Page 1
READ AND SAVE THESE INSTRUCTIONS
ELECTRONICALLY CONTROLLED STEAM HUMIDIFIER
DESIGN SERIES F
INSTALLATION, OPERATION
AND MAINTENANCE MANUAL
CARNES COMPANY, 448 S. Main St., P. O. Box 930040, Verona, WI 53593-0040 - Phone:608/845-6411- Fax:608/845-6470 [email protected] http://www.carnes.com
External Disconnect
or Circuit Breaker
(Not Provided by Carnes)
Water Shutoff Valve
(Not Provided by Carnes)
Steam Output
Rate Meter
“Abnormal”
Lamp
Steam Output
Control
On-Off-Drain
Switch
Optional
Circuit
Breakers
Power
Contactors
Brass Cylinder
Fittings
Drain Solenoid
Valve
Cylinder
Retaining
Band
Steam
Cylinder
Terminal
Connectors
Overflow
Sensor
Steam Hose
“On” Lamp
Door
Interlock
Make-Up
Solenoid
Valve
Photo A
(Model HBHF Shown)
FORM 16713
ISSUED: 12-95
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INSTALLATION
UNPACKING AND INSPECTION
1. An envelope attached to the outside of the cabinet
contains one cabinet key.
2. Open the cabinet and check for concealed shipping
damage. Repor t any damage immediately to the
carrier who delivered the shipment.
3. The following components are packed in a shipping
carton for connection when installing humidifier.
A. Distribution pipe.
B. Steam hose.
C. Condensate return line.
4. Optional accessories may be packed with the cabinet
or in the same shipping carton. Large accessories
may ship in separate cartons.
5. Inside the cabinet is an envelope containing the
following items:
A. Steam hose clamps.
B. Condensate return line clamps.
C. Air gap drain fitting.
D. Installation instructions.
MOUNTING THE HUMIDIFIER
Mount the humidifier cabinet securely on a level and plumb
surface near the ductwork. Allow 6” or more on each side
for proper ventilation and minimum of 16”from the bottom of
the cabinet to the floor to allow space for the drain connection. The humidifier must never be mounted outside or
where it may be exposed to freezing temperatures.
Maximum operating weights for the humidifier are shown
below.
Table 1 -
MAXIMUM OPERATING WEIGHT
WATER SUPPLY CONNECTION
Use ordinary tap water (20 to 120 psi) - DO NOT use hot
water, deionized water, or water that has been treated
by a water softener without consulting the factory. A
3/8” FPT fitting is provided at the top of the humidifier for
connection to tap water supply. A shutoff valve, not provided by Carnes, must be installed just ahead of this fitting.
DRAIN LINE CONNECTION
1. Remove the large nut and plastic gasket located on
the fitting on the bottom of the cabinet.
(Photo B)
.The
nut and gasket may be used with standard type drain
fitting if an air gap fitting is not required by local
codes.
2. Connect the air gap drain fitting to the cabinet drain
connection. It may be necessary to cut off some of
the air gap fitting depending on available space.
3. Connect the drain or air gap fitting to S or P trap.Use
plumbing material capable of handling hot water.
Note:
If the drain water pump accessory package is
used, follow instructions included with the drain water
pump package.
Model Pounds
HBAF, HCAF 80
HBDF, HCDF 85
HBGF, HCGF 105
HBHF, HCHF 185
Drain Line
Connection
Photo B
6 FASTENERS REQUIRED (Models HBAF, HCAF, HBDF, HCDF)
TYPE OF WALL 8 FASTENERS REQUIRED (All Other Models)
Wood Studs or Solid Wood 1/4” Lag Screw, 1” Minimum Length
Hollow Plaster 1/4” Molly Bolts or Toggle Bolts, 3” Minimum Length
Sheet Metal 1/4” Thread Forming Screws, 1/2” Minimum Length
Cement or Masonry 1/4” Lead Type Anchor and Bolts, 1-1/2” Minimum Length
Table 2 -
FASTENER RECOMMENDATION
Page 3
STEAM DISTRIBUTOR PIPE LOCATION
Each steam cylinder in two-cylinder units require a separate
steam distributor pipe, steam hose, and condensate return
line.
In a typical installation, the humidifier is located below the
duct as shown in
Figure A
. It is recommended that the
length between the humidifier cabinet and the steam distributor pipe in the duct be the minimum possible distance.
Refer to
Table 3
for maximum lengths that may be installed.
Figure A
The maximum length of steam hose that may be installed as
shown in
Figure A
is 12 feet. For a steam hose length over
12 feet refer to
Figure B
.
A drain “T”, as shown in Figure B, must be used to remove
condensation that occurs in steam hose lengths over 12
feet. It is preferable to have the steam hose rise vertically
from the cabinet and the slope toward the distributor pipe as
shown. If sufficient head room is not available, it is possible
to install with an upward slope to the hose.
Figure B
If airflow is vertical, the steam distributor pipe should be
installed horizontally
(Figure C)
.
In two-cylinder units the pipes should be staggered as
shown
(Figure D)
.
Figure C
Figure D
MAXIMUM STEAM HOSE LENGTH
(Table 3)
Duct Static
Pressure “wg”
012345
Maximum Steam
Hose Length (Ft.)
40 35 30 25 15 10
3
Page 4
STEAM DISTRIBUTOR PIPE LOCATION (Continued)
Steam distributor pipes must be located on a plumb surface.
This is required so the condensate which forms in the distributor pipe will drain to the return line and back to the unit.
Steam distributor pipes should be mounted in the duct to
insure even distribution of steam across the center portion
of the duct.The condensate return line must alwa ys be kept
on the bottom. A minimum clearance of 4” must be maintained between top of the duct and distributor pipe.
The steam distributor pipe should be located in the supply
air stream, downstream of the fan.When installed in packaged units (central station air handlers, multizone units,
make-up air units, etc.) the distributor pipe should be
mounted just downstream of the fan discharge in the primary air stream.
In multizone applications it is preferable to have a separate
humidifier serving each zone. However, steam can be introduced into the hot deck upstream of the zone dampers. In
this case, good distribution of steam across the entire hot
deck is very important.
The steam distributor pipe may be located below the humidifier if the installation is made in accordance with
Figure E
.
A trap must be installed as shown to prevent steam from
flowing back through the condensate return line.
Figure E
It is preferable to locate the steam distributor pipes downstream from any obstructions in the ductwork so that air can
absorb moisture before it impinges on a surface and accumulates. There must be a minimum of six feet between the
steam distributor pipes and any fans, coils, filters, zone
dampers, elbows or outlets which may be installed downstream of the distributor pipe. However, in all cases, the
steam distributor pipes should be located as far upstream
from any such obstruction as possible.
It is very important that the steam hose is installed so that
sags in the hose are prevented. Because the steam is at
very low pressure it cannot overcome resistance caused by
water standing in the steam hose.The steam hose is flexible so it must be supported adequately to prevent any low
point from occurring. The steam hose and condensate
return line must have a continuous pitch so that standing
water will not develop.
If it is difficult to install the steam hose to prevent sags, it is
recommended that copper tube be used as a substitute. If
copper tube is used, a minimum of one inch of insulation
must be applied to prevent excess condensation. A shor t
length of steam hose should be used to connect to the cylinder in the humidifier and another short length to connect to
the steam distributor pipe. Size 3/4” copper tube should be
used with steam cylinders having output rates up to 30
pounds of steam per hour. Size 1-1/2” copper tube should
be used with steam cylinders over 30 pounds per hour. The
condensate return line which connects the outlet on the
steam distributor pipe to the inlet on the top of the humidifier also must be supported to prevent sags that would
restrict the flow of water.
INSTALL STEAM DISTRIBUTOR PIPE
EACH CYLINDER REQUIRES SEPARATE STEAM HOSE,
CONDENSATE RETURN LINE, AND STEAM DISTRIBUTOR PIPE.
1. Steam distributor pipe must be mounted on a plumb
surface.When on a plumb surface the standard
distributor pipe is inclined upward.This is required so
the condensate which forms in the distributor pipe
will drain to the return line and back to the unit.
2. Inser t distributor pipe into duct and secure with four
sheet metal screws, not provided by Carnes.
3. Special distributor pipes are shipped with specific
instructions on how to mount them.
4. If the optional fan distribution unit is to be used,
follow the instructions included with the unit.
CONNECT THE STEAM HOSE
COPPER OR BRASS TUBE IS THE ONLY ACCEPTABLE
SUBSTITUTE FOR CARNES STEAM HOSE OR CONDENSATE HOSE.
1. The steam hose should be installed so there is a
continuous rise from the humidifier to the distributor
pipe. Suppor t the steam hose at inter mediate points
to prevent dips or pockets.
2. Any turns should have a minimum radius of 8” to
prevent the hose from kinking.
3. Fasten the steam hose to the distributor pipe with one
of the hose clamps provided.
4. Push the steam hose through the opening on the top
of the humidifier cabinet and slip over the outlet stub
on the top of the cylinder.Fasten the hose clamp
provided.
CONDENSATE RETURN LINE
1. Fasten the condensate return line to the distributor
pipe with the hose clamp provided.
2. Follow the steam hose to the humidifier cabinet and
secure the return line to the steam hose.
3. Connect the return line to the condensate retur n inlet
with hose clamp provided.
4. If it is impossible to maintain a drop to the top of the
cabinet, it is necessary to run the condensate retur n
line directly to the air gap drain fitting or some other
drain.
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ELECTRICAL DATA
Table 4
Opt.
Max. Line Disc. Circuit Steam
Model Lb/Hr. K.W. Ph. Volt Amp Size Breaker Cylinder
120 14.4 20 1-20 1-AX220
208 8.3 15 1-15 1-AX380
5 1.7 1 230 7.5 15 1-15 1-AX380
277 6.2 15 1-15 1-AX380
460 3.7 15 1-15 1-AX700
575 3.0 15 1-15 1-AX700
HCAF 120 28.7 40 1-40 1-AX220
208 16.6 25 1-25 1-AX380
10 3.4 1 230 15.0 20 1-20 1-AX380
277 12.4 20 1-20 1-AX380
460 7.5 15 1-15 1-AX700
575 6.0 15 1-15 1-AX700
208 33.1 45 1-45 1-B500
230 29.9 40 1-40 1-B500
20 6.9 1 277 24.9 35 1-35 1-B500
460 15.0 20 1-20 1-B700
575 12.0 15 1-15 1-B700
208 19.1 25 1-25 1-B500
230 17.3 25 1-25 1-B500
HCDF 20 6.9 3 460 8.6 15 1-15 1-B700
575 6.9 15 1-15 1-B700
208 28.7 40 1-40 1-B500
230 25.9 35 1-35 1-B500
30 10.3 3 460 13.0 20 1-20 1-B700
575 10.4 15 1-15 1-B700
208 49.7 70 2-35 1-C62
230 44.9 60 2-30 1-C62
30 10.3 1 277 37.3 50 2-25 1-C62
460 22.5 30 1-30 1-C65
575 18.0 25 1-25 1-C65
208 38.2 50 2-25 1-C62
230 34.6 45 2-25 1-C62
40 13.8 3 460 17.3 25 1-25 1-C65
575 13.8 20 1-20 1-C65
208 47.8 70 2-35 1-C62
230 43.2 60 2-30 1-C62
HCGF 50 17.2 3 460 21.6 30 1-30 1-C65
575 17.3 25 1-25 1-C65
208 57.4 80 2-40 1-C62
230 51.9 70 2-35 1-C62
60 20.7 3 460 25.9 35 1-35 1-C65
575 20.8 30 1-30 1-C65
208 76.5 100 2-50 1-C62
230 69.2 90 2-50 1-C62
80 27.5 3 460 34.6 50 2-25 1-C12
575 27.7 40 2-15 1-C12
208 95.6 125 2-60 1-C62
230 86.4 125 2-60 1-C62
100 34.4 3 460 43.2 60 2-25 1-C12
575 34.6 45 2-20 1-C12
208 119.5 175 4-40 2-C62
230 108.0 150 4-35 2-C62
125 43.0 3 460 54.0 75 4-20 2-C12
575 43.2 60 4-20 2-C12
208 143.4 200 4-60 2-C62
230 129.7 200 4-50 2-C62
150 51.7 3 460 64.8 90 4-25 2-C12
HCHF 575 51.9 75 4-20 2-C12
208 167.3 250 4-60 2-C62
230 151.3 225 4-50 2-C62
175 60.3 3 460 75.6 110 4-25 2-C12
575 60.5 90 4-20 2-C12
208 191.2 300 4-60 2-C62
230 172.9 250 4-60 2-C62
200 68.9 3 460 86.4 125 4-35 2-C12
575 69.2 100 4-25 2-C12
NOTES:
“Model”and “Opt. Circuit Breaker” columns
designate presence, quantity and amp rating
of optional circuit breakers.All models preceded by“HC” have overload protection provided
by the electronic circuit board. In addition, as
an option, internally mounted, switchable onoff, circuit breakers are available in models
preceded by “HB
”.
“Max Lb./Hr.” designates maximum capacity
of humidifier.Units are shipped from the factory preset at the maximum rate.The output rate
may be easily reset after installation anywhere
between 100% and 25% of maximum capacity.
“KW” ratings shown is at maximum output
rate. If a unit is reset for less than maximum
output, the KW is reduced proportionally.
“PH ” and “Volt” designate available phase
and nominal voltages.Single phase units may
be operated from two legs of a three phase
supply but the load will be unbalanced.
“Line Amp” and “Disc. Size” are amp ratings
shown for use in selecting electrical service
requirements.
“Steam Cylinder” columns shows the quantity and the model of steam generating cylinders mounted in the humidifier. Each cylinder
requires its own steam distribution pipe, steam
hose and condensate return line.
ELECTRICAL CONNECTIONS
POWER MUST BE OFF BEFORE MAKING
ANY ELECTRICAL CONNECTIONS
Check unit electrical characteristics on label
outside of cabinet. It must agree with power
provided to the unit.If it does not, contact your
Carnes Representative.
A fused disconnect or circuit breaker not provided by Carnes, MUST be installed per local
and national codes. See
Table 4
for recommended circuit ratings. The optional circuit
breaker switch in the humidifier is NOT for use
as a disconnect switch.
1. Remove screws securing lower electrical
cover panel for access to wiring.
2. An opening is provided on the bottom of
the electrical section. Bring electrical
power lines through this opening and
connect to electric power terminals.
3. Connect cabinet ground terminal to an
independent ground. DO NOT use the
neutral of a four-wire power supply.
4. Replace electrical cover panel.
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CONTROLS
CONTROL OPTIONS - Figure F
CONTROL HUMIDISTAT AIR FLOW DETECTION CONDENSATION
PROTECTION
WALL HUMIDISTAT
PROPORTIONAL
CONTROL
CARNES MODEL HXHBG
OR
WALL HUMIDISTAT
ON-OFF
CONTROL
CARNES MODEL HXHAA
OR
DUCT HUMIDISTAT
PROPORTIONAL
CONTROL
CARNES MODEL HXHBH
OR
PRESSURE
DIFFERENTIAL
SWITCH
CARNES MODEL HXAAE
OR
DUCT HUMIDISTAT
ON-OFF
CONTROL
CARNES MODEL HXHAB
DUCT HUMIDISTAT
WITH
AIR FLOW SWITCH
CARNES MODEL HXHAC
AIR
FLOW
SWITCH
CARNES MODEL HXAAF
HIGH
LIMIT
HUMIDISTAT
CARNES MODEL HXHAD
OR
CONTROL HUMIDISTAT
If an on-off humidistat is used the humidifier will generate
steam at the preset output rate and cycle on or off as necessary to satisfy the conditioned area requirements. All
humidifiers are preset at the factory for the maximum rating
of the unit. The output may be easily reset in the range of
25-100% by adjusting the control located on the front of the
electronic control module.
If Carnes proportional humidistat is used the humidifier will
automatically vary the steam output rate in the range of 25100% of the humidifiers maximum rating in response to the
signal from the humidistat. The steam output control mentioned above ma y also be used to limit the maximum output
desired. Proportional control provides less cycling of the
humidifier.
Either a wall humidistat or duct mounted humidistat in the
return air may be used.The wall mounted humidistat is the
most common as it allows the setting to be easily changed
to accommodate changing requirements or to lower the relative humidity in the space to prevent condensation on windows during extremely cold weather. In applications where
it may be desirable to prevent the occupants of a space
from changing the setting, a duct mounted humidistat in the
return may be used.This is normally mounted in the equipment room or in the duct where it is accessible only to maintenance personnel.
AIR FLOW DETECTION
The humidifier control circuit should include some method
to determine air flow. If the steam distributor pipe is located
in a duct where there is no air flow and the control humidistat is calling for humidity, steam would be discharged into
the duct where it would immediately condense.Air flow may
be detected by several methods.The humidistat circuit may
be interlocked by using a fan relay if the fan is direct driven.
A fan relay is not recommended if a belt driven fan is used
as a broken belt would stop air flow even though the fan
relay was closed.
Among the alternatives are the use of a pressure differential switch that determines air flow by sensing a pressure
differential caused by air movement in the duct. A paddle
type switch is also available to determine air flow .The pressure differential switch is normally the preferred device as it
is less susceptible to erratic operation caused by improper
positioning in the duct system. Paddle switches require
careful positioning in the duct to insure sufficient air flow to
activate the switch. A combination return air duct on-off
humidistat and sail switch is available but care must be
taken during installation to insure proper operation.
Page 7
CCOONNTTRROOLLSS
CONDENSATION PROTECTION
A third device may be desirable to provide condensation
protection in the duct system.A high limit humidistat may be
installed ten feet downstream from the steam distributor
pipe. This humidistat is normally set to 90-95% RH and
opens the circuit if the humidity level in the duct e xceeds the
set point. Use of this device is recommended particularly
when the humidifier is used in applications where cooling
air is being humidified or where a VAV system may throttle
back to a point where air flow is insufficient to absorb the
steam being introduced.
CONTROL CONNECTIONS
FIELD WIRING TERMINAL BOARD
Figure G
A 12 volt DC signal is supplied to terminals 10 and 12
whenever the humidifier is operating and is used to activate
an electronic relay to start the fan motor in Carnes optional
fan distribution unit.Maximum current av ailab le at terminals
10 and 12 is 25 mA.
EXTERNAL CONTROL SIGNALS
Carnes humidifiers can also accept a 0-10 volt DC signal to
modulate the output of the humidifier.Selection of this type
of signal is made by switch S2 on the humidifier circuit
board. In the standard position any on-off humidistat can
be used. In the alternate position, signified by “V” in the
humidifier model number, a 0-10 volt DC signal may be
supplied to terminals 11 and 13. Polarity must be observed
and terminal 11 is a chassis ground. Input impedance is
100K ohms. The position of switch S2 may be easily
changed anytime if a change in control systems is desired.
Recalibration for input voltages other than 0-10 volt is possible. Consult the factory for ranges and calibration procedure. If a 4-20 mA. input signal is provided to the humidifier
a 470 ohm resistor must be installed across terminals 11
and 13.
HUMIDIFIER CIRCUIT BOARD
Figure H
An on-off humidistat is connected to terminals 11 and 13 on
the field wiring terminal board.The (+) and (-) markings are
not significant unless a signal is being supplied by an external humidity transmitter. The air flow detection control
should be connected to terminals 1 and 2. If a high limit
humidistat is used it should be connected to terminals 3
and 5. If it is not used a jumper must be installed.
A 24 volt AC signal is provided by the humidifier circuit
board to terminals 4 and 6 to indicate the need for service.
This signal is provided whenever the output is less than
50% of the desired rate. Maximum current available at terminals 4 and 6 is 1/2 Amp. It is not necessary to connect
any device to these terminals but a jumper must never be
connected.
S2
IMPORTANT:
TURN OFF POWER AT EXTERNAL DISCONNECT BEFORE MAKING ANY CONNECTIONS TO
PREVENT POSSIBLE DAMAGE TO ELECTRONIC CIRCUIT BOARD.
1. A 7/8”opening is provided on the top of the cabinet.
The control wiring should pass through the opening to
the terminal strip (Figure G).
NOTE:
A built-in transformer provides power for the
control circuit. No outside power supply is required for
the control circuit.
2. If an air flow switch or high limit humidistat is not used
jumpers must be installed before the humidifier will
operate.
CONTROL CONNECTIONS
Page 8
OPERATION
Figure I
STEAM
DISTRIBUTOR
PIPE
STEAM
HOSE
MAKE-UP WATER
SOLENOID V ALVE
AIR GAP
STAND
PIPE
OVERFLOW
SENSOR
TO DRAIN
VERTICAL
ELECTRODES
DRAIN
SOLENOID
VALVE
STEAM
WATER
CYLINDER
FROM POWER
CONTACTOR
Carnes state of the art electronic circuit board controls all
functions within the humidifier to provide the highest energy efficiency available. The circuit board is mounted in a
control module containing a steam output meter calibrated
directly in pounds per hour, an “on” light, and “abnormal”
operation light that indicates the need for maintenance.
Upon a signal from an external humidistat the circuit board
opens a make-up water solenoid valve, allowing water to
flow across an air gap into a standpipe.The standpipe provides a column of water to be fed into the cylinder using
gravity.The air gap prevents back flow into the water supply
and prevents the cylinder from becoming a pressure v essel.
The steam cylinder operates at a pressure of approximately 1/2 psi.
The circuit board also closes a power contactor allowing
current to flow to vertical electrodes sealed inside the cylinder.Current flows between the electrodes using minerals in
the water as a conductor.The water is heated to boiling and
converted to steam which leaves the cylinder through the
flexible steam hose which is connected to the steam distributor pipe.
The circuit board reacts to current flow between the electrodes and automatically opens the make-up solenoid valve
when more water is required to maintain the desired output
rate, and closes when the desired rate is reached. The
operation of the drain solenoid valve is automatically controlled by the circuit board which responds to any changes
in water conditions and drains the required quantity of water
to provide stable operation and long cylinder life.
Current flow in each leg of a three phase circuit is monitored
and in the event of overcurrent the contactor is opened to
disconnect power to the cylinder. The drain solenoid is
opened automatically to reduce water and current levels
and the humidifier resets for normal operation.If current levels are not reduced to normal levels the circuit board opens
the contactor and indicates the over-current condition by
flashing the abnormal light.
As mineral deposits build up within the cylinder the water
level will slowly rise to uncovered electrode surfaces to
maintain the desired steam output rate. When mineral
deposits have cov ered all a vailab le electrode surf ace areas,
current flow will be reduced to a level where the desired
steam output cannot be reached and the abnormal light will
signal the need for maintenance.When the cylinder is filled
with minerals it is easily changed in less than five minutes.
***
* * * *
***
* * * *
* * *
* * * *
*
*
*
*
*
*
Page 9
START UP
While the external disconnect switch is off, be sure terminal
connectors are firmly secured to the top of the cylinder.
1. Open all water supply valves exter nal to unit.
2. Turn external disconnect switch to “ON” position.
3. In units with optional circuit breakers, turn circuit
breaker(s) to “ON” position.
4. For safety, door interlock disconnects power to
cylinder(s) when door is open. Humidifier may be
operated for service purposes when door is open
by pulling out white button located above the meter.
CAUTION:
High Voltages Are Present.
5. Turn “On-Off-Drain” switch to “ON” position. Green
“ON” light should now be on.
6. Unit will now be in operation if humidistat is calling for
humidity. If Humidistat is not calling for humidity,
adjust humidistat control upward to check operation.
7. When humidistat is calling for humidity, water will
slowly flow into cylinder. Steam output meter will
slowly rise as water enters cylinder.
8. The “ABNORMAL” light will remain on until sufficient
water has entered cylinder to provide 50% of set
output. NOTE:
Unit has been preset at factory for
maximum output as shown on label on bottom left
side of humidifier.
9. When high level or full output is reached, the fill
solenoid valve will close.
NOTE:
When starting unit with new cylinder, the
“Abnormal” light may come on and the drain solenoid
valve and contactor may open for brief periods until
water has come to full boil.
LOW CONDUCTIVITY OPERATION
In areas where water conductivity is low, full output may not
be reached until humidifier has conditioned water.
1. If water comes in contact with the overflow sensor,
the fill valve will automatically close.
2. Water will boil and the fill solenoid valve will reopen.
3. Process will continue to occur until sufficient minerals
have accumulated to allow full output.
AUTOMATIC DRAIN CYCLE
The electronic circuit board controls the drain solenoid valve
to drain a portion of water from the steam cylinder.
1. As water boils away in the cylinder, a timer (indicated
by “BD “ lighted) is activated as current falls to 95% of
setpoint.
2. The timer runs for a predetermined time until 90% of
setpoint is reached.
3. If rate of change of current occurs too rapidly, the drain
solenoid will open to drain mineral rich water from the
cylinder.
4. Fill valve will automatically reopen to refill cylinder to
proper current level.
ADJUSTING STEAM OUTPUT RATE
Steam output is regulated by adjusting steam output control
(Photo C).
To change steam output:
1. Drain water from cylinder by turning “On-Off-Drain”
switch to “Drain”position.
2. Turn steam output rate control fully clockwise.
3. Turn “On-Off-Drain” switch to “On” position. Steam
output rate will gradually increase as shown on
steam output rate meter.When desired output is
reached, slowly turn counter clockwise until inlet
water valve closes and stops incoming water.
Steam Output Control
Photo C
ELECTRONICALLY
CONTROLLED
STEAM
HUMIDFIER
BD
HS
HP
SL
ON
ABNORMAL
ON OFF DRAIN
CARNES COMPANY
Verona, Wisconsin 53593
STEAM OUTPUT METER
TOP SCALE: HBGHCG
HBH/HCH
MIDDLE SCALE: HBD/HCD
BOTTOM SCALE: HBA/HCA
Page 10
TROUBLE SHOOTING
SYMPTOM:Water In Duct
POSSIBLE SOLUTIONS:
This is usually an installation
problem. First step is to determine if water is spitting from
the steam distributor pipe or if steam is condensing on
some object in the duct or on the duct itself.
If water is spitting from the steam distributor pipe there may
be several causes:
1. The hose and condensate retur n lines MUST have
continuous slopes without ANY sags or pockets that
could accumulate water. If water accumulates in the
steam hose, it may suddenly be pushed into the
distributor pipe and the condensate return line may be
unable to handle the large volume.
2. Make sure the condensate return line is not obstr ucted
in any way.Water should flow freely, through the return
line.
3. The mounting plate on the steam distributor pipe must
be plumb on the duct to obtain the proper pitch on the
portion inside the duct. If the portion inside the duct is
tilted downward condensate cannot flow away from the
duct.
4. If the condensate retur n line has a very small pitch
down from the distributor pipe to the humidifier cabinet,
(less than 1 foot) it may be better to go to a drain
below the cabinet rather than connecting at the top of
the cabinet.
If the water is condensing on an object in the duct or on the
duct itself, it will be necessary to take other steps:
1. The distributor pipe must be mounted AT LEAST 6 feet
from any elbow, split, coil, tur ning vane, grille or diffuser.The lower the air temperature is in the duct the
further upstream the pipe must be located. If the air
temperature is 55Oit may be necessary to have 10
feet between the pipe and any obstruction.
2. It may be that the air simply can’t hold the volume of
steam that is being introduced into it. Nor mally the only
practical solution is to reduce the steam output of the
humidifier as it usually not feasible to increase the air
temperature or quantity.
SYMPTOM:“Arcing” or “Sparking” In Steam Cylinder
POSSIBLE SOLUTIONS:
An occasional arc is not a problem.When a cylinder is restarted after a per iod of time arcing may occur as chunks of mineral flake of the electrode
surface. During a drain cycle arcing may occur if water is
very low in the cylinder. Arcing is a problem if it occurs
almost constantly and causes dark discoloration in the
cylinder
MANY ITEMS CAN CAUSE ARCING
1.
Incoming water high with conductivity.
Conductivity, the ability to conduct current, is measured
in “micromhos”. In any electrode type humidifier there
are maximum values of conductivity that may be used
in the humidifier.Maximum conductivities are shown in
Carnes Catalog HB-02.
If the water has been treated by a water softener, it’s
conductivity will be higher than if it is untreated. Soft
water may be too high in conductivity to operate without arcing.
2.
Build up of conductivity of water inside cylinder.
Arcing can occur if incoming water conductivity is
acceptable but other problems allow the conductivity
inside the cylinder to increase beyond its design
capabilities. This may be caused by:
A. Drain lines that have become restricted by mineral
deposits prevent proper drain rates.This allows minerals to concentrate inside the cylinder which causes low
water levels and therefore arcing. Drain lines should
be inspected when cylinders are changed and
thoroughly cleaned if necessary.
B. A defective solenoid valve will prevent proper draining. Disassemble and clean. The solenoid coil should
be checked to verify its condition.If the “drain” switch
is placed in the drain position both the fill solenoid and
drain valves should open.
C. A defective component or wiring harness may prevent the solenoid from operating.If the drain valve
operates in the manual drain position the wiring
harness is good but the circuit board may be defective. If the drain valve won’t operate in the drain
position either the valve or wiring harness may be at
fault. Check crimped on connectors for good connections.The best method to check the circuit board is to
substitute a board known to be good.
D. Insufficient quantity of incoming water will cause
arcing by causing low water levels. In electronically
controlled units a drain is never initiated until a setpoint is reached.Therefore, if low water pressure at the
unit (Below 20 PSI) or a clogged water strainer restricts the flow of water, arcing will result.High backpressure caused by an obstruction in the steam hose,
or excessive duct static pressure will also prevent the
cylinder from reaching its setpoint and initiating a
drain.
E. Frequent cleaning of the cylinder can dislodge flakes
that will cause blockage and prevent draining.It is not
recommended that the cylinder be removed except for
replacement.
Page 11
SYMPTOM: Drains Continuously
POSSIBLE SOLUTIONS:
The first step is to determine
whether water is overflowing from the fill cup or flowing
through the drain solenoid valve. It’s important to check
closely since both conditions appear identical but have
much different causes.
1. The most common cause is to have a piece of
sediment in the drain solenoid valve that prevents the
valve from closing properly. By turning the unit back
and forth between “ON” and “DRAIN” it may be
possible to dislodge the sediment. In extreme cases
it may be necessary to disassemble drain lines to
clean them.
2. If dirt in the valve is not causing the problem, disconnect one of the wires connected to the solenoid
coil. If draining stops this indicates the circuit board
is causing the valve to operate.The circuit board is
defective if it is sending an improper signal to drain
and should be replaced.
3. If water continues to drain with the wire to the solenoid
disconnected the valve is defective and should be
cleaned or replaced.
4. If water is flowing to the drain from the overflow tube
coming from the fill cup it is usually caused by an
obstruction in the water line between the fill cup and
cylinder or in the steam hose from the cylinder to the
steam distributor pipe. All lines and steam hoses
should be checked to eliminate any obstructions.
SYMPTOM: Humidifier Won’t Turn On
I. Ver ify Power is supplied to unit.
A.Verify green “on” light is lit.
1. If no light check
- Incoming high voltage and circuit breaker
- 24 VAC on secondary of power transformer
- Fuse (F2) on control module
a. Secondary options
- Lamp burned out
- Miswire or bad connection in module harness
- Harness not plugged into board properly
- Bad ON-OFF switch
- Defective control board
B. Verify (HS) LED is lit
1. If no LED, check
- High limit humidistat can be jumpered
- Air flow switch can be jumpered
- Humidistat can be jumpered
- Fuse (F1) on control module
TROUBLESHOOTING
- (S2) switch in wrong position (See page 7,
Figure H)
a. Secondar y options
- Door interlock switch can be jumpered
- Miswire or bad connection in module
harness
- Harness not plugged into board properly
- Defective control board
SYMPTOM: Humidifier W on’t Fill
I. Ver ify fill and drain activate with switch in DRAIN
position.
II. Verify red (HL) LED is off.
A. If LED is on, check
1.Water level too high in cylinder
a. Water conductivity very low
b. Cylinder needs replacing
c. Miswire of high voltage electrode wires
d. Foaming water (flush out cylinder)
2. Defective high level circuit
a. Defective high level sensor
- Disconnect low voltage wire (blue), and
verify fill
- Verify no miswire on board -
wait 2 minutes
b. Defective control board
SYMPTOM: Humidifier Won’t Satisfy Space
I. Unit capacity too small
II. High limit humidistat too close to distribution pipe
resulting in tripping
III. Duct air capacity or temperature too low resulting in
trip of high limit
IV. Customer steam potentiometer set too low.
V. Clogged drain system may result in less than 100%
output.
Page 12
MAINTENANCE
NOTE:
It is advisable to inspect the humidifier visually at
approximately two week intervals.
UNIT MAINTENANCE
1. For safety, door interlock disconnects power to
cylinder(s) when door is open. Humidifier may be
operated when door is open by pulling out white
button located above the steam output meter.
CAUTION: HIGH VOLTAGES ARE PRESENT!
2. Green “On” light should be on whenever power is
supplied to the humidifier, and “On-Off-Drain” switch
is in “On” or “Drain” position. If green light is NOT on
check the following:
a. If unit has optional internal circuit breakers they
must be in “On” position.
b. Check each incoming power wire for proper
voltage as shown on humidifier plate.
CAUTION: HIGH VOLTAGES ARE PRESENT!
c. Check green “On” light bulb (24 volt) using volt-
meter.
3. When amber “Abnormal” light is
continually
on check
the following items:NOTE:
Abnormal light will occasionally be on for short periods of time during operaation such as initial startup, during drain cycle and
whenever the switch is in “Drain” position.
a. Clean water strainer.
b. All valves in water supply must be open and water
pressure above 20 psi.
c. Check drain to be sure water is not constantly
draining. Disassemble and clean drain if necessary.
d. Replace cylinder if desired output cannot be reached.
e. Check incoming power wire for proper voltage as
shown on humidifier rating plate.
CAUTION: HIGH
VOLTAGES ARE PRESENT!
f. Check voltage at fill solenoid valve. Replace if 24
volts are present but valve is not open.
g. Check steam hose for any restriction.
4. When amber “Abnormal” light is flashing it indicates
that excessive current has occurred.
a. Turn “On-Off-Drain” switch to “Drain” position.
If water does not drain from cylinder disassemble
and clean drain.
b. If water drains from cylinder turn switch back to
“On” position and allow unit to operate.
c. Mineral build-up in the cylinder may have caused
a short. If this has occurred, replace cylinder.
5. Lights on electronic control module above the
“Increase Steam” control are labeled as follows:
“BD” Used for factor y calibration only.
“HS” If the green light is on it indicates that the
humidistat and other external controls are
closed and are calling for humidification.
“SP” Used for factor y calibration only.
“HL” Red light indicates water has activated overflow
sensor.May be on during initial startup. May
also be on when cylinder is full of minerals and
needs replacement.
CLEANING WATER STRAINER
1. Turn “On-Off-Drain” switch to “Off”.
2. Tur n circuit breakers to “Off ”. (Optional circuit breaker
units only).
3. Shut off water supply valve ahead of unit.
4. Remove brass nut by turning counter-clockwise (A
small amount of water will drain when nut is removed.
Use small container to catch this water.
5. Rinse strainer screen to remove deposits.
6. Reinstall screen, nut, and gasket in strainer housing.
7. Return unit to ser vice.
CHANGING STEAM CYLINDERS
1. Turn “On-Off-Drain” switch to “Drain”. Completely
drain cylinder.
2. Tur n circuit breakers to “Off’ (Optional circuit breaker
units only).
3. Slip off cylinder terminal connectors.
4. Remove steam hose.
5. Loosen cylinder retaining band.
6. Remove cylinder by turning counter-clockwise on
cylinders with threaded connection. Lift cylinders up
on cylinders with unthreaded connection.
7. Replace cylinder using teflon tape or pipe dope on
cylinders with threaded connection. Make sure the
new “O” ring is installed on the cylinder base and
insert cylinders into holder with enough pressure to
seat the “O” ring on cylinders with unthreaded
connections.
8. Tighten cylinder retaining band.
9. Reconnect steam hose and tighten clamp.
10. Reconnect ter minal connectors. NOTE: Match
numbers on terminal connectors with numbers on
cylinders.
11. Turn circuit breakers to “On.” (Optional circuit breaker
units only).
12. Turn “On-Off-Drain” switch to “On.”
13. “Abnor mal” light will remain on until water fills cylinder.
After replacing humidifier cylinder, order a replacement immediately. This will insure having a spare cylinder on hand when the
next change is required. Order model number shown on cylinder
label.
MISCELLANEOUS
If humidification is not going to be required for a long period of
time, e.g. during summer cooling cycle in a comfort application, it
is recommended the steam cylinders be completely drained before
switching off power and closing water supply valve.
“Due to ongoing research and development CARNES reserves the right to change specifications without notice.”
Copyright © 1995 Carnes Company - All Rights Reserved
UNAUTHORIZED MODIFICATION OF THIS HUMIDIFIER OR USING UNAUTHORIZED
REPLACEMENT PARTS MAY CAUSE MALFUNCTION WITH RISK OF SERIOUS
PERSONAL INJURY AND WILL VOID ALL PRODUCT WARRANTIES.
WARNING
!
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