Nortec ME Direct Feed - Manual (Page 17)

17 Product Overview
Functional description
As standard the Nortec ME Direct Feed is operated with On/Off control (requires a drain and a supply
valve fitted to the hydraulic manifold (both valves available as options) and a customer supplied On/Off
control or the optional direct feed On/Off control unit).
Equipped with the optional stage valves and the optional direct feed stage control unit, stage control
can be established.
In case of a humidification/cooling request with
standard On/Off control the drain solenoid valve (NO)
closes and the inlet solenoid valve (NC) opens and the water flows to the distribution header above the
evaporative cassettes.
In case of a humidification/cooling request with
optional stage control unit the drain solenoid valve (NO)
closes and the inlet solenoid valve (NC) opens. Depending on the demand signal and the evaporative
module size additionally stage valve two, three, four and five open to supply water to the distribution
header of the corresponding evaporative cassettes bank.
The distribution pipes inside the distribution header evenly supply the water to the entire surface of the
evaporative cassettes where it flows down and humidifies the air flowing through the evaporative cassette
matrix. The excess water not used for humidification flows to the water tank and then directly to the drain.
Both optional direct feed control units (On/Off control unit and stage control unit) support time based
flushing of the water supply line once a purge valve (available as option) is fitted in the supply line. Every
20 hours the water supply line is flushed via the purge valve to prevent water stagnation in the water
supply line which can lead to the grow of micro-organisms in the water supply line.