Grundfos MS1 Installation And Operating Instructions Manual page 7

3. Product introduction
The MS1 and MS1 Ex float switches are ON/OFF
switches. Gold-plated contacts ensure operation at
extra low voltage. The MS 1 float switch is specially
designed for use in wastewater treatment plants and
in pump stations which handle liquids polluted with
solids. Thanks to its good chemical properties, it is
resistant to a wide range of liquids. Resistance list:
raw sewage, fecal discharges, slurry, household
sewage, discharge water from washing machines,
baths and showers, detergents, emulsions
containing petrol, diesel oils, fats, oil, acids etc. rain
water, groundwater, chlorinated water.
The MS1 Ex float switch can be used in a certified,
intrinsically safe-circuit electrical system for the
control and regulation of liquid levels in Zones 0, 1
and 2 Ex- areas. It can also be used in the presence
of gas groups IIA, IIB and IIC, where there is a risk of
explosion when these are in contact with flammable
materials and exposed to temperatures in the range
T1 - T6.
4. Servicing the product
DANGER
Electric shock
Death or serious personal injury
- Before starting any work on the product,
make sure that the power supply has
been switched off and that it cannot be
accidentally switched on.
WARNING
Toxic material
Death or serious personal injury
- Before entering the pit, make sure that
the pit is ventilated according to local
regulations. If not, do not enter the pit.
CAUTION
Biological hazard
Minor or moderate personal injury
- Use gloves and other suitable personal
protection equipment in accordance
with local regulations. Observe local
regulations on exposure to wastewater.
If the float switch is installed and assembled
correctly, it should work practically maintenance-free
for many years. Depending on the level of
contamination in the medium, the system only needs
to be checked from time to time and the float switch
cleaned, if necessary.
5. Technical data
MS1
Housing colour Orange
Cable colour Orange
Specific density (in
0.95 - 1.05
liquid)
Maximum
80 °C
temperature
1-100 mA / 4 V
Breaking capacity
- 5 A / 250 V
Contact SPDT
Switching angle 10 °
Protection system IP68 / 7 bar
Housing material Polypropylene
Cable material TPR/PVC
Height 180 mm
Diameter 100 mm
Cable cross section 3 x 0.75 mm
Ex classification -
Certification -
Ratings -
6. Disposing of the product
This product or parts of it must be disposed of in an
environmentally sound way:
1. Use the public or private waste collection service.
2. If this is not possible, contact the nearest
Grundfos company or service workshop.
The crossed-out wheelie bin symbol on
a product means that it must be
disposed of separately from household
waste. When a product marked with this
symbol reaches its end of life, take it to a
collection point designated by the local
waste disposal authorities. The separate collection
and recycling of such products will help protect the
environment and human health.
See also end-of-life information at
www.grundfos.com/product-recycling.
MS1 Ex
Black
Blue
0.95 - 1.05
80 °C
1-100 mA / 4-40 V
SPDT
10 °
IP68 / 2 bar
PRE-ELEC
Polypropylene
TPR/PVC
180 mm
100 mm
2 2
4G0.75 mm
II 1G Ex ia IIC T6
SEV 18 ATEX 0143
IECEx SEV 18.0015
Ui = 40 V
Ii = 100 mA
Ci = 0 nF + 0.11 nF/m
(connection cable)
Li = 0 μH + 0.35 μH/m
(connection cable)
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