Trip Procedure; Shutdown Procedure; Protection Against Explosions - BUSCH COBRA NC 0100 B Supplément Au Manuel D'installation Et De Maintenance

Trip procedure

When a dysfunction occurs on the screw vacuum pump, it should im-
mediately be stopped. Close without delay the suction valve MV1, in
order to avoid the ventilation of the recipient via the screw vacuum
pump and the pump has to be immediately inertised.

Shutdown procedure

l A problem has been indicated by a monitoring element during the
running of the pump
l Close immediately the suction valve MV1 and simultaneously
supply non explosive gas into the flushing gas connection, suction
side
l Switch off the vacuum pump (motor)
l Non explosive gas volume flow :
u NC 0100 B : ³ 25 liter/ min
u NC 0200 B : ³ 40 liter/ min
u NC 0300 B : ³ 75 liter/ min
l Inertise during at least 200 seconds, then close the gas supply and
the inerting is finished
l Switch off the pump, close the valves MV2, MV3, MV5, MV7
Before to restart the vacuum pump, the cause of the problem has to be
found and solved. This is particularly important when TSA+/ 0102,
TSA+/ 0103, PSA+/ 0301 or SA+/ 0701 have indicated the problem.
The vacuum pump should be installed such a way than when the
pump stops, a rear current resp. a reflux of the drawn medium is not
possible.

Protection against explosions

The vacuum pumps COBRA NC 0100 ... 0300 B are conformable to
the European directive 2014/ 34/ EU.
The vacuum pumps are provided with one of the following characteris-
tics for the protection against the explosions:
COBRA NC 0100 B
2G
II
Inside
or 3G
No
Outside
II
ATEX
Zone
1 2 3 4
or
2G
Inside
II or
3G
2G
II
Outside
or
3G
Flushing gas
connection
Gb X
Ex h IIB T4
8
6 7 9
5
Gb
or
T4 X
Ex h
IIB
Gc
Gb
IIB or
T4 or X
Ex h
IIC
Gc
1 Apparatus according to directive 2014/ 34/ EU
Inside and outside of the vacuum pump
2
3 Equipment group II (Not for mining application)
Possible explosive gas atmosphere in normal running inside and outside
(apparatus category 2, for Zone 1) or only in case of dysfunction
4
(apparatus category 3, for Zone 2)
5
Type of protection
Explosion group
6
7
Maximum gas and surface temperature (temperature class T4 = 135 °C, T3 = 200 °C)
8 Equipment protection level
Special conditions for safety utilization
9
For the adjustment of the temperature class, imperatively refer to
"Adjustment of the thermostatic valve (option) and adjustment of the
temperature class".
In the table below, you will find the possible alternative of temperature
classes depending of the cooling system and the maximal motor
frequency:
Cooling
Direct cooling
system
Temperature Max. motor
Type
class frequency
NC 0100 B T4(i/o)
COBRA NC 0200 B
2G
or
II
Inside
3G
II No ATEX Zone
Outside
or
2G
or
Inside II
3G
2G
Outside II
or
3G
The following temperature classes are available
T4(i/o)
–
or
T3(i)/ T4(o)
–
or
T3(i/o)
–
when the vacuum pump is equipped with a direct cooling system. If
the vacuum pump is equipped with a recirculating cooling system, the
following temperature classes are available
T3(i)/ T4(o)
–
or
T3(i/o)
–
For the adjustment of the temperature class, imperatively refer to
"Adjustment of the thermostatic valve (option) and adjustment of the
temperature class".
Recirculating cooling
Temperature Max. motor
class frequency
60 Hz T4(i/o) 50 Hz
Gb
or
Ex h
IIB T3, T4*
Gc
Gb
or
IIB
Ex h T3, T4*
Gc
IIC Gb
or T3, T4* or
Ex h
IIB Gc
Description
Seite/ Page/ Page 15
X
X
X