English; Introduction; Description; Area Of Application - BUSCH COBRA NC 400 B Supplément Au Manuel D'installation Et De Maintenance

English

Introduction

Congratulations on your purchase of the Busch vacuum pump. With
watchful observation of the field's requirements, innovation and steady
development Busch delivers modern vacuum and pressure solutions
worldwide.
These operating instructions contain information for
product description,
–
security,
–
installation and commissioning,
–
maintenance,
–
of the the vacuum pump.
For the purpose of these instructions, "handling" the vacuum system
means the installation, commissioning, influence on operating condi-
tions and maintenance of the vacuum system.
Prior to handling the vacuum system, these operating instructions
shall be read and understood. If anything remains to be clarified
please contact your Busch representative!
Keep these operating instructions and, if applicable, other pertinent
operating instructions available on site.
Please keep the documentation for further reference.

Description

CAUTION
The indications noted in this chapter replace the indications of the
standard installation and operating manuals !

Area of application

The COBRA NC 400 B vacuum pump with the certification
2G
Inside II
Outside II
2G
or
3G
Inside II
Outside II
3G
is certified for drawing explosive gases and vapour mixtures out of and
in zone 1 or zone 2.
The vacuum pump can draw explosive gases or vapours of explosion
group IIB and temperature class T3. On the outside the vacuum pump
is a piece of equipment belonging to the temperature classes T3. Please
also note the switch-off temperature settings.
The vacuum pump should not be used for the handling of explosive at-
mospheres that can auto-destruct or are chemically instable.
The vacuum system can be installed in the Ex environment in zone 1 or
zone 2.
The max. authorised ambient temperature is situated between -20 °C
and +40 °C.
The temperature of the drawn gases must be inferior to 60 °C .
The max. authorised back pressure at the outlet of the vacuum pump is
300 hPa up to an operating frequency of 50 Hz, and 200 hPa up to an
operating frequency of 60 Hz. If there is a risk that this back pressure
could rise above 300 hPa, a pressure switch PSA+/ 0301 must be fitted
at the exhaust. This pressure switch will stop the pump as soon as the
back pressure exceeds the set value.
The vacuum pump should only be used when its material and protec-
tion cover are resistant to chemical and mechanical influences (e.g. cor-
rosion) during operation, in order to maintain the explosion protection
cover. This is particularly applicable for the safety devices, such as the
temperature sensors and pressure switches.General description

General description

The vacuum system consists of a single stage screw vacuum pump, as
well as all the necessary supervisory and monitoring equipment. The
vacuum system is mounted on a robust base frame. The vacuum pump
is equipped with a direct cooling system.
A recirculating cooling system is authorised if the cooling liquid tempe-
rature can be guaranteed to stay within the set values given in
"COBRA ATEX Catalogue".
For vacuum pumps of 2G category:
- a level switch LS-/ 0203 is fitted to the cooling liquid chamber to en-
sure the correct level of cooling liquid.
- an accelerometer/ vibration pickup SA+/ 0701 supervises the condi-
tion of the ball-bearings. These must be changed when the set values
are exceeded.
- a temperature switch TSA+/ 0102 is fitted to the discharge flange
For vacuum pumps of 2G or 3G category:
- a temperature switch TSA+/ 0102 is fitted to the cooling liquid cham-
ber to monitor the temperature of the cooling liquid.
IIB T3 Gb
Ex h X
IIB/
Ex h Gb X
T3
IIC
IIB T3 X
Ex h Gc
IIB/
Ex h Gc
T3 X
IIC
Introduction
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