Nortec MES Electrode Steam Humidifiers User Manual

MES Electrode
Steam Humidifiers

Installation, Operation,

Maintenance, Spare Parts, and

Exploded Views Guide

IMPORTANT: Read and save this guide for future reference.

This guide to be left with equipment owner.

Form 08-111

Table of Contents

INSTALLATION 1

RECEIVING EQUIPMENT .........................................1

PRINCIPAL OF OPERATION .......................................1

WATER SUPPLY AND PLUMBING ....................................2

WATER CONNECTION ..........................................2

START-UP AND OPERATION .......................................2

CAPACITY ADJUSTMENT.........................................3

CYLINDER REPLACEMENT........................................3

WHEN TO REPLACE THE STEAM CYLINDER .............................3

REMOVING THE OLD CYLINDER ....................................4

INSTALLING THE NEW CYLINDER ....................................4

MAINTENANCE 4

EXTENDED SHUTDOWN .........................................4

TROUBLESHOOTING 4

TERMS USED ...............................................4

STARTING POINT .............................................5

DIAGNOSTIC PROCEDURES TROUBLE-SHOOTING TIPS .......................7

SOFTWARE REQUIREMENT FOR MODBUS RTU ............................8

PHYSICAL DIMENSIONS DIAGRAM ...................................11

WIRING DIAGRAM ............................................12

SPARE PARTS LIST ...........................................14

EXPLODED VIEWS DIAGRAM ......................................15

INSTALLATION

2

S

RECEIVING EQUIPMENT

1. Check packing slip to ensure ALL material has
been received.

Figure #1

CONDENSATE RETURN

(OPTIONAL)

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a

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S

c

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e

m

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2. Inspect box for damage and note on shipping
waybill accordingly.

3. After unpacking, inspect unit for damage and if
damage is found, advise shipper as soon as
possible.

4. Inspect unit (humidifier) to ensure it is the
correct model, phase, and voltage. If any are

1. INLET CHAMBER

. FILL CHAMBER

3. WATER OVERFLOW
CHAMBER (SAFETY DRAIN
IN CASE OF FILL VALVE/
CONTROL BOARD FAILURE)

FILL
CUP

1” AIR
GAP

3

2

1

STEAM HOSE

ELECTRODE

CYLINDER

incorrect, advise the factory or your local
representative immediately.

NOTE: All products are shipped on an F.O.B.
factory basis. Any and all damage, loss, or breakage
claims are to be made directly to the shipping
company.

The NORTEC MES-U/MES-P electrode humidifier

STRAINER

TAP

WATER

SUPPLY

FILL

VALV E

CONNECTION

DRAIN

DRAIN
VALV E

DRAIN CANAL

(OPEN TO ATMOSPHERE)

DRAIN
PAN

is the culmination of many years of research and
development in the electrode humidifier industry. This
unit has been built by skilled craftspeople and
thoroughly tested before shipment and should, if the
following instructions are observed, provide many
years of trouble-free operation.

An electronic timer uses the rate of amp fall to

determine the water level. The objective is to

FOR HUMIDIFIERS INSTALLED IN THE CITY
OF LOS ANGELES: A city of Los Angeles approved

spring-loaded double ball CHECK VALVE should be

concentrate current-carrying minerals in the cylinder
so that a smaller volume of water is required to
produce the rated steam output.

supplied and installed by the contractor on each of the
potable water inlets to each humidifier.

This achieves the longest life for the disposable

cylinder because of minimal electrode coverage and

Recommended valve manufacturer: Watts
Regulator (phone [phone]), model #7, size 3/8”

use of less energy because the high concentration
allows a minimal drain rate.

NPT inlet and outlet.

When 80% F.L.A. is reached, the fill valve will

Each drain line from these humidifiers shall be
routed, without dips or sags, to terminate above the
flood level rim of a City of Los Angeles approved
indirect waste receptor.

No combustible materials shall be placed in the
duct and/or the air plenum.

open refilling cylinder to 100% F.L.A. On occasion,
the drain valve will also come on if water level is too
low, indicating too high a concentration and the
requirement for a dilution of the water in the cylinder.

If the water reaches top of cylinder before 100%
F.L.A., the fill valve shuts off via the sensor and
fill-boil-fill-boil cycle continues, cycling off the red high

PRINCIPAL OF OPERATION

water sensor light until the concentration becomes
high enough to reach 100% F.L.A. The above
described control process will then take over.

When the humidistat calls, the cylinder fills to
100% of the Full Load Amperage (F.L.A.) or to the top
of the cylinder, whichever comes first. See Figure #1.

If it reaches 100% F.L.A. the water heats and boils
away to a level giving 80% F.L.A.

-1-

WATER SUPPLY AND PLUMBING

1. The fill valve is sized for an extended water
pressure range of 30 to 80 psi.

2. For cases below 15 psi add a pressure boost
pump, notify the factory and a fill valve with an
oversized orifice will be supplied.

are designed for water pressure from 30 to 80
psi and are protected by the built-in strainer.

4. For inlet water pressure outside this range, the
factory should be contacted. (See Water
Supply and Plumbing section of this manual.)

START-UP AND OPERATION

3. For cases above 80 psi, install a pressure
reducing valve in the water feed line to the
unit.

4. With extremely dirty or muddy water sources,
e.g., some well sources, ensure proper
filtration by adding an external filter to the
water line entering the unit. (Consult factory
for accessories such as filters.)

5. DO NOT use completely demineralized water
with this unit as it is the minerals that allow the
electrode principle to work.

6. DO NOT use a hot water source as it will
cause deposits that will eventually block the fill
valve orifice.

Figure #2

Bottom View of MES-U/MES-P Unit

3/8" Cold Water

Olive Connection

· Ambient temperature location for humidifier:
41ºF - 104ºF (5ºC - 40ºC).

· Relative humidity location for humidifiers:
5% rh - 80% rh.

Check to see that the unit is securely mounted on
a level surface with the proper drain and water supply.
Check for correct voltage with appropriately sized
service. Check that the steam distributor, steam
supply hose, and condensate line are correctly
installed and routed back to the unit. Ensure that the
external control humidistat is located in an area to
properly sense the relative humidity to be maintained
by the humidifier, and that the interconnecting low
voltage wires between the humidistat and the unit’s
control terminal strip are in accordance with the wiring
diagram.

Check all electrical connections for wires which
may have become loose in shipping. Components
damaged due to loose connections are NOT under
warranty.

Check electrode plugs to ensure they are pressed
firmly onto the electrode pins. Important: Loose
connections will cause overheating of the cylinder
plugs, possibly melting the plugs and/or cylinder.

7/8" Drain
Connection

Use 7/8" I.D. Hose From Factor

.

WATER CONNECTION

1. A copper compression olive type coupling for
1/4" O.D. soft copper tubing is provided with
unit and requires no soldering for the water
connection to the unit. See Figure #2.

2. An isolating valve should ALWAYS be placed
in the feed water line allowing service of the fill
valve.

3. Each unit is fitted with a fill solenoid valve
located on the base drain pan. Flow orifices

Open the isolating valve in the feed water line to

the unit.

y

Make sure the humidistat is set high enough to call

for humidification.

Turn on the main disconnect in the primary service
feeding the unit and check that unit has power at the
primary terminal block.

PUSH THE AUTO ON/OFF/DRAIN SWITCH TO
“ON”.

Water will start to enter the cylinder through its
bottom port and rise in the cylinder to a point
determined by the solid-state control circuitry.

It is not unusual upon initial start-up for the
water to fill the cylinder and cycle on the red high
water sensor light.

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The red light simply acts as a safety to shut off the
fill valve and prevent over-filling. With the red light on,
the water in the cylinder will continue to heat and, after
a few minutes, start to boil. After the boiling action of
the water has lowered the water level below the
sensor at the top of the cylinder, the red light will go
out and the fill solenoid will again open until the
cylinder is again full.

This cycling of the red light and fill valve will
continue until the unit’s full output capacity is reached
after which the water level will automatically lower
itself in the cylinder. (The increased concentration
allows for lower electrode coverage while maintaining
the same output.) When a stabilized condition is
reached the water will be boiling close to the cylinder
seam level. The solid state circuitry will maintain the
proper concentration in the cylinder by introducing
short drains only when necessary.

If the cylinder is manually drained the above
process will repeat itself.

Figure #4

MES-P Adjustable Pot

CYLINDER REPLACEMENT

After an extended period of operation, in
accordance with life expectancy information, the
cylinder is completely used as indicated by the red
high water sensor light illuminated on the cabinet.
When this condition is reached, a new replacement
cylinder is to be installed.

Low Water Conductivity

Should normalization of the unit be required
immediately after start-up, the installer may speed up
the process by artificially increasing water conductivity.
During a fillcycle, the installer should dissolve half a
teaspoon of table salt (no more) in a cup of water and
add it to the cylinder by means of the fill cup attached
to the plumbing section.

Open the plumbing compartment and add salt
solution through cylinder outlet. Excessive amounts of
salt will result in erratic operation of the unit; however,
normalization of the unit will occur automatically
through the solid-state control sequence.

CAPACITY ADJUSTMENT

The MES-U/MES-P series of humidifiers come
with adjustable capacity (AC) PC boards. These
boards have a pot to adjust the output from 20 to
100%. See Figures # 3 and 4.

Figure #3

MES-U -Adjustable Pot

NOTE: Red light may come on during initial
start-up but does not mean cylinder replacement. See
Start Up and Operation section of this manual.

Consult factory or agent for replacement. Quote
the cylinder model from the white 3-digit label on the

Figure #5

Cylinder Removal

Ad ustab le

Adjustable

Capacity Pot

Capacity Pot

cylinder or quote model, voltage, and serial number
from unit specification label.

WHEN TO REPLACE THE STEAM CYLINDER

The steam cylinder is disposable and must be
replaced at the end of cylinder life. Cylinder life is

-3-

dependent on water supply conditions and humidifier
usage. Failure to replace the cylinder at the end of
cylinder life may result in unit damage. NORTEC is not
responsible for any damages resulting from, or
attributable to, the failure to replace a used cylinder
(see Manufacturer’s Warranty).

INSTALLING THE NEW CYLINDER

1. The reverse procedure should be followed to
install a new cylinder. The main disconnect is
to be left open until the cylinder is completely
installed and reconnected.

REMOVING THE OLD CYLINDER

See Figure # 5.

n

1. Turn off the water supply to unit.

2. The old cylinder must be drained completely
before removing. This is done by pushing the
auto on/off/drain switch to the “drain” position.

3. When completely drained, push the auto
on/off/drain switch to the “off” position.

4. Open the main disconnect during the entire
cylinder change operation.

5. The power wires to the cylinder are attached
by cylinder plugs to the electrode pins on top of
the cylinder. Pull these plugs vertically off the
pins. See Figure # 5.

6. Using slot screwdriver, loosen the steam hose
clamp(s) and pull steam hose off vertically.

7. The cylinder is now ready to be lifted out of the
unit.

Figure #6

Plugs

White
Sensor Plug

Sensor Pin

Cylinder
Plug

1Ø

2. Ensure that the cylinder mounting stubs are
seated properly in the allotted side mounting
slots within the unit.

3. The white sensor plug on all units is for the
sensor pin, which always goes on the single
pin offset from the others. See Figure # 6.

4. Ensure that cylinder plugs are very snug on
the pins.

5. Replace loose fitting plugs, loose plugs may
generate enough heat to melt and destroy the
plug and new cylinder plugs must be ordered.

MAINTENANCE

WARNING! The plumbing and electrical

compartments contain high voltage components and
wiring. The access cover is attached with screws.
Access should be limited to authorized personnel
only.

EXTENDED SHUTDOWN

Before disconnecting power to the humidifier for a
period of extended shutdown, ALWAYS DRAIN the
cylinder first. Otherwise, the electrodes are subject to
harmful corrosion which drastically shortens the
cylinder life. Do NOT leave the switch in the DRAIN
position indefinitely as the drain coil could burn out.
Leave the switch in the OFF position and “open” the
main external fused disconnect to stop power to the
humidifier. Close the shut off valve in the water
supply line feeding the humidifier.

Cylinder Pin

Cylinder Pin

Sensor Pin

Cylinder Pin

Cylinder Pin

Cylinder Pin

3Ø

TROUBLESHOOTING

TERMS USED

F.L.A. (Full Load Amps): Refers to amps listed on
the humidifier specification label.

SHORT CYCLING: When the ‘on time’ of the
humidifier is less than ten minutes upon a call for
humidity. To correct short cycling, all humidifiers have
a capacity adjustment which allows the output of the
humidifier to be reduced to as low as 20% of rated
output, thus extending the ‘on time’ required to
maintain output.

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