SUGGESTED ENGINEERING
SPECIFICATIONS
SD2000
ELECTRONIC STEAM HUMIDIFIERS
15781 HUMIDIFIERS
I.
GENERAL
A.
Scope
1.
Furnish and
install as indicated on the drawings and plans, in-duct [space] electronic
steam humidifiers.
2.
Furnish
owner's manuals and blueprints covering installation, start up, maintenance and
operating instructions, complete in every way to permit efficient operation and
maintenance of the system.
3.
Manufacturer
shall warrant the system to be free from defects in materials and workmanship
for a period of 2 years after the sale.
4.
Capacities are
as shown on the drawings and plans.
II.
PRODUCT
A.
Humidifiers
1.
The
humidifiers shall be of the self generating electrode type, electrically
producing atmospheric steam in a plastic cylinder without the use of immersion type electric heating elements.
2.
The humidifier
cabinet shall be constructed of 16 gauge steel, painted or coated inside and
out to protect against corrosion and to be aesthetically pleasing.
3.
The electrodes
shall be constructed of expanded low carbon steel, zinc plated and dynamically
formed for precise current control and cleanability.
Electrical connection to the electrodes shall be by screw down connectors.
Spark plug type connectors can loosen and are therefore unacceptable.
4.
The steam
generating cylinder shall be constructed of a UL listed plastic having at least
a 94HB safety rating, and being of a design to withstand cleaning by light
acids and reuse.
5.
The steam
generating cylinder shall have twin cylinder full electrodes operating as an
independent circuit from the main power electrodes. No artificial neutral
circuits shall be required. Additionally, the cylinder full electrodes shall be
used to detect foaming of the water.
6.
Units
producing over 30 lbs/hr capacity shall incorporate a power drain pump instead
of drain solenoid to provide for more efficient flushing of the cylinder.
7.
All internal
electrical controls and components shall be prewired
to appropriately marked terminals for field connection. All internal components
and the cabinet shall be properly grounded and shielded to prevent any line or radiative interference.
8.
The
humidifiers shall incorporate a true microprocessor control providing the
following functions:
a)
Automatic
flushing of the steam generating cylinder based on conductivity, not just
amperage draw, to extend the life of the electrodes. The humidifier shall read
AND display the incoming water conductivity.
b)
Pushbutton
selection of drainage under power or timed drain to eliminate current leakage
through the drain.
c)
Digital LCD
Display of:
Incoming
water conductivity
Electric
current draw in Amps
Output
of the humidifier
Selected
output limit
Model
No. and unit configuration
[Display
of sensed %RH on unit] [in CDH, CDD models]
[Display
of %RH setpoint] [in CDH,
CDD models]
[Display
of differential] [in CDH, CDD models]
9.
The humidifier
shall have the AFS anti-foaming system to allow automatic detection and
correction of water foaming. The humidifier shall be capable of operating on
water qualities ranging from 50-1500 micromhos
conductivity. Additionally, the AFS system must be capable of working on water
treated with phosphates. Softened water
should not be used.
10.
The humidifier
microprocessor control shall incorporate complete diagnostics, including the
following alarms and prealarms which shall be shown
on the LCD display:
High
electric current in the steam cylinder
Low
current electrolysis condition
Reduced
steam output, unable to reach setpoint
High
water level in cylinder
Humidity
sensor defective
Water
foaming in cylinder
Improper
cylinder fill rate
Improper
cylinder drain rate
Diagnostic
memory test fail
All
prealarms shall be self-correcting.
11.
The
humidifiers shall be configured for CDC-On/Off
[CDP-Proportional]
[CDH-Proportional
with humidity readout]
[CDD-Proportional with dehumidifier output] operation.
12.
Each
humidifier shall have a built in serial adapter connection allowing future
interface to computer or
13.
[Optional] The
humidifiers shall be provided with a direct [remote] mount Room Distribution
Unit for direct discharge of humidifying steam into the area to be humidified.
14.
[Optional] The
humidifiers shall be provided with a factory mounted condensate pump to pump
the drain water to an overhead or remote drain.
B.
Installation
1.
The
humidifiers shall be installed as per the plans and drawings, connected to a
potable cold water feed line, and a hot water drain line and electrical service
sized appropriately for the maximum current draw of the unit. All wiring shall
be in accordance with national and local electrical codes.
2.
Manufacturer
shall supply a duct mounted air flow proving device to prevent system operation
on loss of air flow.
3.
Manufacturer
shall supply a duct mounted high limit humidistat to prevent condensation in
the duct.
C.
General Operating Sequence And Control
1.
All humidity
sensors shall continuously send their signals to the control cabinet for
processing and indication.
2.
On a signal
indicating a requirement for humidity, the humidifier shall read the feed water
conductivity and initiate the diagnostic sequence. Upon completion, the
conductivity shall be entered into memory to control the cylinder flushing
cycle and the power contactor shall be energized. The fill valve shall be
activated as required to reach output and replenish water being boiled off or
drained.
3.
If the current
exceeds the maximum level, due to warming of the water in the steam generating
cylinder, the humidifier shall automatically drain to reduce the current to the
setpoint level.
4.
If the water
is of low conductivity, the humidifier will automatically annunciate a special
low conductivity startup algorithm which will concentrate the minerals to
permit output capacity to be reached sooner.
5.
If the
humidifier is operating on proportional control, it shall track with the
control signal, filling and draining as required to supply the humidity
requirements. Tracking with the signal shall be immediate, without delay.
6.
The humidifier
shall incorporate "adaptive intelligence" to prevent it from hunting
and reduce fluctuations to minimum automatically zeroing to the setpoint and maintaining precise chemistry control in the
steam generating cylinder.
7.
The humidifier
shall automatically control the cylinder chemistry to prevent premature plate
out of the minerals on the electrodes, and through precise chemical control
shall help to keep the drain lines clean. The unit shall indicate when the
cylinder is approaching the end of its useful life, but without shutting down.
III.
EXECUTION
A.
General
1.
Install the
humidifiers as detailed in the installation drawings and schedules and/or as
recommended by the manufacturer.
2.
Manufacturer
to furnish complete submittal drawings before installation and operating
manuals after.
3.
Humidifiers
shall be the DGH-Carel SD 2000 series electronic steam humidifiers as
manufactured and distributed by:
Carel
Ph: 717-664-0500
FAX:
717-664-0449
Form:
sdspec061604