4.8 Electrical connections
Ensure the electrical supply is disconnected before carrying
out any wiring or repairs of the unit.
Ensure that there isn't any potential flammable atmosphere
after a refrigerant leakage.
All cabling on site must conform with NF C15- 100 in France or
to the current legislation in the country in question (IEC
60204/IEC 60335).
Consider a pollution degree 3, in accordance to IEC60335, to
determine creepage distances and other safety insulation
.
distances
WARNING
To ensure the quality of a TECUMSEH condensing unit, it is
essential to:
- Check that the installation power supply voltage is compatible
with that of the condensing unit (see identification plate).
- Check the compatibility of the wiring diagram with that of the
installation.
- Size the cables (power and control circuits) according to the
specifications of the condensing unit installed.
See table of current ratings in the Electrical Data Instructions
- Ensure that the power supply to the unit is correctly protected
and earthed.
- Ensure that all electrical connections conform to the local
standards and follow recommended best practice.
- Ensure that the unit is earthed when replacing components.
Like the protector, it is vital to use the relay delivered with the
compressor, even if another model seems to be satisfactory at a
given time. All the compressors in the TECUMSEH range are
protected by an external or internal protection mechanism, for
which the principle is based on a current /temperature
combination. Like any protection mechanism, it is normal for it
to disconnect the compressor's power supply outside the
normal usage ranges provided by TECUMSEH.
4.9. Connecting components
Please refer to the wiring diagram (refer to Silensys®' electrical
data instructions
) when connecting components.
- Connect all control and safety devices fitted to the unit.
- Secure wiring using the clips fitted to the condensing unit.
- Close the electrical box after wiring.
5. START UP
Our compressors are designed to operate at a maximum
ambient temperature of 46 °C. Do not exceed this temperature.
To optimize the quantity of refrigerant in the installation,
respect the rules of the art. For the different conditions of use of
the compressor, do not exceed its maximum allowable pressure PS
(see identification label).
If there is a single-walled tube between the water and the
refrigerant (e.g.: water evaporator) and if a leak occurs through
this wall, the refrigerant leaks outside and water enters the
system, creating a vapour effect. Without a safety device, the
compressor will behave like a vapour generator and the motor's
heating will generate a high increase in pressure.
The disintegration 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 fire. Regardless of the work being carried out on
the cooling system, simply positioning the electrical unit cover
correctly will limit this type of risk.
Installation Instructions
Avoid very corrosive or dusty environments. If the installation is shut
down for a lengthy period, you are strongly advised to bring the cooling
fluid into the tank when the condenser unit has one. The aim of this
operation is to avoid the refrigerant migrating to the compressor and any
concentration of fluid within the lubricant that may cause liquid slugs
during recommissioning.
5.1. 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.
5.2. 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.
5.3. 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 charge slowly the
refrigerating circuit to a pressure between 4 and 5 bars if it runs with R-
4554A / R-454C and to 2 bars if it runs with R-1234yf.
Pre-start check list
The condensing temperature must not exceed 63°C during the transition
periods. Keep the condensing unit away from any heat source.
Make sure that:
- Check that the cable gland are properly tightened before starting the
unit.
- Ensure that there isn't flammable refrigerant inside the electrical box.
- The power supply voltage is compatible with that of the condensing
unit.
- Electrical safety devices are set correctly for the condensing unit.
- Service valves are fully open.
- The crankcase heater is working. The compressor must be at a
temperature greater than 10°C beforestart-up.
- Condensing unit fan blades rotate freely.
- The installation is given a final check for any possible faults.
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.
- Fan panel is running
- Voltage and current drawn by the condensing unit are correct.
- Direction of rotation of Scroll and Rotary compressors.
Pressure switch adjustment.
- High and low operating pressures of the installation are correct.
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Translated from the original instructions |