Commissioning The System; Decommissioning The System; Maintenance; Faults, Causes And Remedies - Wilo -COF-2B Installation And Operating Instructions Manual

8.2 Commissioning the system

After completing all preparatory work and per-
forming all checks detailed in Section 8.1, refer to
the switchgear's commissioning instructions for
its parameterisation.
At the discharge side of the pressure-boosting
system, the pressure sensor immediately meas-
ures the pressure and the flow switch monitors
the flow: corresponding signals are transmitted to
the switchgear.
When a fire hose cabinet is opened, the pressure
at the discharge side drops and falls below the
activation level set in the switchgear, and the main
pump activates automatically.
When a fire hose cabinet that was previously open
is closed, the pressure-boosting system stops
discharge. The flow switch at the discharge side
activates and the pump stops automatically.
CAUTION!
Do not allow the pump to operate for more than
one minute with the discharge valve closed.

8.3 Decommissioning the system

If the pressure-boosting system must be decom-
missioned to allow maintenance work, repairs or
the like to be completed, proceed as follows:
• Switch off the main on/off switch and ensure that
the system cannot be reactivated by unauthorised
persons.
• Close the gate valves before and after installation.
• Isolate and drain the diaphragm pressure vessel.
• If necessary, drain the system entirely.

9 Maintenance

Maintenance and repair work must only be carried
out by qualified personnel!
DANGER! Risk of death!
In case of work on electrical devices, there is a
danger of death by electrocution.
Before performing any maintenance or repair
work, disconnect the device or system from the
power supply and make sure it cannot be reacti-
vated by unauthorised persons. In general, only
a qualified electrician/engineer should be
allowed to repair damaged connecting cables.
Fault
At least one of the two pumps
does not start
Installation and operating instructions Wilo-COF-2B
Cause
If the reservoir is in suction mode,
there is possible air intake upon suc-
tion
If the reservoir is in suction mode, it
is possible that the strainer foot
valve is permeable or obstructed
Significant friction losses on the
suction side
Municipal water supply pressure too
low or zero
If the reservoir is in suction mode,
then the negative suction head may
be too great
Suction pipework obstructed or valve
on suction manifold closed
To ensure optimal operational reliability and to
keep operating costs at a minimum, it is advisable
to conduct inspections and maintenance of the
pressure-boosting system on a regular basis (refer
to the pump's instructions and standard EN 806-
5). To do so, the best solution is to subcontract
maintenance work to a specialist firm or our cus-
tomer service.
The following inspections must be conducted on a
regular basis:
• Check that the pressure-boosting system is in
good working order.
• Check the pumps' mechanical seals. The mechan-
ical seals use water for lubrication, small quanti-
ties of which may therefore leak from the gasket.
In case of more substantial leakage, the mechani-
cal seal must be replaced.
• Check (ideally every 3 months) that the dia-
phragm pressure vessel (option or accessory) is
kept at the correct pressure for initial compressing
and that it is impermeable.
Caution! Risk of damage to the installation!
If the initial compressing pressure is poor, the
functioning of the diaphragm pressure vessel
cannot be ensured. This may lead to excessive
wear of the diaphragm and technical failures.
When decommissioning the system for a long
period, proceed as described in Section 8.3 and
drain all pumps by opening the drainage plugs at
the foot of the pump.

10 Faults, causes and remedies

Troubleshooting, particularly of problems relating
to the pumps and switchgear, must be performed
exclusively by a Wilo customer service agent or a
specialist firm.
NOTICE:
When carrying out all maintenance and repair
work, it is crucial that the general safety instruc-
tions are observed! It is also important to follow
the installation and operating instructions for the
pumps and switchgear.
Danger! Risk of death!
Only specialist and appropriately qualified per-
sonnel may perform troubleshooting!
Observe the safety instructions in Chapter 9.
Remedy
Check the impermeability of all connections in the suc-
tion pipework.
Check that the suction strainer is properly submerged in
water.
Check the impermeability of the valve and replace it if
necessary.
Check the friction losses and make sure that they are
compatible with the NPSH of the pumps.
Adjust the system to supply the pressure-boosting sys-
tem from a reservoir.
Ensure that the minimum level of the reservoir is com-
patible with the pumps' NPSH.
Check that the valve is open and clean pipework if nec-
essary.
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