Pure Humidifier ERDDR Series Operation and maintenance manual

1
Deionized, Demineralized, or Reverse Osmosis Water
“ERDDR” Series
Electric Humidifier
Installation Instructions
—————————————————
Operation and Maintenance Manual
READ AND SAVE THESE INSTRUCTIONS
Form No: ERDOM-10-19
Our results are comforting
PURE HUMIDIFIER® and INTAC® are registered trademarks of PURE Humidifier Co.

1
Introduction
To the user of PURE Humidifier Co.’s Electric
Humidifiers
We at PURE Humidifier Co. thank you for choosing one of
our quality products. PURE Humidifier Co. Electric Series
Humidifiers are models of simplicity to install, operate, and
maintain. However, they must be maintained to provide
maximum operating efficiency.
PLEASE READ AND FOLLOW ALL INSTRUCTIONS
CAREFULLY. PROPER OPERATION AND HUMIDITY
CONTROL IS POSSIBLE ONLY WITH PROPER
INSTALLATION AND MAINTENANCE.
The “ERDDR” Series Humidifier is specifically designed to
operate with deionized, demineralized, or reverse osmosis
water. All components that will be in contact with water are
constructed of type 304 stainless steel, incoloy, or corrosion
resistant materials.
Use of mineralized (hard or soft) tap water will cause fill
valve failure and void that warranty. PURE Humidifier Co.’s
“ER” Series should be installed on applications that require
tap water.
High chloride content in feed water can cause chloride stress
cracking and chloride pitting in stainless components.
Chloride stress corrosion cracking (CSCC) and chloride
pitting of stainless steel components is not covered by
warranty. Do not use hydrochloric acid descalers or bleach
to clean the tank. Consult the factory if you are unsure about
which chemical descaler to use.
To ensure proper installation of this product, it must be
installed by qualified HVAC and electrical contractors, and
must be in compliance with local, state, federal, and
governing codes. If installed improperly this product may
cause damage to property, severe personal injury, or death
as a result of electric shock, burns, and/or fire.
Do not adjust any components inside humidifier control box
without consulting the factory.
For indoor use only unless supplied with an Outdoor
Enclosure
Table of Contents
Introduction 1
Capacity & Electrical Specifications 2
Dimensions & Layout 3
Humidifier Layout 4
Location 5
Drain Pan Mounting 6
Injection Tube and Flexible Hose 7
Piping 8
Blower Pack 9-10
Pre-Startup Checklist 11
Non-INTAC® Start-Up Procedure 12
INTAC® Start-Up Procedure 13
Maintenance & Cleaning Instructions 14
Cover Gasket Replacement Instructions 15
Troubleshooting 16
Tool Requirements & Torque List 17
Maintenance Notes 18
Exploded Parts Drawing 19
Parts List 20
The PURE Humidifier Co. Warranty
PURE Humidifier Co. guarantees its products to be free from
defects in material and workmanship for a period of one year
from the date of shipment; provided the product is properly
installed, serviced, and put into the service for which it was
intended.
PURE Humidifier Co. is obligated under the terms of this
warranty to the repair or replacement of the defective part(s),
excluding any labor charges, or to refund the purchase price
at our option. PURE Humidifier Co. assumes no obligation
for incidental or consequential damages. The above
provisions are in lieu of all other guarantees, obligations,
liabilities or warranties, expressed or implied.

2
Capacity & Weights
Electrical Specifications
† The above capacities are based on 100% nominal efficiency. Actual humidifier capacity may
vary due to the heat loss from the humidifier reservoir. The ambient air temperature, air
velocity, and injection tube system will affect the rate of heat loss from the humidifier reservoir.
This can also be affected by makeup water temperature, voltage variations, carryover losses,
heater resistance tolerance, etc.
Standard
Water Unit
Model No.
Steam Output Capacity †
KW
Humidifier Reservoir Weight
Empty Full
lbs/hr kg/hr lbs kg lbs kg
ERDDR-131.4 142 19 70 31.4
ERDDR-394.1 342 19 70 31.4
ERDDR-515 6.8 542 19 70 31.4
ERDDR-618 8.2 642 19 70 31.4
ERDDR-721 9.5 742 19 70 31.4
Standard Water
Unit Model No.
Unit
KW 120V 208V 240V 480V 600V
No. of
Heaters Heater KW Control Circuit Voltage
ERDDR-118.3 4.8 4.2 2.1 1.7 11.0 24 vac
ERDDR-3325.0 14.4 12.5 6.3 5.0 13.0 24 vac
ERDDR-5524.0 20.8 10.4 8.3 22.5 24 vac
ERDDR-6628.8 25.0 12.5 10.0 23.0 24 vac
ERDDR-7714.6 11.7 23.5 24 vac
Single Phase Amperage*
* Other voltages available upon request. Please consult factory for specific availability.
Capacities & Weights

3
Dimensions & Layout
Electrical Control Box
Top View
Drain Valve
Right Side View
Front View
1 1/2ӯ Steam Outlet Connection
1/4”-NPT Fill Inlet
Connection
3/4”- NPT Drain Connection
9.375”
(23.8)
7.375”
(18.7)
16.75”
(42.5)
12.375”
(31.4)
14.625”
(37.1)
11.00”
(27.9)
16.50”
(41.9)

4
Humidifier Layout
Drain & Overflow Outlet
Humidifier Reservoir
Immersion Heaters
Drain Valve
1/4”-NPT Fill
Inlet Connection
SCR Relay &
Heat Sink
SCR Control Module
Water Float Fill
Valve Assembly
Controls Cover
Reservoir Cover
Cover Gasket
Low Water Float Switch

5
Location
The location selected must provide for electrical service,
cold or hot water supply, and sanitary drain.
When selecting a location, try to keep the humidifier
within 10 feet (305 cm) of the duct to avoid unnecessary
heat losses and condensation within the steam supply
line.
Visible “fog” will saturate and condense when it contacts
objects such as turning vanes, filters, fans, elbows, or
take-offs. The warmer the air, the more easily it will
dissipate the visible steam. The most active and
warmest portion of the duct will provide better mixing of
the steam and air. The injection tube should be
mounted a minimum of 2 feet (61 cm) downstream from
an elbow or other uneven airflow area.
Avoid mounting the single-style injection tube closer
than 8-10 feet (244-305 cm) upstream of objects that
could become saturated and condense the steam
(reference paragraph above).
CAUTION: Do not humidify upstream of filters. Consult
factory.
Location of Controls
Fan Interlock Switch
PURE Humidifier Co. recommends the use of an airflow
proving switch or fan interlock to prove airflow prior to
humidifier cooperation. Humidifier operation without
airflow will result in over-saturation of the air stream.
Airflow proving switches are available as optional
equipment from your PURE Humidifier Co.
representative.
High-Limit Humidistat
PURE Humidifier Co. recommends the use of a duct
high-limit humidistat to prevent humidifier operation
when the duct humidity level exceeds 85% relative
humidity. Humidifier operation above 85% relative
humidity can result in over-saturation of the air stream.
High-limit humidistats are available as optional
equipment from your PURE Humidifier Co.
representative. The high limit humidistat should be 12
to 14 feet (365-427 cm) downstream from the humidifier
injection tube.
Smoke Detectors and Temperature Sensors
Smoke detectors should be located upstream from the
humidifier injection tube.
Temperature sensors should be located 12 to 14 feet
(365-427 cm) downstream from the humidifier injection
tube, or past any visible fog travel that may be greater
than this distance.
Injection Tube Installation
The injection tube should be installed in the center of the
duct. See Injection Tube and Flexible Hose Installation
on page 7 for details.
Injection tube should be pitched 2 inches (5 cm) per foot
(31 cm), back to the humidifier. If proper pitch cannot
be maintained, or the injection tube is mounted lower
than the humidifier, a drain “tee” will be required.
Install the tube with the steam ports injecting steam up.
NOTE: If narrow ducts (6”/15 cm or less, in height) are
utilized, install the tube with the steam ports injecting
with the airflow slightly (2 o’clock position).
Galvanized steel duct plates are provided to seal the
opening where the tube enters the duct.
Location

6
Drain Pan Mounting
Drain Pan Mounting
A drain pan is an additional safety feature which may be required to be supplied in the field. In a proper
humidifier installation, a drain pan is not required. However, if the humidifier and injection tube are located in
an area that contains valuable equipment or is a water sensitive area, PURE Humidifier Co. recommends the
addition of a drain pan under the humidifier and under the injection tube. The drain pan should extend past
all edges of the humidifier and if installed in the duct, it should extend a minimum of 3 feet (91 cm)
downstream from the injection tube. The pan should be capable of draining at a rate of 3 gpm. The pan
should be drained to a sanitary drain.
Drain Pan
Humidifier Reservoir and Injection Tube Plan View
Drain Pan
Airflow
Injection Tube
Humidifier Reservoir

7
Injection Tube and Flexible Hose Installation
Installation
Injection tube shall be installed in the center
of the duct. Hose and injection tube should
be pitched back to the humidifier two inches
(5 cm) per foot (31 cm). If proper pitch cannot
be maintained, or the injection tube is
mounted lower than the humidifier, a drain
"tee" will be required (reference drain "tee"
illustration).
Install the tube with the steam ports injecting
steam up. NOTE: If narrow ducts (6”/15 cm
or less, in height) are utilized, install the tube
with the steam ports injecting slightly with the
airflow (2 o’clock position).
The hose connects to the injection tube and
humidifier with stainless steel hose clamps
(by PURE Humidifier Co.).
Galvanized steel duct plates are provided to
seal the opening where the tube enters the
duct.
Δ
Typical “ERDDR” Series
Electric Humidifier
3/4” SW Condensate
drain line (by others)
Δ Minimum water seal of 2” plus duct
static pressure. The water seal
height may have to be increased if
excessive duct static pressure
Open Sanitary
Drain
Flexible Hose
Stainless Steel
Drain Tee
(optional)
Duct (beneath
humidifier)
Flexible Hose
Pitch 2” (5 cm) per foot (31 cm)
back to the humidifier.
Duct Plate
Injection Tube
Pitch 2” (5 cm) per foot (31 cm)
back towards the humidifier.
Duct
Typical “ERDDR” Series
Electric Humidifier 4” Insertion Length/
Duct Width
8”
Tube Detail
1 1/2ӯ

8
Piping
Drain Piping
The drain piping should be copper or stainless steel.
The use of PVC piping is not recommended; the
humidifier water temperature will cause the PVC to
soften and fail. Use a drain tempering kit before
transition to PVC.
If gravity drain is not possible please use a
condensate pump rated for 212°F water or contact a
PURE Humidifier Co. representative to purchase
one.
Water Supply Piping
Recommended supply pressure: 35-50 psi
Maximum supply pressure: 70 psi
This style humidifier utilizes a float-operated fill
valve system which is designed for use with
deionized, demineralized, or reverse osmosis
water. Use of mineralized tap water will cause fill
valve failure and will void the humidifier warranty.
Install stainless pipe on makeup water line within 5
feet of humidifier fill valve connection. If plastic pipe
is used beyond this point a check valve is required
to prevent steam from entering the plastic section
in the event that the water treatment system runs
out of water.
Cold or hot deionized, demineralized, or reverse
osmosis water can be supplied to the humidifier. A
minimum water pressure of 35 psi (2.4 Bar) should
be maintained to provide the proper water level
within the humidifier. DO NOT exceed the
maximum acceptable water pressure of 70 psi (4.8
Bar). If the water pressure is above 70 psi (4.8 Bar)
a pressure reducing valve should be installed.
Δ
Open Sanitary
Drain
3/4” NPT Drain
Connection
1/4”-NPT Fill Inlet
Connection
NOTES
1. All drain piping is by others.
2. Do NOT use PVC or other plastic
piping that is not rated for 220°F or
higher.
Δ Minimum water seal of 2” plus duct
static pressure. The water seal height
may have to be increased if excessive
duct static pressure

9
Optional Blower Pack
In applications where a ducted air system is not
available, PURE offers the optional Blower Pack.
The Blower Pack contains a two-speed
adjustable blower that moves the air over the
steam discharge outlet and disperses the steam
directly into the space (see Fig. 1).
Locating Blower Pack
The distance that visible steam will travel after
leaving the Blower Pack is dependent upon the
relative humidity in the room and the capacity of
the humidifier. If this visible steam comes in
contact with any solid object (walls, beams,
machinery, etc.), it may form condensate and
drip. Refer to Fig. 3 and Table 4 (Table 4 is
located on page 10) for data on visible steam
travel. This will aid you in planning the location
of the Blower Pack.
Remote Mounting
The Blower Pack can be remote-mounted up to
ten feet away from the “ERDDR ” humidifier (see
Fig. 2).
Blower Pack
Air is drawn
into Blower Pack
Steam is discharged
directly into space
“ERDDR” Humidifier
“ERDDR” With Optional Blower Pack
Fig. 1
Visible Rise and Throw
Remote-Mounted Blower Pack
Fig. 2
Remote Blower Pack
“ERDDR” Humidifier
Throw
Rise
Blower Pack

10
Locating Blower Pack
The distance that visible steam will travel after leaving the Blower Pack is dependent upon the relative
humidity in the room and the capacity of the humidifier. If this visible steam comes in contact with any
solid object (walls, beams, machinery, etc.) it may form condensate and drip. Refer to Fig. 3 (Fig. 3 is
located on page 9) and Table 4 for data on visible steam travel. This will aid you in planning the location
of the Blower Pack.
Throw is the horizontal distance the visible steam travels from the steam discharge.
Rise is the vertical distance the visible steam travels from the steam discharge.
Objects in the direct line of the visible steam or objects that are cooler than the ambient temperature may
accumulate condensation.
Note: Data above based on 70°F room temperature.
296/435 CFM Fan
120/1/60*, 2.17 amps
1/15 HP
17”
7 3/4”
Table 4
Left Side View Front View
Optional Blower Pack Dimensions
Fig. 5
Blower Pack weight is 60 lbs (27.2 kg)
* Blower requires a separate 120/1 circuit (by others)
15”
29 1/2”
14 3/4” Steam Inlet
Steam
Discharge
Blower Pack
Visible Steam
Rise & Throw
Humidifier Model
ERDDR-1ERDDR-3ERDDR-5ERDDR-6ERDDR-7
50%
RH
Rise (ft) 1’ 1’ 1’ 2’ 2’
Throw (ft) 8’ 8’ 8’ 10’ 10’
60%
RH
Rise (ft) 2’ 2’ 2’ 3’ 3’
Throw (ft) 13’ 13’ 13’ 14’ 14’

11
Pre-Startup Checklist
Pre-Startup Checklist
Before starting the “ERDDR” PURE Humidifier Co. Electric Humidifier, check the following installation
items:
______ 1. MOUNTING - Verify that the humidifier evaporating chamber is securely supported and that the
evaporating chamber is level in both directions. If humidifier is installed above equipment or not located
near a floor drain than a drain pan should be installed below the humidifier steam generator.
______ 2. INJECTION TUBE - Verify that the humidifier injection tube is mounted within the duct with the proper
pitch back to the humidifier (2”/5 cm per foot / 31 cm). NOTE: If the humidifier evaporating chamber or
the flexible hose (optional) is mounted higher than the injection tube, a drain “tee” is required to drain the
condensate out of the injection tube steam line. If it is an Insty-Pac or Fast-Pac, refer to the respective
O&M to determine if they are mounted properly and have the proper p-trap size.
______ 3. ELECTRICAL - Verify that all wiring connections have been connected in accordance with the wiring
diagram. CAUTION: Live power may exist in the control cabinet. Turn off the main power at the
disconnect switch before verifying the electrical connections!
______ 4. SAFETY CONTROLS – The supply air duct RH high-limit should be installed at least 10 feet
downstream from the humidifier tube. Any other control sensors should be at least 10 feet
downstream from the humidifier tube. Smoke detectors should not be installed downstream of the
humidifier tube. If a smoke detector absolutely has to be installed downstream from the humidifier
tubes then it should be installed as far from the tubes as possible.
_____ 5. PIPING: Water Supply - Verify that all piping connections have been completed as recommended and
that water pressure is available to the humidifier. Verify that the supply water pressure is 35-50 psi.
There should be at least 5 feet of metal pipe and check valve between the tank and any plastic pipe.
_____ 6. PIPING: Steam Outlet - Refer to attachment for proper outlet steam piping from the generator to the
tube(s). Any horizontal to vertical up transition in the outlet steam pipe requires a water-sealed
drip leg! Improper outlet steam piping will cause steam to leak from the steam generator. Runs over
20 feet long may require upsizing of the steam pipe.
Signature:__________________________ Date:_________

12
Non-INTAC® Start-Up Procedure
Start Up Procedure
______ 1. Close the humidifier manual ball valve.
______ 2. Turn the controlling humidistat to the lowest setting (no call for humidity).
______ 3. Open the water supply on/off isolation valve (by others) and allow the humidifier evaporating chamber
to fill to the proper level.
______ 4. Turn the electric power “on” to the humidifier.
______ 5. Make sure all the optional safety switches are satisfied (airflow proving switch, high-limit humidistat,
etc.).
______ 6. After the humidifier is full of water, turn the humidistat up to call for 100% humidifier demand.
______ 7. Verify the low water safety circuit by opening the drain valve and closing the water supply on/off
isolation valve (by others). As the humidifier tank is draining, the contactor should pull out and remain
off; this indicates the low water safety circuit is operational.
______ 8. Close the drain valve, open the water supply on/off isolation valve (by others) and allow the humidifier
to fill to the proper level.
______ 9. Once full the heater(s) should energize on a call from the humidistat.
______ 10. Check operation of optional field-installed safety switches (airflow proving switch, high-limit humidistat,
etc.) to make sure that they turn the power off to the control circuit power. The safety switches should
shut off the humidifier contactor whenever one or more of the optional safety switches create an “open
circuit”.
______ 11. Check heater amperage draw by testing and recording voltage and amperage. Readings should match
the factory heater nameplate.
Amps :_______
______ 12. Inspect installation for leaks by operating humidifier at a full rolling boil. This may take up to 15 minutes
from a cold start. Any leaks should be sealed. Just tightening a pressure clamp will not work if the
gasket is not properly positioned between the sealing surfaces. If necessary, remove the cover, reseat
gasket and replace cover. A small amount of adhesive (super glue, gorilla glue, spray adhesive, etc.)
to hold the gasket in place while repositioning the cover will aid in this process.
______ 13. After the unit is producing steam, check and retighten all hose clamp connections in the system and
make sure they are torqued to 35-40 in-lbs.
Signature:__________________________ Date:_________

13
PURE Humidifier Co. “ERDDR” Maintenance Instructions
The “ERDDR” Series Electric Humidifier is practically maintenance-free. However, the humidifier should
be inspected and placed on a dedicated maintenance schedule to ensure continued operation of the
humidifier and its accessories. PURE Humidifier Co. recommends that the following items be
inspected, and/or, cleaned on a minimum basis of twice a year. If excessive mineral buildup
occurs, the maintenance schedule should be increased.
Maintenance & Cleaning Instructions
Inspect/Maintenance Item
Water makeup float valve
Low water float switch
Safety interlocks
(airflow, high-limit)
Immersion heaters
Humidifier cover/tank
Flexible hose
Procedure to Follow
Check to make sure the fill valve is operating
properly. If the valve appears to continually fill,
check the valve adjustment or valve seat and seal
(see Troubleshooting instructions).
Check to make sure the switch will shut the
humidifier off when the water level drops too low.
Open the drain valve to allow water to drain out for
checking purposes. Make sure to close the drain
valve after inspection is completed.
Check to make sure the safety interlocks (airflow,
high-limit, etc.) will shut down the humidifier.
Verify the correct amperage is being drawn by the
heating element. Reference the wiring diagram
for correct amperage.
Inspect for any leaks. Repair as required.
Remove the heater assembly and remove mineral
deposits from floor of the humidifier reservoir.
Inspect for cracks or leaks. It is normal for the
hose to become hard and develop a “set”.
Replace as needed.
Cleaning Instructions
Normally ERDDR reservoirs do not need to be cleaned when fed with high purity water. If fed with low
purity water reservoir cleaning may be needed. The tank should be cleaned manually from the
reservoir cover. Turn off the water supply on/off isolation valve (by others). Turn off power to the unit,
disconnect steam supply hose and remove cover. Remove all loose solids with a wet vacuum,
stainless steel brush, scouring pad, putty knife and/or bucket. Heaters should also be cleaned and
loose buildup removed by hand (if applicable). After removal of solids and replacing the cover you
may wish to add a de-scaling solution. DO NOT use Hydrochloric acid-based de-scalers; this will
corrode stainless steel. PURE Humidifier Co. recommends the use of a vinegar, citric acid, diluted
phosphoric acid or diluted nitric acid-based cleaner. Follow all precautions on the cleaner packaging.
Some cleaners will give off overwhelming and noxious odors, so make sure there is proper ventilation
in the working area and the steam outlet pipe is removed so that fumes are not spread throughout the
building. After cleaning the tank, flush the tank multiple times to remove any remaining acid. Drain
tank completely and allow the tank to air dry for a few hours. This will ensure that the outer protective
layer of the stainless steel will passivate and ensure corrosion resistance.

14
Cover Gasket Replacement Instructions
Installation
Remove cover. Fit the gasket around the entire lip of the tank opening. Cut the gasket 1/8” longer than
required, this will ensure proper fit when the cover is clamped back on. Slide the gasket onto lip of tank
around the entire perimeter, and seal the ends together with a small amount of silicone.
Plan View of Humidifier
Section View of Gasket
Gasket Bottom
Notch here
Bottom View of Gasket
Notch gasket bottom only
Gasket Top
DO NOT NOTCH

15
Troubleshooting
Problem
Humidifier will not heat
Humidifier will not fill
Humidifier will not stop
filling or is short cycling
Possible Cause
Blown heater fuse(s)
Control transformer not
producing 24 vac control
voltage
Safety controls open
(airflow switch, high-limit, etc.)
Over-temp switch
Faulty humidity sensor
Faulty immersion heater
No water pressure
Drain valve open
Faulty water float valve
Fill valve stuck open
Drain valve open
Recommended Action
Check and replace.
Check transformer output.
Verify voltage across terminals #9 (hot) and #10
(comm).
Verify that all safety controls are completing the
safety circuit.
The level control circuit has interference or is
damaged. Mineral on low water float switch may
be preventing the switch from opening on low
water condition. Consult factory if you are unsure
of the source of the problem.
Verify voltage to and from humidity sensor.
Check and verify heater voltage and
amperage. Compare to diagram or
nameplate label ratings.
Check water supply.
Close drain ball valve.
Check float valve seat for dirt.
Check float valve seat for dirt.
Adjust float ball arm.
Check float ball for leaks.
Close drain ball valve.

16
Recommended Maintenance Tool List
7/16” Wrench
5/16” Nut Driver or Socket
11/32” Nut Driver or Socket
5/32” Nut Driver or Socket
Pliers
Flat head screwdriver
Wire stripper
Wire crimper
Tool Requirements & Torgue List
Torque List
Cover Bolts 18 inch/pounds MAX
Hose Cuff Screws 35-40 inch/pounds MAX when hot
Heater Nut 18-20 foot/pounds*
Heater Electrical Terminal 35 inch/pounds
* Use a pliers to hold heater sheath from twisting.
Cover
Heater Fiber Gasket
Heater Nut
Electrical Terminal Nuts
Metal Washer
Heating Element Sheath
Isolator
Heater Assembly Sectional Detail

17
Maintenance Notes
Maintenance Notes
Maintenance Performed Date By

18
Maintenance Notes
Maintenance Notes
MaintenancePerformed Date By

19