Operation In An Explosive Atmosphere; Operating Modes - Wilo -Rexa PRO series Einbau- Und Betriebsanleitung

US English
3.2.2. Motor
Single or three phase AC glanded motors are used as
the motors. The motor is cooled by the fluid around
it. The waste heat is transferred directly to the fluid
via the motor housing. The motor may emerge from
immersion during operation.
NOTE
When the motor is non-immersed, observe and
comply with the specifications for "non-immersed
operating mode."
With AC motors, the operating capacitor is inte-
grated in an external capacitor switchgear in the
connection cable.
The connection cable has a length of 40 ft (12.5 m),
is longitudinally watertight, and is available in fol-
lowing versions:
• Cable with plug
• Bare cable end
3.2.3. Monitoring equipment
• Motor compartment monitor:
The motor compartment monitor signals water
ingress into the motor compartment.
• Thermal motor monitor:
The thermal motor monitor protects the motor
winding from overheating. Bimetallic strips are used
for this as standard. The motors can be equipped
with PTC sensors as an option.
The motor can also be fitted with an external pencil
electrode to monitor the sealing chamber. This sig-
nals if there is water ingress into the sealing cham-
ber through the mechanical seal on the fluid side.
3.2.4. Seal
The seal for the fluid and the motor compartment
is made via two mechanical seals. The sealing
chamber between the mechanical seals is filled with
environmentally safe medicinal white oil.
3.2.5. Materials
• Motor housing:
ASTM A48 Class 35/40B (EN-GJL-250)
• Hydraulic housing:
ASTM A48 Class 35/40B (EN-GJL-250)
• Impeller:
ASTM A48 Class 35/40B (EN-GJL-250)
• Shaft end: AISI 420 (1.4021)
• Static gaskets: Nitrile (NBR)
• Seal
• On pump side: SiC/SiC
• On motor side: C/MgSiO4
3.2.6. Attached plug
In the "P" version, a shockproof plug is attached for
single phase AC motors and a CEE-plug is attached
for three phase AC motors.
12
These plugs are designed for use in commercially
available shock-proof or CEE sockets and are not
submersible.
CAUTION: beware of moisture!
Ingress of moisture will result in damage to the
plug. Never immerse the plug in fluid and always
protect it from moisture.

3.3. Operation in an explosive atmosphere

Pumps with the "Ex" marking are suitable for
operation in an explosive atmosphere. The pumps
must meet certain guidelines for this type of use.
Certain rules of conduct and guidelines must be also
followed by the operator.
Pumps that have been approved for use in an explo-
sive atmosphere must be marked as follows on the
rating plate:
• "Ex" symbol
• Information on Ex classification
For use in an explosive atmosphere, observe the
further specifications in the appendix to this
manual
DANGER: from incorrect use!
When used in an explosive atmosphere, the
pump must have a corresponding approval. Also,
the accessories must be approved for this appli-
cation. Check the pump as well as all accessories
before use to verify that they are approved in
accordance with regulations.

3.4. Operating modes

3.4.1. Operating mode S1 (permanent operation)
The pump can operate continuously at the rated
load without exceeding the permissible tempera-
ture.
3.4.2. Operating mode S2 (short term operation)
The maximum operating period is specified in
minutes, e.g. S2-15. The pause must last until the
machine temperature is no more than 2 K away from
the temperature of the coolant.
3.4.3. Operating mode S3 (intermittent operation)
This operating mode defines a combination of pe-
riods of operation and standstill. With S3 operation,
the values given are always calculated based on a
period of 10 minutes.
Examples
• S3 20 %
Operation 20 % of 10 min = 2 min / standstill 80 %
of 10 min = 8 min
• S3 3 min
Operation 3 min / standstill 7 min
PRODUCT DESCRIPTION
WILO SE 2014-11 V05 Letter