Pump Location; Piping Requirements; Electrical Requirements - Lowara ATEX Manual De Instalación, Uso Y Mantenimiento

en - Original instructions
• gas explosion group
Example 1:
- Pump: IIC
- Motor: IIC
- Pump unit: IIC
Example 2:
- Pump: IIC
- Motor: IIB
- Pump unit: IIB

4.1.1. Pump location

DANGER:
Make sure that the supplied equipment is suitable for use in
the classified area (according to Directive 1999/92/EC) and
for the nature of any flammable substances present (gas,
vapour, mist).
According to Directive 1999/92/EC, Category 2 equipment is
suitable for use in Zone 1 and 2 areas only.
This equipment is:
•
not suitable for installation in sites where the danger of
explosion is due to the presence of explosive dust/air
atmospheres.
•
for places with a potentially explosive atmosphere, other
than underground parts of mines and those parts of
surface installations of such mines endangered by
firedamps and/or flammable dust.
Guidelines
Observe the following guidelines regarding the location of the product:
•
Make sure that no obstructions hinder the normal flow of the cooling
air that is delivered by the motor fan.
•
Make sure that any fluid leaks or other similar events will not cause
flooding to the installation site or submerge the unit.
• If possible, place the pump slightly higher than the floor level.
• The ambient temperature must be between -10°C (+14°F) and +55°C
(+131°F).
• The relative humidity of the ambient air must be less than 95% at
+40°C (+104°F).
Contact Xylem or the Authorised Distributor if:
• The relative humidity and/or the ambient temperature are different
from those indicated.
• The unit is located more than 1000 m (3000 ft) above the sea level.
The motor performance may need to be de-rated or replaced with a
more powerful motor.
Pump position and clearance
Provide adequate light and clearance around the pump. Make sure that
it is easily accessible for installation and maintenance operations, see
Figure 10.
Installation above liquid source (suction lift)
The theoretical maximum suction height of any pump is 10.33 m. In
practice, the following affect the suction capacity of the pump:
•
Temperature of the liquid
•
Elevation above the sea level (in an open system)
•
System pressure (in a closed system)
•
Resistance of the pipes
•
Own intrinsic flow resistance of the pump
•
Height differences
The following equation is used to calculate the maximum height above
the liquid level which the pump can be installed:
*10.2 - Z) ≥ NPSH + H
(p + H
b f
Pb Barometric pressure in bar (in closed system is system
pressure)
NPSH Value in meter of the pump intrinsic flow resistance
Hf Total losses in meters caused by passage of liquid in the suction
pipe of the pump
Hv Steam pressure in meters that correspond to the temperature
of the liquid T °C
0.5 Recommended safety margin (m).
Z Maximum height at which the pump can be installed (m)
16
+ 0.5
v
For more information, see Figure
NOTICE:
Do not exceed the pumps suction capacity as this could cause cavitation
and damage the pump.

4.1.2. Piping requirements

Precautions
WARNING:
• Use pipes suited to the maximum working pressure of
the pump. Failure to do so can cause the system to
rupture, with the risk of injury.
•
Have all the connections made by qualified installers in
compliance with the regulations in force.
NOTICE:
Observe all regulations issued by authorities having jurisdiction and by
companies managing the public water supplies if the pump is connected
to a public water system. If required, install appropriate backflow-
prevention device on the suction side.
Piping checklist
Check that the following requirements are met:
• All piping is independently supported, piping must not place a burden
on the unit.
• Flexible pipes or unions are used, in order to avoid transmission of
pump vibrations to the pipes and vice versa.
•
Use wide bends, avoid using elbows which cause excessive flow
resistance.
•
The suction piping is perfectly sealed and airtight.
•
If the pump is used in an open circuit, then the diameter of the suction
pipe is suited to the installation conditions. The suction pipe must not
be smaller than the diameter of the suction port.
•
the suction piping must be larger than the suction side of the pump,
then an eccentric pipe reducer is installed.
• If the pump is placed above liquid level, a foot valve is installed at the
end of the suction piping.
• The foot valve is fully immersed into the liquid so that air cannot enter
through the suction vortex, when the liquid is at the minimum level
and the pump is installed above the liquid source.
• Appropriately sized on-off valves are installed on the suction piping
and on the delivery piping (downstream to the check valve) for
regulation of the pump capacity, for pump inspection, and for
maintenance.
• In order to prevent back flow into the pump when pump is turned off
a check valve is installed on the delivery piping.
WARNING:
Do not use the on-off valve on the discharge side in the
closed position in order to throttle the pump for more than a
few seconds. If the pump must operate with the discharge
side closed for more than a few seconds, a bypass circuit
must be installed to prevent overheating of the liquid inside
the pump.
For illustrations that show the piping requirements, see

4.2 Electrical requirements

•
The local regulations in force overrule these specified requirements.
Electrical connection check list
Check that the following requirements are met:
•
The electrical conductors are protected against overheating, shocks
and vibrations.
•
The power supply line is provided with:
•
A short-circuit protection device
•
A high-sensitivity (30 mA) differential switch (RCD, residual-current
device), to provide additional protection against electric shock in the
event of an inefficient grounding system
• A mains isolator switch with a contact gap of at least 3 mm.
7.
Figure 9.