Operation In An Explosive Atmosphere; Operation With Frequency Converters; Operating Modes; Technical Data - Wilo -Rexa NORM Installation And Operating Instructions Manual

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seal. The sealing chamber is filled with environ-
mentally harmless medicinal white oil.
The hydraulics are not self-priming, in other
words, the fluid must flow in either automati-
cally or with supply pressure.
3.2.3. Baseplate
All the individual components are mounted on the
baseplate. The pump is attached to the founda-
tion via the baseplate. Furthermore, the baseplate
contains the motor mount and therefore aligns
the motor shaft to the hydraulic shaft.
3.2.4. Coupling
A Flender coupling is used to connect the hydrau-
lics and the motor.
3.2.5. Monitoring devices
As an option, the sealing chamber can be moni-
tored by an external pencil electrode. This signals
if there is water ingress into the sealing chamber
through the mechanical seal on the fluid side.
3.2.6. Seal
Sealing on the fluid side is achieved by a bidirec-
tional mechanical seal. Sealing on the coupling
side is achieved by a rotary shaft seal.
3.2.7. Materials
• Hydraulics housing: EN-GJL-250 (ASTM A48
Class 35/40B)
• Impeller: EN-GJL-250 (ASTM A48 Class 35/40B)
• Bearing housing: EN-GJL-250
(ASTM A48 Class 35/40B)
• Shaft: 1.4021 (AISI 420)
• Static gaskets: NBR (nitrile)
• Seal
- On the fluid side: SiC/SiC
- On the coupling side: NBR (nitrile)
• Coupling guard: S235JR (ASTM A252, Grade 1)
• Coupling: See instructions from the manufacturer
• Motor: See instructions from the manufacturer
3.2.8. Drive
The pump is driven by IEC standard motors in "B3"
construction. For more information about the
motor and the monitoring devices present, see
the installation and operating instructions for the
motor.

3.3. Operation in an explosive atmosphere

The hydraulics must not be operated in an explo-
sive atmosphere!

3.4. Operation with frequency converters

Operation on a frequency converter is possible.
NOTICE
Also note all the information in the operating
and maintenance manual for the motor!
16

3.5. Operating modes

See the rating plate or installation and operating
instructions for the motor to see the possible
operating modes.
3.5.1. Operating mode S1 (continuous duty)
The motor can operate continuously at the rated
load without exceeding the permissible
temperature.
3.5.2. Operating mode S2 (short-time duty)
The maximum operating period for the motor is
specified in minutes, e.g. S2-15. The pause must
last until the machine temperature no longer
differs from the temperature of the coolant by
more than 2 K.
3.5.3. Operating mode S3 (intermittent periodic duty)
This operating mode defines a combination of
periods of operation and standstill of the motor.
With S3 operation, the values given are always
calculated based on a period of 10 min.
Example: S3 25 %
Operating time 25 % of 10 min = 2.5 min /
standstill time 75 % of 10 min = 7.5 min

3.6. Technical data

The following technical data can be found on the
rating plate:
Max. delivery head:
Max. volume flow:
Rated power required from
hydraulics:
Discharge connection:
Suction connection:
Fluid temperature:
Construction size standard
motor:
Standard speed:
Weight hydraulics:*
* The stated weight includes all components of
the respective version without the motor.
The total weight must be calculated from the
weight of the pump and the weight of the
motor (see rating plate on motor).

3.7. Type key

Example: Wilo-Rexa NORM-M50.218DAH280M6
NORM Series
Impeller shape
V = vortex impeller
M
C = single-channel impeller
M = multi-channel
50 Size discharge connection e.g. 25 = DN 250
21 Performance indicator
8 Characteristic curve number
PRODUCT DESCRIPTION
H
max
Q
max
P
2
X-]
[-X
t
Type key
n
M
hydr
WILO SE 04/2021 DIN A4