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Operation
Probe system
Standard or softened water systems use conductivity probes to
measure and control water level for optimum operating efficiency.
Water conductivity must be at least 100 μS/cm for the probe
system to operate. The three-probe system is monitored by the
Vapor-logic4
board, which performs all the necessary logic and
timing functions to provide total water level control and safety
shutdown.
Vapor-logic4
automatically maintains the water level between the
upper two probes A and B (see figure on this page). When the
water level falls below probe B, the fill valve opens until the water
level reaches the upper probe A. Water must remain in contact
with the probe surface for three seconds for Vapor-logic4
to
determine that the water is at the probe’s level.
Conversely, water must stay out of contact with the probe surface
for three seconds for Vapor-logic4
to determine that the water
is below the probe’s level. This three-second delay ensures that
turbulence does not cause an incorrect level reading.
Each time the fill valve energizes, the Vapor-logic4
system tests
the probe system. If the signal from the probe assembly begins to
deteriorate, the “Clean probes” message appears in the Messages
Log. Once the probe system reaches its maximum usable life,
the humidifier shuts down and the “Faulty water probe” alarm
appears.
An adjustable skim time allows for an extended skim period
(0 to 120 seconds) to reduce mineral accumulation. When
skimming, the fill valve remains energized after the water level
reaches the upper probe, A, for the amount of time specified by
the skim duration. The skim duration is adjustable in one-second
intervals through the Setup menu.
Probe C provides low water protection for the heating outputs.
If the water level falls below probe C, the heating outputs are
disabled.
Systems using tap or softened water control
water levels electronically using a three-
rod probe. The controller responds with the
above actions when the water level reaches
each rod.
A: Fill valve closes
B: Fill valve opens
C: Low-water cutoff
Figure 51-1:
Water level control for standard
water systems
VLC-OM-030
W a t e r l e v e l c o n t r o l
