Hazard Caused By Sparking; Hazard Caused By Hot Surfaces; Hazard Caused By Static Charge; Initial Operation - Kessel Stz Instructions D'installation, D'utilisation Et D'entretien

10.4.5 Hazard caused by sparking

Mechanically generated sparks can ignite combustible gases and vapours. In accordance with EN 1127-1,
paragraph 6.4.4 sparks must also be excluded for category 2 in normal operation and fault case. In normal
operation no spark formation is possible due to 昀氀uid cover (medium covering the pump hydraulics). The
penetration or suction of foreign matter (stones, pieces of metal etc.) by the suction connection in the pump
hydraulics is not possible during any expectable failure where the 昀氀uid encapsulation fails, since the pump cannot
draw in any pumping medium nor solids contained in this.
The ex-protected submersible motor pumps are lowered into the automatic coupling device in the aerator
inspection chamber using a drain system with two guide tubes made of galvanised steel between which sliding
claws made of cast iron take over the guidance. The sliding speed is so low at max. 0.1 m/s (10 cm/s) that there
can be no spark formation even under the most unfavourable of conditions. During initial installation, the sliding
claws of the draining device must be lubricated using ball bearing grease to suppress heat and spark formation in
the least favourable case.

10.4.6 Hazard caused by hot surfaces

Hot surfaces can only occur during an expectable failure. Operation-related heating to a maximum of 70% of the
temperature class limit T4 (135°C) is to be expected in this case. If the temperature should reach the temperature
limit due to a failure, however, the temperature monitoring device of the electric motor, which is connected to the
mechanical section (pump) via a joint shaft, automatically disconnects the entire unit permanently from the mains
supply.

10.4.7 Hazard caused by static charge

Electrostatic charge can release ignitable discharge under certain conditions. There are no chargeable isolated
conductive components such as polymers used on KESSEL ex-protected submersible pumps. In addition, there
is an outer connection available for establishing potential equalisation, which must be set up by the operating
company. If further components or elements are installed in ex-zone, the operating company must connect and
earth all conductive parts and substances in accordance with EN 1127-1 section
6.4.7 as the most important measure.
10.5

Initial operation

When all the necessary installation, safety and procedure instructions described above have been taken into
account, the pump system must be put into operation by a quali昀椀ed electrician and tested as follows:
Caution!
To ensure that the preconditions for use of the pump system described under section 2.2 are really ful昀椀lled,
measurement of the input power (kW) must be carried out, and this value must be compared with the data in the
table in Annex 1. Since the pump is initially pumping into an empty pipe system, a larger power consumption is
to be expected at the start of pumping, depending on the height and length. Allow the pump to continue pumping
until power consumption has steadied to a 昀椀nal and stable level. If the power consumption value is within the
given power limits of the motor, the explosion-protected submersible motor pump can 昀椀nally be put into operation.
If the power consumption is found to be outside the given power limits of the motor, the ex-protected pump
system must not be put into operation. In this case, the pump characteristic of the installed pressure pipe must
be calculated and determined. The actual operating point of the system can be determined via the in-house
developed KESSEL pump design program SmartSelect. Please contact a KESSEL AG employee for safe and ex-
conform commissioning.
010-989
Supplement for ex-protected model types
70 / 216 2017/04