Bringing Into Service - Homa CR 253 W Originalbetriebsanleitung

between the two possible pivots. You can shorten the
float arm at this point. In no event may the float with cable
simply be thrown into the conveyed liquid, since correct
switching on and off is possible only when the float ro-
tates around the pivot of the float arm. Possible conse-
quences of non-compliance include flooding (pump does
not switch on), or destruction of the pump by running dry
(pump does not switch off).
If a separate float is used for pump start, pump stop and
alarm, the switching levels are to be selected as above.
The alarm float should switch approx. 10 cm above the
pump switch-on point, but always below the intake.
Important: After any alteration of the float fastening,
faultless operation of the float switch is to be checked
without fail by means of a trial run.
No. Description
1 Notch to reduce the float switch
2 Fixing screw
Float circuit for intercoupling
Pumps without a float switch can be retrofitted with a
HOMA float circuit for intercoupling. The electrical con-
nection is made by intercoupling the float circuit between
the socket and the mains plug of the pumps.
For retrospective installation, secure the float cable to the
pump, the riser tube or some other permanently installed
point in accordance with the desired switching distance
and switching level. In no event may the float with ca-
ble simply be thrown into the conveyed liquid, since
correct switching on and off is possible only when the
float rotates around the fastening point of the cable. Pos-
sible consequences of non-compliance include flooding
(pump does not switch on), or destruction of the pump by
running dry (pump does not switch off).
ON
OFF
Important: After any alteration of the float fastening, fault-
less operation of the float circuit is to be checked without
fail by means of a trial run.
Installing a check valve
In most applications, the pumps are used as emergency
pumps and are therefore only very seldom put into oper-
ation. The pump is therefore not fitted as standard with
a check valve. The reason for this is a possible functional
impairment of the pump under certain conditions. If a very
long time (months or years) has elapsed since the last
operation, dirt arising from the water column standing on
the check valve (the surface water extracted during the
last operation may have contained plenty) may have been
deposted on the check valve and prevent opening. This
applies in particular, since after a prolonged standstill the
pump must be completely vented for every initial start.
The disadvantage with an installation without check valve,
that the water running back from the piping with the other
residual water has to be taken up (mopped up or elim-
inated with a wet suction device), is therefore prefera-
ble in most cases to a possible failure of the pump in an
emergency. A check valve should therefore be assembled
only in applications with frequent operation (at least 1 x
weekly).

5.3. Bringing into service

This section contains all important instructions for operat-
ing staff to start up and operate the machine safely. The
following information must be complied with and checked
without fail:
• Type of installation
• Mode of operation
• Minimum water cover / max. immersion depth
These details are also to be checked after a prolonged
standstill period, and any defects discovered are to be
eliminated. The operating and maintenance manual
must always be kept at the machine, or in a place in-
tended for that purpose, where it is always accessible
to all operating staff.
In order to prevent damage to property or injury to per-
sons while starting up the machine, the following points
are absolutely to be complied with:
The commissioning of the machine may only be per-
formed by persons qualified for the purpose who com-
ply with the safety notes.
• All personnel who work on the machine must have
received, read and understood the operating instruc-
tions.
• Before commissioning, enable all safety devices and
emergency-off circuits.
• Electrotechnical and mechanical settings may only be
made by knowledgeable persons.
• This machine is suitable for use only under the stated
operating conditions.
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