Construction - Wilo EMU FA Serie Instrucciones De Instalación Y Funcionamiento

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3.2. Construction

The Wilo-EMU FA pumps with dry impeller mo-
tors are submersible sewage pumps, which can
be operated vertically in a stationary wet well
installation and, depending on the motor size, in
both a portable wet well and stationary dry well
installation.
Varying configurations of installation type,
hydraulics and motor can result in different con-
structions.
Fig. 1.: Overview of constructions
1 Various motor sizes
Hydraulics with suspension unit for stationary wet well
2
installation
Hydraulics with pump base for portable wet well
3
installation
4 Hydraulics on base for stationary dry well installation
Fig. 2.: Description of units
1 Cable
2 Handle
3 Motor housing
Seal housing with seal-
4
ing chamber
5 Bearing housing
3.2.1. Hydraulics
The hydraulics housing and impeller are made
of gray cast iron as standard. The discharge side
connection is designed as a horizontal flange
connection. Various types of impeller are used:
• vortex impellers (W)
• vortex impeller with mechanical turbulator (WR)
• single-channel impellers (E)
• multi-channel impellers (Z, D, V)
• SOLID impellers (T)
Depending on the type, the following compo-
nents are also fitted:
• Cleaning hole lid
Opening on the hydraulics housing for removing
blockages in the hydraulics.
• Thrust ring
The thrust ring can be attached to channel impel-
lers and determines the gap between the suction
section and impeller. As the gap becomes larger,
performance decreases and the risk of blockage
increases.
• Stationary wear ring
The stationary wear ring is fitted in the suction
section of the hydraulics and determines the gap
between the suction section and impeller. As the
gap becomes larger, performance decreases and
the risk of blockage increases.
Because stationary wear and thrust rings wear
quickly, they are replaceable. This ensures long
and efficient operation of the hydraulics.
The pump is not self-priming, in other words,
the fluid must flow in either automatically or
with supply pressure.
48
6 Hydraulic housing
7 Suction port
8 Pressure connection
Fastening point for
9
chains with shackle
10 Rating plate
3.2.2. Motor
Three-phase dry impeller motors are used.
The motor is cooled by the fluid around it.
The waste heat is directly transferred via the
motor housing to the fluid. The roller bearings are
permanently lubricated up to size 49 (and size 56)
and are therefore maintenance-free. The bottom
bearing on size 50, and the top and bottom bear-
ing on size 72, must be lubricated.
If the motor is immersed to the top edge of its
housing, it can be used for continuous operation
("S1"). Depending on the size and performance
class, the motor can be used for continuous and
short-term operation ("S2") when it is not in fluid.
For a dry well installation you must also use the
correct operating mode for non-immersed oper-
ation.
Please refer to the rating plate or the enclosed
data sheet for exact details on the operation
mode.
Because condensation can occur in larger motors
due to the heat they produce, sizes 24 and up-
wards are fitted with a separate leakage chamber
for the condensation water. The condensation
water can be drained off if required by the motor
chamber monitor.
DANGER in an explosive atmosphere!
The design of some Ex-rated motors may
mean that the condensation water cannot be
drained, as the drainage screw would violate
the spark-proof area.
The connection cable is watertight along its
length and has free cable ends. The standard
length is 10 m and is adapted for each order.
3.2.3. Sealing
The sealing/bearing housing, with the seal on the
fluid and motor side, is located between the mo-
tor and hydraulics. The seal can be implemented
in various ways:
• Variant "H": rotary shaft seal on the motor side,
mechanical shaft seal on the fluid side
• Variant "G": separate mechanical shaft seal on the
motor and fluid side, in tandem arrangement
• Variant "K": two mechanical shaft seals arranged
face-to-face in a sealing cartridge
Details relating to your sealing variant can be
inferred from the motor designation on the rating
plate, the order confirmation or the technical data
sheet.
A sealing chamber, which is filled with a poten-
tially biodegradable white oil, is located between
the two seals. This catches leaks from the seal on
the fluid side.
Motor types with a bearing housing are equipped
with an additional leakage chamber, which is
normally empty. This catches leaks from the seal
on the motor side.
PRODUCT DESCRIPTION
WILO SE 05/2014 v05 DIN A4