Note
Secochem-Ex
6
2.10.1 Marking
Motor (electric)
II 2G Ex de IIC T.. Gb
Temperature class (T..):
T6, T5, T4 or T3
The temperature class for the Secochem-Ex (SCX) model
supplied depends on pump selection and is indicated in the
data sheet and on the pump name plate.
In case of special coatings with a total film thickness
exceeding 0.2 mm:
II 2G Ex de IIB T..Gb.
Hydraulic system (mechanical) II 2G c TX
Note:
DIN EN 13463--1, 2009--07, section ”9.3.2 Marking of
equipment complying with this standard”, stipulates that
pumps must be marked ”TX”.
Reason:
Where the actual maximum surface temperature depends
not on the equipment itself but mainly on operating
conditions (like a heated fluid in a pump), the manufacturer
must not apply a temperature class or temperature
marking. In such cases, the note ”TX” must be included in
the marking, and the relevant information must be
contained in the operating manual.
2.10.2 Unit fill
It is assumed that the system of suction and discharge
lines and thus the wetted pump internals are completely
filled with the product to be handled at all times during pump
operation, so that an explosive atmosphere is prevented.
If the operator cannot warrant this condition, appropriate
monitoring devices must be used (Directive 94/9/EC,
Annex II, Section 1.5.5 and EN 1127-1).
In addition, it is imperative to make sure that the
rotor space is properly filled (particularly if
barrier liquid is used or filters are fitted upstream of the pump).
The same applies to heating and cooling systems.
2.10.3 Drive
The canned motors may be connected to electrical low-voltage
grids with nominal voltages and voltage tolerances to IEC 38 or
other grids or power supply facilities with max. nominal voltage
tolerances of +/- 10 %.
For explosion--proof pump sets, the maximum permissible
supply voltage deviation is
¦
5 % of the rated voltage. The
voltage difference between the individual phases must not
exceed 1 %.
Appropriate steps shall be taken to protect the canned motor
against overload. Motor overload protection can be realized by:
Limiting the current (e.g. by means of a motor protection
switch)
In this case, the rated current (see Fig. 1, name plate) must
be set. The running motor must be cut out at 1.2 times the
rated current at the latest (EN 60079-14).
Limiting the temperature by means of PTC resistors
integrated in the stator.
The PTC resistors must be connected to a tripping unit
which meets the requirements stipulated by Directive
94/9/EC, Annex II, Section 1.5.5 and EN 1127-1.
Exception: not permitted for motor DE90.2--1,1 in
combination with temperature class T6; for this
combination, motor overload protection by means of a
motor protection switch is mandatory.
When reaching the temperature limit stipulated for compliance
with the temperature class, the canned motor must be cut out
by means of an approved tripping unit (to Directive 94/9/EC)
connected to the measuring points provided.
The following measuring points are provided on the motor:
Monitoring concept I:
Temperature sensor in the bearing carrier (Part No. 382,
see general assembly drawing in the annex)
or
Monitoring concept II:
PTC resistor on the can and/or in the stator (fitted in the
factory).
The cutout temperature indicated on the name plate (T
EX
) must
be adhered to without fail.
In the case of monitoring concept I
(field T
EX
shows a number, see illustration of name plate)
the temperature sensor in the bearing carrier must be
connected and the cutout temperature (T
EX
) must be set.
In the case of monitoring concept II
(Field T
EX
does not show a number, see Fig. 1, name
plate.)
the PTC resistors must be connected to a tripping unit (as
per Directive 94/9/EC, see above).
Cut-out temperature
of PT100
(number or --- )
Rated current
Explosion
protection
marking: Hydraulics
Explosion
protection
marking: Motor
Fig. 1 Name plate
The canned motors can also be operated on frequency
inverters. Make sure to observe the design data of the motor in
this case. To prevent an inadmissible heat build-up in the motor,
always use the motor version with PTC resistors integrated in
the stator when operating the pump unit with a frequency
inverter. The PTC resistors must be connected to a tripping unit
(also refer to sections 5.6 and 4.3.4).
If standstill heaters are used, make sure that the surface
temperatures of the canned motor do not exceed the
temperature class stated on the name plate.
The standstill heater offered by KSB is suited to the canned
motors described in this manual. Please observe the operating
manual supplied with the standstill heater.
2.10.4 Checking the direction of rotation
(see also 6.1.2)
If the explosion hazard also exists during the installation
phase, the direction of rotation must never be checked
by starting up the unfilled pump unit, even for a short period, to
prevent temperature increases resulting from contact between
rotating and stationary components.
2.10.5 Pump operating mode
Make sure that the pump is always started up with the
suction-side shut-off valve fully open and the discharge-side
shut-off valve slightly open. However, the pump can also be
started up against a closed swing check valve. The
discharge-side shut-off valve shall be adjusted to comply with
the duty point immediately following the run-up process (see
6.1.5).
