Preventing Leakage; Pulling A Vaccum; Refrigerant Charge; Pre-Start Check List - Tecumseh SILENSYS Manual De Instalación

Translated from the original instructi ons |
The disintegrati on of the insulator (glass bead) on one of the
compressor's electricity supply terminals following a physical
impact may create a hole through which the refrigerant and
some oil may escape. If it comes into contact with a spark, this
mix may catch fi re. Regardless of the work being carried out on
the cooling system, simply positi oning the electrical unit cover
correctly will limit this type of risk.
Avoid very corrosive or dusty environments. If the installati on is
shut down for a lengthy period, you are strongly advised to bring
the cooling fl uid into the tank when the condenser unit has one.
The aim of this operati on is to avoid the refrigerant migrati ng
to the compressor and any concentrati on of fl uid within the
lubricant that may cause liquid slugs during recommissioning.
■ ■ 4.1.■Preventi ■ ng■leakage
All connecti ons must be systemati cally 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 detecti on
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 aft er charging with refrigerant.
■ ■ 4.2.■Pulling■a■vacuum
Pull a deep vacuum on the installati on 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 ti me required to
obtain the vacuum.
■ ■ 4.3.■Refrigerant■charge
Charge the installati on using only the refrigerant for which the
unit has been designed (see identi fi cati on 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.
Additi onal charge will be conducted on the sucti on line unti l
obtaining the nominal operati ng mode of the installati on
(installati on operati on). See paragraph "Pre-start check list"
before powering.
NEVER START THE COMPRESSOR UNDER VACUUM, WHETHER
HBP OR LBP and ensure before starti ng that the compressor
casing is under positi ve pressure. We therefore recommend to
de charger lentement le circuit frigorifi que entre 4 et 5 bars s'il
est au R-404A / R-452A et à environ 2 bars s'il est au R-134a /
R-513A.
Pre-start■check■list
The condensing temperature must not exceed 63°C during the
transiti on periods. Keep the condensing unit away from any
heat source.
Make sure that:
1. The power supply voltage is compati ble 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. The compressor must be
at a temperature greater than 10°C before start-up.
5. Condensing unit fan blades rotate freely.
6. The installati on is given a fi nal 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
rotati on 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
| Installati on Instructi ons
enclosed leafl et and check the setti ng values set by
default.
9. The design of the refrigerati on system must be such that
it does not allow the compressor to start more than 6 to
8 ti mes per hour.
Check■list■aft ■ er■start■up
Aft er the installati on has been running for several hours, carry
out the following checks.
1. Voltage and current drawn by the condensing unit are
correct.
2. Directi on of rotati on of Scroll and Rotary compressors.
3. Pressure switch adjustment.
4. High and low operati ng pressures of the installati on are
correct.
5. Fan blades are rotati ng freely.
6. Superheat and sub cooling.
7. Oil level check for multi piston and scroll compressors.
8. The system is checked again for leaks.
9. For remote installati on
'recommendati ons of use handbook'.
Make sure that the installati on is running smoothly.
Carry out a general inspecti on of the installati on (e.g. cleanliness,
vibrati on and/or unusual noises). Ensure the setti ngs and the
functi ons 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 parti ally 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 rotati onal speed of the fan(s) is controlled by a pressure
actuated fan speed control. Its functi on is to:
- Prevent an excessive drop in condensing pressure in winter
which would adversely aff ect the correct operati on of the
expansion valve,
- Further reduce noise levels when the ambient temperature
allows.
See Appendix 5, on fan speed control
2 types of commands for compressors assembled in parallel
are possible:
- Piston compressor: a simple contact acti vated by a
thermostat or pressure controller (operati on in pump down).
- Scroll compressor: electronic controller set up in Silensys®
acti vates on-off control of compressors according to the
sucti on pressure and running ti me.

5- SERVICING AND MAINTENANCE

Unauthorized modifi cati ons to Silensys® condensing units are
prohibited. Authorizati on from TECUMSEH must be obtained
prior to any modifi cati on 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 ti me, we recommend replacing the anti -vibrati on mounts
and/or isolati ng pads as soon as any change in the noise or
vibrati on level of the unit is noti ced.
Connecti ons, fan and compressor compartments can be
accessed from either the side door panel or the front of the
unit, without removing the lid.
please refer to
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