Danfoss VLT 7000 Series, Руководство пользователя

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VLT® 7000 Booster
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Fixed lead pump control (mode 1-8)
When choosing this control type, the VLT will be fixed
to one pump (pump no. 1) - the lead pump, and the
remaining pumps (the lag pumps) will be operated
ON/OFF. Up to 7 pumps can be connected.
Mode 1-4
Mode 5-8
P1, P2, P3,... are the pump numbers, that can also
be seen in the display of the VLT. R71, R72,.... are
the relays switching on and off the different pumps.
Please notice that the relay numbers are not unique,
as some of the terminals on the VLT 7000 Cascade
Controller Card have the same numbers. The relay
numbers are only used to describe the functionality
in the manual. The relay numbers are not used in
the display or in the wiring diagrams.
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Alternating lead pump control (Mode 9-14)
This control type makes it possible to circle the VLT
between all the pumps in the system. Whenever
more pump capacity is needed, the VLT will switch
the lead pump to mains, and start up a new
pump. Consequently there will not be a fixed
lead pump in this control type.
Mode 9-10
Mode 11-12
Mode 13-14
As to pumps and relays, the same applies
as described above.
Please observe: If the pressure demand never exceeds
one pumps capacity, there will no changing of the lead
pump, as this only happens during staging.
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AUX pump
At low flow demand, it can be an advantage to
switch on a small pump, instead of running the
lead pump at low speed. This pump is called an
auxiliary pump (AUX pump). As can be seen in the
scheme above, the AUX pump can be controlled
by a relay on the cascade controller card (Relay
R78) or by the control card relay (CCR).
MG.70.A1.02 - VLT is a registered Danfoss trademark
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