Wilo Economy Notice De Montage Et De Mise En Service page 37

8.4 Decommissioning
If the DEA has to be taken out of service for main-
tenance, repair or other measures, proceed as fol-
lows:
• Switch off the voltage supply and secure to pre-
vent it from being switched on again without
authorisation,
• Close the gate valve upstream and downstream of
the system,
• Shut off the diaphragm pressure vessel at the
throughflow fitting and drain.
• Drain the system completely if necessary.
9 Maintenance
To guarantee maximum operational reliability at
the lowest possible operating cost, we recom-
mend inspecting and maintaining the DEA regu-
larly (see DIN 1988). It is advisable to conclude a
maintenance agreement with a specialist com-
pany or with our central after-sales service
department.
The following inspections should be made regu-
larly:
• Check that the DEA is ready to operate,
• Check the axial mechanical seal of the pump. The
axial mechanical seals need water for lubrication.
A small quantity of it can leak out of the seal. If the
leakage becomes very obvious, change the
mechanical seal.
Check the diaphragm pressure vessel (every
3 months is recommended) to make sure that the
supply pressure is set correctly (see Fig. 2b).
Fault
Pump(s) do not start
Installation and operating instructions Wilo-DEA
Cause
No mains voltage
Main switch "OFF"
Water level in storage tank too low, i.e.
low-water level reached
Low-water level switch has triggered
Low-water level switch defective
Electrodes incorrectly connected or sup-
ply pressure switch incorrectly set
Inlet pressure exceeds switch-on pres-
sure
Check valve closed at pressure sensor
Switch-on pressure set too high
Fuse defective
Motor protection has triggered
Contactor defective
Turn-to-turn fault in motor
CAUTION! Risk of damage!
If the supply pressure is incorrect, the function
of the diaphragm pressure vessel is not guaran-
teed, which increases diaphragm wear and can
lead to system faults.
To do this, depressurise the tank on the water side
(close the flow-through fitting (A, Fig. 2b) and
allow the residual water to drain (B, Fig. 2b). Now
check the gas pressure at the valve (top, remove
protective cap) of the diaphragm pressure vessel
using an air pressure gauge (C, Fig. 2b) and correct
the pressure by topping off with nitrogen as
required. (P = pump switch-on pressure p
N2
less 0.2-0.5 bar or the value according to the table
on the tank, Fig. 3) (WILO after-sales service). If
the pressure is too high, discharge nitrogen at the
valve.
• In the case of systems with a frequency converter,
the inlet and outlet filters of the fan must be
cleaned if they are very dirty.
If the system is out of service for a long period,
proceed as described in 8.1 and drain all the
pumps by opening the drainage plug on the pump
base.
10 Faults, causes and remedies
Faults, particularly those affecting the pumps or
control system, should only be remedied by
Wilo's after-sales service or a specialist com-
pany.
NOTE:
The general safety instructions must be observed
when doing any maintenance or repair work.
Also follow the installation and operating instruc-
tions of the pumps and the control unit.
Remedies
Inspect fuses, cables and connections
Switch on main switch
Check break tank inlet valve/inlet pipe
Check inlet pressure
Check, if necessary replace the low-
water level switch
Check installation or setting and correct
Check default values, correct if neces-
sary
Inspect, open check valve if necessary
Check setting and correct if necessary
Check fuses and replace if necessary
Check set values against the pump or
motor data, measure current values and
correct setting if necessary. Check
motor for defects and replace if neces-
sary
Check and replace if necessary
Check, if necessary replace motor or
have repaired
English
min
31