Airwell PAC BT Series, Installation And Operating Manual

Page: 84 / 112

82
Water quality
The water quality is determined by the following factors, avoid
therefore:
- Inorganic salts
- pH
- Biological load (seaweeds etc)
- Suspended solids
- Dissolved oxygen
Water with inadequate characteristics can cause:
- pressure drop increase
- energy efficiency decrease
- corrosive symptom increase
Risk of freeze
If the unit or the relative water connections can be subject to
temperatures close to 0°C adopt measures for prevent risk of
freeze.
For example:
- Mix water with ethylene glycol
- Safeguard the pipes with heating cables placed under
the insulation
- Empty the system in cases of long non-use and check
that: :
- there are no closed taps present that could trap
water even after emptying
- there are no low points in which water can
stagnate even after emptying; carry out any
blowing required
Anti-freeze solution
Consider that the use of anti-freeze solution determines an
increase in a pressure drop.
Make sure that the glycol type utilized is inhibited (not
corrosive) and compatible with the hydraulic circuit
components (pump etc).
PAC BT is designed to ensure the best comfort and energy
efficiency levels. To maintain these high values is necessary
to consider the system details that could adversely affect on
PAC BT performances.
In particular:
- the length of the refrigerant piping should be as small as
possible ;
- to realize a path of the pipes as straight as possible by
limiting the presence of curves;
- properly insulate pipes;
- properly load the refrigerant system.
An incorrect sizing can cause damage to the compressor or
variations in the cooling capacity .
When cut-off parts (solenoid valves, taps etc) are installed
pay attention to the possible formation of traps for the
refrigerant, meaning closed zones up or downstream in which
the refrigerant is unable to expand freely.
With an increase in temperature under these circumstances
(exposure to the sun, ducting close to heat sources etcs) the
expansion of the trapped gas could cause an explosion in the
refrigerating ducting. Evaluate the possibility of installing a
safety valve especiallly in the ducting of the liquid which is
exposed to the most risk.
The operations must be carried out by an expert
refrigerationist .
Avoid curves with a too small curving radius.
Avoid squashing the pipes.
Provide anchoring rods to support the ducting (the weight
11 - GENERAL INSTRUCTIONS
11.5 - PIPE LINES
11.4 - ELETTRIC SYSTEM
General
The characteristics of the electrical lines must be determined
by specialized personnel able to design electrical installations;
moreover, the lines must be in conformity with regulations in
force. Please refer to the "Information" section for the detailed
characteristics of the unit (dimensioning, performance, etc) .
Operate in compliance with safety regulations in force .
Use single protection devices : gloves, glasses ecc.
The protection devices of the unit power line must be able to
stop the presumed short circuit current, whose value must be
determined in function of system features. The power cables
and the protection cable section must be defined in
accordance with the characteristics of the protections
adopted. The serial number label reports the unit specific
electrical data, included any electrical accessories.
The electrical data indicated in the technical bulletin and in the
manual refer to the standard unit, accessories excluded.
Refer to those data.
Connection
All electrical operations should be performed by trained
personnel having the necessary requirements by the
regulations in force and being informed about the risks
relevant to these activities.
Refer to the unit electrical diagram (the number of the diagram
is shown on the serial number label).
Verify that the network has characteristics conforming to the
data shown on the serial number label .
Make sure that the unit supply line is selected at start.
Shelter the cables using adequate measure fairleads.
Before starting work, verify that the sectioning device at the
start of the unit power line is open, blocked and equipped with
sign warning.
First create the earthing connection
.
Prior to powering the unit ensure that all the protections that
were removed during the electrical connection work have
been restored.
Signal lines/data-lay
Do not overpass the maximum power allowed, which varies,
according to the type of signal.
Lay the cables far from power cables or cables having a
different voltage and that are able to emit electromagnetic
disturbances.
Do not lay the cable near devices which can generate
electromagnetic interferences.
Do not lay the cables parallel to other cables; cable crossings
are possible, only if laid at 90°.
Connect the screen to the ground, only if there aren’t
disturbances .
Guarantee the continuity of the screen for the entire extension
of the cable.
Respect impendency, capacity and attenuation indications.