11
The adjustment of the pressure switches is co-ordinated in
order to obtain ‘quasi proportionality’ of the fan speed as the
pressure varies.
The VARICOND system is contained in a metal enclosure fixed
to the side of the condenser and it is suitable for outside
temperatures down to -20°C.
The adjustment of each single pressure switch is carried out as
described in the preceding paragraph ‘ON/ OFF PRESSURE
SWITCH’.
Recommended set point values (factory preset):
SET
DIFF
P1
0V
↔
100V
16,6 bar
3,1 bar
P2
100V
↔
130V
20,3 bar
5,7 bar
P3
130V
↔
160V
21,8 bar
3,0 bar
P4
160V
↔
230V
23,5 bar
2,7 bar
BEFORE CARRYING OUT ANY WORK ENSURE THE
ISOLATOR IS SWITCHED OFF
(switch in position “O”).
MAINTENANCE
•
Regularly check the state of the condenser fins; remove
from them all foreign objects (leaves, feathers, seeds, dust,
etc.) using a jet of water or compressed air.
The heat exchanger fins are made of thin
aluminium sheet and can cause cuts in the event
of the accidental contact.
•
Check that the operation and current absorbed by each fan
is normal and without any unusual noises;
•
Check that the control device is operating normally (see
section CONTROL DEVICES - ADJUSTMENT).
FAULT FINDING
WARNING: BEFORE WORKING ON THE CONDENSER READ CAREFULLY THE SAFETY NOTES AT
THE BEGINNING OF THIS MANUAL.
Operation of the condenser is strictly linked to the working
conditions of the unit to which it is connected and therefore
possible faults which may apparently be attributed do the
condenser could actually be caused by external factors. The
following table lists the most likely faults.
FAULT
POSSIBLE CAUSE
CHECK/ CORRECTIVE ACTION
HIGH DISCHARGE PRESSURE:
A) The heat exchanger fins are dirty
or blocked by foreign objects
Clean the condenser fins following the instructions in the
section ‘MAINTENANCE’
REFRIGERANT
CIRCUIT
B) Cooling air temperature to
condenser too high
1) Check for potential short circuiting of condenser
cooling air
HIGH PRESSURE SWITCH
TRIPS
2) Check the value of the actual cooling air temperature
against the design value for the project
(not dependent on causes external
to the condenser such as:
C) Lack of condenser air flow
Check that the condenser is installed with the minimum
clearances specified (see section ‘INSTALLATION’)
•
non condensing gases in the
circuit
•
valves partially closed in the
section of pipe between the
compressor and the
condenser
D) One or more fans out of service
Check for motor internal protection tripped and if
necessary replace the fan motor
•
suction pressure too high
•
circuit overcharged with
refrigerant with excessive sub-
cooling at the condenser )
E) Control device out of adjustment
or faulty
Check and adjust if necessary the control device (see
section ‘ CONTROL DEVICES - SETTING ‘); replace if
necessary
LOW DISCHARGE PRESSURE
A) Control device out of adjustment
or faulty
Check and adjust if necessary the control device (see
section ‘ CONTROL DEVICES - SETTING ‘); replace if
necessary
B) Refrigerant leak
Locate and rectify the leak and recharge with refrigerant
