Procedure For Calibration Of Monitoring Devices; Procedure A; Procedure B; Procedure C - BUSCH COBRA NC 400 B Supplément Au Manuel D'installation Et De Maintenance

Procedure for calibration of monitoring
devices

Procedure A

Dismount the PT100 probe and check it with a calibrated oven or send the
probe to an approved laboratory for inspection.
Reassemble the probe on the pump after checking.

Procedure B

Dismount the pressure sensor and check it by comparing it with a cali-
brated pressure sensor or send the sensor to an approved laboratory for
inspection. Reassemble the probe on the pump after checking.

Procedure C

Dismount the pressure switch and check it by comparing it with a cali-
brated pressure sensor or send the sensor to an approved laboratory for
inspection. The pressure switch must trip at the prescribed alarm value
when the pressure increases. Reassemble the probe on the pump after
checking.

Procedure D

Remove the vibration sensor from the pump and get it calibrated by a lo-
cal calibration service.
Alternatively you can return the sensor for calibration to:
Monitran Ltd
Monitran House
33 Hazlemere Road
Penn
HP10 8AD
UK
info@monitran.com
Use an Analog Current Loop Simulator and Tester 4-20mA to test the
remaining control loop.
Compare and record the trip value, see table alarm values.
After test of the control loop and calibration of the transmitter, mount the
transmitter back on the pump.

Procedure E

Check that the inductive contact changes state when the ball of the
flowmeter is passing without disassembling the flowmeter or its switch.

Procedure F

Check that the level switch changes state by using the test magnet.
• Hold the test magnet against the "target" marking.
• Make sure that the switching status is changed.
• Read the instruction manual of the level switch for more information.

Procedure G

Check that the solenoid valve changes state by electrical supply. Visual
inspection of the solenoid valve sealing by means of the flow meter.
Procedure H
Check that the solenoid valve changes state by electrical supply. Visual
check of the sealing at the outlet of the solenoid valve (no liquid passing).

Start-up

CAUTION
The indications noted in this chapter replace the indications of the
standard installation and operating manuals!
Start-up
Seite/ Page/ Page 18

Vacuum pump

Before starting up the pump, it is essential to have read and
understood the entire installation and operating manual COBRA NC
400 B.
Before operation, the pump must be filled with the relevant gear oil
as well as the appropriate cooling liquid and their levels must be
checked; top up if necessary (see also installation manual).
In case of wrong direction of rotation of the pump, extensive damage
can occur. Press the Start / Stop button only briefly to check the
direc-tion of rotation with the help of the motor fan (see "Electrical
connection").
At temperatures near or below freezing point, the pump must run
with the relevant antifreeze in the cooling system.
After start-up, the vacuum pump has to be checked every day for
any unusual noise. In such cases , the pump must be stopped imme-
diately, see paragraph "Troubleshooting".
Adjustment of the thermostatic valve
and keeping to the temperature class
The temperature class of the vacuum pump is defined for the inside
(i) zone and the outside (o) zone, see the explosion protection group
marking on the vacuum pump and also this installation manual. The
inside zone is in contact with the drawn gases, and the outside zone
with the environmental atmosphere.
In the case of identical temperature classes for the inside and outside
zone, only one temperature class, which will be applicable for both
zones, will be indicated.
The temperature sensor TSA+/ 0102 surveys any rise of temperature
of the cooling liquid, in order to ensure the temperature class is
respected.
WARNING
The temperature class is monitored by the temperature sensor
TSA+/ 0102. The maximum value of the temperature sensor is
defined in the "COBRA ATEX Catalogue".
The monitored values depend on several operating values. In order to
ensure trouble-free operation, the initial adjustments must only be
carried out by Busch specialised staff during the initial start-up of the
pump.
The following operating values have a direct influence on the moni-
tored temperatures:
l Temperature of the gas entry (< 60 °C)
l Cooling medium (water, mixture of water-glycol or thermal oil)
l Differential pressure between the entry and outlet of cooling me-
dium
l Cooling medium temperature
l Pressure on suction side and pressure side
l Frequency used
l Ambient temperature
If an operating value is modified at a later date thereby causing an in-
crease of the gas temperature, the thermostatic valve must be adjus-
ted accordingly.
WARNING
The adjustment of the thermostatic valve is only permissible in
case of absence of any explosive atmosphere.
After the adjustment, the pump has to be operated at a minimum
of 30 minutes without any explosive atmosphere inside.