Electrical Connections - Bühler technologies P2.2 Atex Notice De Montage

P2.x ATEX
Install the tubes in a way that the line at the inlet and outlet is
flexible over a sufficient distance (pump vibrates).
The pumps are marked with "In" for inlet (input) and "Out"
for outlet (output). Make sure that the connections to the
tubes are tight.
4.4.1 Monitoring the sample gas pump
NOTICE
When following preventive maintenance according to the
maintenance plan, a crack in the bellows is a rare malfunc-
tion, but cannot be completely eliminated.
NOTICE
If the bellow cracked, turn the pump off immediately!
NOTICE
If flammable gases (even above upper explosion limit (UEL))
or toxic gases are supplied, continuous monitoring of the
pump is mandatory.
DANGER
Explosion hazard, danger of poisoning!
A crack in the bellows when conveying flammable or poison-
ous gasses may allow explosive or poisonous gas mixtures to
leak or develop.
Monitor the pump with a flow- and/or vacuum monitoring
system (see flow diagram).
If a pump defect occurs, shut it off immediately.
4.4.1.1 General monitoring measures
Since a crack in the bellow allows the ambient atmosphere to
be sucked in and the sample gas pump continues to generate
pressure, the bellows of the sample gas pumps must be in-
spected regularly.
In addition, the flow rate of the pump (to the sample gas out-
let) must be monitored with a suitable flow meter.
For more information or Inspecting the bellow the mainten-
ance schedule, please refer to the chapter Maintenance at the
end of the operating and installation instructions.
4.4.1.2 Monitoring measures when conveying
flammable and/or toxic gasses
Conveying flammable and/or toxic gasses further requires
continuous monitoring of the sample gas pump during oper-
ation. This can be done as follows (1) or (2).
1. Flow rate monitor before the pump's gas inlet and after
the gas outlet. A sudden reduction of the suction
volume / flow volume ahead of the pump and consistent
or suddenly increased flow volume after the pump indic-
ates a defective bellow (the pump can convey ambient air
suctioned in due to the tear).
2. Vacuum monitoring before the pump's gas inlet and flow
monitoring after the gas outlet (see illustration). A sud-
den drop in the vacuum before the gas inlet indicates a
defective bellow.
When conveying flammable gasses above the upper explosive
limit (UEL) we further recommend monitoring the lower ex-
plosive limit (LEL) in the installation location.
BX420002 ◦ 04/2021
When conveying toxic gasses we recommend MAC monitoring
(MAC: Maximum Workplace Concentration) at the installation
site.
underpressure
manometer
shut-off valve
sample gas pump
Fig. 1: Sample flow diagram of suitable monitoring

4.5 Electrical connections

WARNING
Hazardous electrical voltage
The device must be installed by trained staff only.
WARNING
Inverter operation is forbidden!
WARNING
Regard National directives concerning installation and opera-
tion of electrical devices in hazardous areas when installing
and commissioning the motor (e. g. EN 60079-14).
CAUTION
Wrong mains voltage
Wrong mains voltage may damage the device.
Regard the correct mains voltage as given on the type plate.
A switch or circuit breaker (per approval) must be installed for
the sample gas pump. It must be easy for the operator to
reach. The switch must be marked as a cut-off for the device. It
mustn't be integrated into a supply cable or interrupt the
earth conductor. It must further separate all poles of the
sample gas pump from live parts.
Only operate the unit with the factory installed motor. The
user must not exchange the unit or replace it with a different
motor.
The sample gas pump must be protected against prohibited
heating with suitable overload protection (protective motor
switch per approval).
Please note the rated current for the protective switch set-
tings (see motor type plate).
Verify the pump motor has the correct voltage and frequency:
Voltage tolerance ±5 %, frequency tolerance ±2 % - from rated
value.
Properly connect the sample gas pump per the respective wir-
ing diagram (see below). If the wiring diagram inside the
cover of the terminal box is different, observe that instead.
The required tightening torque for the nuts on the terminal
board is 1.5 Nm.
Ensure the connecting cable has adequate cable relief. The
clamping area of the cable gland is 6-12 mm. The required
tightening torque for the cable gland is 5 Nm.
manometer
flowmeter
Bühler Technologies GmbH 11