Fläkt Woods
3176 GB 05.08
4
Specifications are subject to alteration without notice
EU Air Handling Unit
MAINTENANCE
EUQA Humidifier, for circulated water
To set the timer for emptying and flushing
For normal function, the timer should be preset to
"ON". When emptying, which can be programmed to
occur once or several (optional) times every 24-hour peri-
od, the timer will reset itself to the "OFF" setting for 10
minutes. After that, the timer will reset itself to "ON" for
2 minutes to allow flushing.
The timer will then reset itself to the "OFF" setting for
3 minutes for additional emptying before resetting itself
back to "ON" for normal operation.
In the following example, emptying and flushing are
required once every 24 hours from 12.00 to 12.15 as
scheduled below.
Periods
Timer setting
Activity
00.00–12.00
ON
Normal operation
12.00–12.10
OFF
Emptying
12.10–12.12
ON
Flushing
12.12–12.15
OFF
Additional emptying
12.15–24.00
ON
Normal operation
This can be done most easily by programming the opera-
tion times from 12.15 to 12.00 and from 12.10 to 12.12
on a daily basis! Emptying and additional emptying will
then occur from 12.00 to 12.10 and from 12.12 to 12.15
respectively.
Water quality
Evaporation causes an increase in the concentration of
minerals in the circulating water, which necessitates
continuous bleed-off and make-up with fresh water.
The bleed-off rate is dependent on factors such as:
■
the pH of the water
■
the bicarbonate concentration (HCO
3
), mg/l
■
the calcium concentration (Ca
2+
), mg/l
This data can be obtained from a municipal water autho-
rity or by analysing the water.
Lime precipitation can be prevented by plotting the per-
tinent data in Chart 1 on page 4 to determine the current
risk zone. Water level monitor B can then be set accor-
ding to the relevant zone. If the water is too hard, it may
be necessary to subject it to partial softening.
In addition to the risk of lime precipitation, the concent-
ration of chlorine (Cl) and copper (Cu) must be taken
into account. To ensure acceptable performance, the con-
centration of Cl in the fresh water must not exceed 50
mg/l and that of Cu must not exceed 0.02 mg/l.
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