52 | EngliSH
In the case of enclosed spaces of shafts, sufficient
ventilation must be ensured before starting work in
order to thus prevent the existence of explosive ga-
ses.
HOMA explosion-protected equipment must only be
used in areas (potentially explosive atmospheres)
which are applicable for their declared equipment
group II and category 2G, as well as maximum sur-
face temperature of 135°C for temperature classifi-
cation T4 (for frequency converters operation 200°C
for temperature classification T3) in accordance with
IEC 60079-0 for gases and explosion groups A and B.
Installation information for the electrical part
Caution! It is absolutely necessary that, in addition to
this instruction manual, attention is also paid to the
information in the EU type examination certificate in
the Appendix as is mentioned here again.
10.5.1. Electrical connection
The connection of the power cables may only be carried
out inside the potentially explosive areas by means of sui-
table ex-tested and certified terminal boxes.
10.5.2. Monitoring arrangements
Additional and monitoring arrangements with suitable ve-
rification and explosion protection labeling are to be selec-
ted according to the conditions at site. Monitoring units
must satisfy the requirements of the ATEX 100a, Appen-
dix II, Sections 1.5.5 and EN 1127-1 (potentially explosive
atmospheres - Explosion protection - Part 1: Fundamen-
tals and methods). In the case that in the explosion-pro-
tected submersible motor pumps electrical monitoring
sensors are installed outside the enclosed chamber, then
their control circuits must be carried out inside the motor
by the manufacturer in the ignition protection type intrin-
sic safety „i“ according to EN 60079-11:2007.
A potential equalization is installed in the whole intrinsical-
ly safe circuits. A further grounding of the ex-intrinsically
safe circuits is not permissible. The use of this equipment
may only be carried out in the ex-area of the device group
II category 2 when certified ex-intrinsically safe electrode
relays are used and an intrinsically safe circuit of the igni-
tion protection type EX [ib] with the following values has
been used:
•
Ui = 28 V max
•
Ii = 300 mA max
•
Pi = 1.3 W max
The effective internal inductivity Li and the capacity Ci are
negligibly small. In automatic operation with float swit-
ches, these must be installed according to VDE 0165 as
intrinsically safe circuits in the ignition protection type
intrinsically safe „i“ and connected to an ex-intrinsically
safe transistor relay.From motor sizes AM303 there is
built in as standard and in accordance with previously de-
scribed protective measures, each a conductivity probe
and a magnetic buoyancy floating switch (only for vertical
operation) in the oil bearings. A temperature excess above
130°C (T4) at the seals as well as at the housing surface
is safeguarded according to the measures mentions in
Section 4.3!
Caution! In ex intrinsically safe circuits the instru-
ment lines are marked in blue.
10.5.3. Operating off the grid
It is also absolutely necessary that for operating off the
grid to install with thermally delayed excess power trig-
gers also temperature limiters with the strand designa-
tions T1 and T2 to the controls in accordance with the
connection diagram!
10.5.4. Frequency converter operation
For frequency converter operation it is absolutely neces-
sary to install an arrangement for direct temperature mo-
nitoring. This consists of a PT thermistor built into the coil
according to DIN 44 082 and a function-tested triggering
device according to RL 94/9/EG.
The excess power protection arrangement is to be seen
here as additional monitoring. The power limitation of the
converter is set at the highest to 3 x the motor current.
10.5.5. Potential equalization
It is possible for equalization flows (stray or leakage cur-
rents) to flow intermittently or continuously in electrically
conducting plants or components. For this purpose it is
necessary to install a potential equalization in accordan-
ce with EN 60079-14. On the ex-protected HOMA sub-
mersible motors there are installed an outer connection
of min 4 mm2 to max. 6 mm2 for creating a potential
equalization. Further application information for this is to
be taken from the applicable country explosion protection
ordinances.
Installation information for the mechanical part
Caution! The fluid cover of the pump hydraulic must
be monitored by a leveling control!
10.5.6. Danger due to spark generation
Mechanically generated sparks can ignite flammable ga-
ses and condensates. According to EN 1127-1 Para. 6.4.4,
sparks must also be excluded for category 2 in normal
operation. In normal operation no spark generation is pos-
sible due to fluid covering (medium covering of the pump
hydraulic). The ingress or suction of foreign bodies (sto-
nes, pieces of metal, etc) through the suction nozzles into
the pump hydraulic is not possible in an expected case
of malfunction in which the enclosure fails as the pump
cannot suck up pumping medium nor its containing solids.
In the ventilated shaft, the explosion-protected submer-
sible motor pumps are drained via a drain system with
two guide tubes of galvanized steel, between their guide
claws of grey cast iron that guide it into the automatic cou-
pling arrangement. The guide velocity, with max 0.1 m/s
(10 cm/s) is so low that no sparks can be generated even
in the most disadvantaged conditions. In the first installati-
on, the guide claws of the drain arrangement should be lu-
bricated with ball bearing grease in order to suppress heat
and spark generation in the most disadvantaged case.
