Hitecsa EQPL-B 4360 Manual Del Operador página 84

II.11.1.6 Checking compressor oil level
IMPORTANT!
Do not use the unit is the oil level in the
compressor is low.
The lubricating oil level in the compressor can be checked by means of
the sight-glass. The oil level in the sight-glass can be inspected while all
compressors are running.
At times a small amount of oil could migrate towards the refrigeration
circuit causing slight level fluctuations; they can therefore be considered
normal.
Level fluctuations are also possible when capacity control is activated; in
any event, the oil level must always be visible through the sight-glass.
The presence of foam when the unit starts is normal. A prolonged and
excessive presence of foam during operation, on the other hand, means
that the refrigerant has not dissolved in the oil.
SECTION II :: INSTALLATION AND MAINTENANCE
II.11.1.7 Inspection and washing the exchangers
DANGER!
The acids used for washing the heat exchangers
are toxic. Use suitable personal protective
equipment.
The plate and shell and tube heat exchangers are not subject to a
particular risk of getting dirty in nominal conditions of use. The working
temperatures of the unit, the speed of the water in the pipes/cabinet and
the suitable finish of the heat exchanging surface reduce fouling of the
exchangers to a minimum. Any incrustation of the exchanger may be
detected by measuring the pressure-drop between the inlet and outlet
pipes, using a differential pressure gauge, and comparing the results
with the pressure-drop specified in the tables in the annex. Any sludge
that may form in the water circuit or any silt that cannot be trapped by
the filter, as well as extremely hard water conditions or high
concentrations of any antifreeze solution used, may clog the exchangers
and undermine their heat exchanging efficiency. In this case, it is
necessary to wash the heat exchanger with suitable chemical
detergents. If necessary, provide already existing systems with
adequate charge and discharge connections or by proceeding as
illustrated in the figure. Use a tank containing weak acid: 5% phosphoric
acid, or if the exchangers have to be cleaned often: 5% oxalic acid. The
liquid detergent must circulate around the exchanger at a flow rate at
least 1.5 times higher than the rated working flow rate in any case
following without exceeding the maximum admitted flow (see "Water
capacity limits"). The first detergent cycle cleans up the worst of the dirt.
After the first cycle, carry out another cycle with clean detergent to
complete the operation. Before starting up the system again, rinse
abundantly with water to get rid of any traces of acid and bleed any air
from the system; if necessary start up the service pump.
1. Unit;
2. Auxiliary cock
3. cut-off gate valve;
4. wash pump:
5. filter:
6. acid tank:
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