Xylem Sphere and Block Units - Manual (Page 12)

en
6.1.2 Differential switch protection
We recommend that a high sensitivity differential switch (30 mA) be installed as extra protection against lethal
electric shocks in the event of faulty grounding.
6.1.3 Connection
Make sure that the supply voltage corresponds to the voltage indicated on
the pump’s rating plate.
Connect the pump to the mains using a multiple-pole switch or other device that ensures multiple-pole
disconnection from the mains (interruption of all the supply wires except for the ground wire) with a contact
separation of at least 3 mm. All the single-phase pumps are equipped with a built-in automatic reset overload
protection, therefore no external protections are necessary. Remove the pressure switch cover by first loosing
the fastening screws. Carry out the connections as shown in fig. 2-3 (single-phase version).
6.1.4 Version with power cord and plug
For models fitted with power cord and plug, the pump must be installed in such a way that the plug and socket
are always accessible, in case it should be necessary to deactivate the pump.
If the power cord is damaged, call a customer service centre or qualified technician to have it replaced.
6.2 Priming
The pump must be filled with water before you start it. Dry running would
damage the mechanical seal and impeller.
Fill both the suction pipe and the pump body with water through the fill plug on the side of the delivery port.
Carry out this operation carefully to prevent formation of air pockets inside the suction pipe or the pump
body. Start the pump with the delivery on-off valve closed (fig. 1). After a few seconds check the pressure on
the gauge. If the pressure increases, let the pump run until the pressure switch stops it. If the pressure does
not increase stop the pump, re-prime it and then start it again. The pressure switch has been set at the
factory. The factory setting can be modified following the instructions of the pressure switch manufacturer. In
this case, adjust the air pre-loading inside the tank to a value of 20 kPa (= 0,2 bar) less than the new
minimum pressure setting.
Frost can damage the pump if it remains full and inactive at freezing
temperatures.
7. Maintenance
The pump does not require any regularly scheduled maintenance (see pump handbook).
All maintenance operations should be carried out by skilled and qualified personnel.
Make sure that the pump is disconnected from the power supply before carrying
out any maintenance operations.
You should check the air pre-loading at least once a year with the pump down and the system empty.
DANGER
RISK OF
ELECTRIC SHOCK
WARNING
WARNING
WARNING
12