Ier steamOvap, Installation And Operation Manual

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I N S T A L L A T I O N
Installation – step 6
Control installation
General guidelines for control installation
It is a good prac ce to install the following safety controls:

An air proving switch (model DAP) in the same duct as the humidifier’s steam ramp so that
it can prevent humidifier from producing steam in case there is no air flow.

A high limit humidistat (model DHL) shall be installed downstream of the steam ramp so
that it can prevent any over humidity (condensing) occurrence. High limit humidistat is
usually provided by an on-off switch its set point should be 85%RH minimum.
High limit humidistat should be placed at least at a distance equivalent to five mes the
absorp on distance. If the absorp on distance is not known, locate it at least 9 feet [3m]
downstream of the steam ramp.
For system that needs very accurate RH% control a RH% sensor can replace or supplement
the On/Off Hi Limit humidistat in this case the IER humidifier will not only modulate the
steam produc on based on the control; signal demand but also on this propor onal Hi-
Limit signal.

An enable dry contact can also be wired to switch the humidifier ON or OFF, this enable
contact can be used either as a third safety control or as a way to control the humidifier ON
and OFF, although IER steam humidifier is fully modula ng.
Room
supply
Outside Air
1
w
in
do
w
Outside
3
2
F
Steam ramp in
AHU or in duct
D = 5xNWD
or 9 [3m]
Duct Hi Limit RH%
Air Proving switch
Room RH% sensor
or humidistat
Best posi on is closed to returned air grill
return
Duct RH% sensor
Best posi on is in the return
Avoid placing Room RH% on an
exterior wall of closed to a window
It is not recommended to install
Room RH% next to air supply
rh
AHU or RTU
Figure 41, Controls placement recommenda ons
If Duct RH% sensor is used, it should be placed in return air duct
If Room RH% or humidistat is used, it should not be placed on an exterior wall, or next to
supply air grill. Best posi on is closed to returned air grill.
Air proving switch should not be placed next of a fan or a plate that can vibrate, this would
lead to wrong readings or early failure.
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