Refrigerant Charge; Fan Speed Control; Servicing And Maintenance; Replacing The Fan - Tecumseh SILENSYS Montageanleitung

■
4.1. Preventing leakage
All connections must be systematically checked for any leakage
with an electronic leakage detector suitable for the type of
refrigerant used. A leak test can be carried out before pulling a
vacuum by using a pre-charge of nitrogen and a leak detection
aerosol (refrigerant tracers not approved) around the joints. Do
not over pressurize the system when using nitrogen. A more
accurate check using an electronic leakage detector can be carried
out after charging with refrigerant.
■
4.2. Pulling a vacuum
Pull a deep vacuum on the installation to about 200 microns
mercury or 0,27 mBar, with a suitable vacuum pump.
We recommend that a vacuum is pulled simultaneously from both
high and low pressure sides of the system to ensure a uniform
vacuum throughout the system including the compressor and to
reduce the amount of time required to obtain the vacuum.
■

4.3. Refrigerant charge

Charge the installation using only the refrigerant for which the
unit has been designed (see identification plate).
Charging with refrigerant will always take place in the liquid phase
in order to maintain the correct blend of zeotropic refrigerants..
Pre charge will be realized on the liquid line. Additional charge will
be conducted on the suction line until obtaining the nominal
operating mode of the installation (installation operation). See
paragraph "Pre-start check list" before powering.
NEVER START THE COMPRESSOR UNDER VACUUM, WHETHER
HBP OR LBP and ensure before starting that the compressor
casing is under positive pressure. We therefore recommend to de
charger lentement le circuit frigorifique entre 4 et 5 bars s'il est au
R-404A et à environ 2 bars s'il est au R-134a.
Pre-start check list
Make sure that:
1. The power supply voltage is compatible with that of the
condensing unit.
2. Electrical safety devices are set correctly for the condensing unit.
3. Service valves are fully open.
4. The crankcase heater is working.
5. Condensing unit fan blades rotate freely.
6. The installation is given a final check for any possible faults.
7. In the case of three-phase scroll compressors, control the order of
the phases of the power supply so that the rotation of the motor
allows the compression of the refrigerant. Reverse 2 phases if
necessary.
8. In the case of the presence of a controller, read the enclosed
leaflet and check the setting values set by default.
9. The design of the refrigeration system must be such that it does
not allow the compressor to start more than 6 to 8 times per hour.
Check list after start up
After the installation has been running for several hours, carry out
the following checks.
1. Voltage and current drawn by the condensing unit are correct.
2. Direction of rotation of Scroll and Rotary compressors.
3. Pressure switch adjustment.
4. High and low operating pressures of the installation are correct.
5. Fan blades are rotating freely
6. Superheat and sub cooling
7. Oil level check for multi piston and scroll compressors
10/40 366430 / 04.2013_b
Installation Instructions |
8. The system is checked again for leaks.
9. For remote installation please refer to the 'recommendations of
use handbook'.
Make sure that the installation is running smoothly.
Carry out a general inspection of the installation (e.g. cleanliness,
vibration and/or unusual noises). Ensure the settings and the
functions of the electrical circuits are correct.
The lack of refrigerant may be characterized by:
- High and low pressure values that are too low
- An evaporator that is partially frozen
- The presence of bubbles on the sight glass.
The excess of refrigerant may be characterized by:
- A high pressure value that is too high
- Over consuming compressor
- Important sub cooling
- A liquid return
■

4.4. Fan speed control

The rotational speed of the fan(s) is controlled by a pressure
actuated fan speed control. Its function is to:
- Prevent an excessive drop in condensing pressure in winter
which would adversely affect the correct operation of the
expansion valve,
- Further reduce noise levels when the ambient temperature allows.
See Appendix 5, page 35 on fan speed control
2 types of commands for compressors assembled in parallel are
possible:
- Piston compressor: a simple contact activated by a thermostat
or pressure controller (operation in pump down).
- Scroll compressor: electronic controller set up in Silensys®
activates on-off control of compressors according to the suction
pressure and running time.

5- SERVICING AND MAINTENANCE

Unauthorized modifications to Silensys® condensing units are
prohibited. Authorization from Tecumseh must be obtained prior
to any modification whatsoever.
Any faulty part must be replaced with a genuine spare part. In
order to maintain the low noise levels of the condensing unit over
time, we recommend replacing the anti-vibration mounts and/or
isolating pads as soon as any change in the noise or vibration level
of the unit is noticed.
Connections, fan and compressor compartments can be accessed
from either the side door panel or the front of the unit, without
removing the lid.
■
5.1. Condenser
The condenser and the condensing unit should be cleaned at least
once a year. Access from the inside of the unit can be gained by
removing the fan cover.
■

5.2. Replacing the fan

- Switch off and isolate the condensing unit.
- Disconnect the fan motor cable from the junction box.
- Undo the 4 mounting bolts.
- Take off the fan motor assembly.
- Replace the fan motor and its capacitor ( size S model).