2 -- Refrigerant charge operations.
After having eliminated the humidity from the refrigerating cir-
cuit (see 8.2.1), proceed as follows:
1) Make sure all the unit components are in operating order.
2) By a charge hose, connect the charge cylinder to the liquid
line of the circuit. Drain the substances that cannot be con-
densed from the hose.
Charge the circuit exclusively with the
refrigerant indicated on the identification
label
.
Charge the quantity of refrigerant indicated in Tab. a.
3) Close the main switch QS1 for units in “no emergency
cooling version” and QF1+QF3 for units in “emergency
cooling version” and position the outer switch on ON.
4) Start the compressor.
5) The charge operation can be considered finished when,
keeping the condensation temperature at a steady level
(~ 50
°
C, if necessary partially clog the condensing coil),
no more bubbles appear for at least ten minutes. Check if
the overheating in these conditions is 7
÷
8 degrees.
Overheating calculation
a) With the unit operating in standard conditions,
measure the temperature of the suction line in the point
where the bulb of the thermal expansion valve is
fastened.
b) Detect the evaporation pressure gauge temperature
from a pressure gauge placed on the compressor
suction.
c) Subtract the just obtained temperature value from the
one measured in point a). The difference is the
overheating value.
8.2.3 -- R407C refrigerant units
8.2.3.1 --Features of the refrigerating fluid R407C
At standard temperature and pressure it is a colourless gas with
low toxicity, non---flammable, and it has an allowed exposure limit
value (AEL/TLV) corresponding to 1000 ppm (average value
measured on 8 hours/day). In the event of leakage, air the room
before use.
