Nortec NHDI, NHSC User Manual

NHSC / NHDI
Resistive Element
Steam Humidifiers

Installation, Operation,

Maintenance, and

Troubleshooting Guide

NHSC

NHDI

IMPORTANT: Read and save these instructions. This
guide to be left with equipment owner.

Form #04-197-1 1505921

Table Of Contents

INSTALLATION 1

RECEIVING & UNPACKING EQUIPMENT ................................1

PRE-INSTALLATION CHECKPOINT ...................................1

BASIC HUMIDIFIER CONFIGURATION..................................1

LOCATION & MOUNTING .........................................2

HUMIDIFIERS ·············································2

BLOWER PACKS ···········································3

STEAM DISTRIBUTORS AND SHORT ABSORPTION MANIFOLD ·················3

PLUMBING .................................................6

WATER SUPPLY LINE ········································6

DRAIN LINE ··············································6

STEAM LINE AND CONDENSATE RETURN LINE ··························7

ELECTRICAL................................................7

PRIMARY VOLTAGE SUPPLY WIRING TO HUMIDIFIER ······················7

PRIMARY VOLTAGE SUPPLY WIRING FROM HUMIDIFIER(S) TO BLOWER PACKS ·······7

LOW VOLTAGE CONTROL WIRING ·································9

CONTROL INSTALLATION ······································9

OPTIONAL MODULATION (CONTINUOUS CONTROLS)······················10

OPTIONAL MODULATION (CONTINUOUS CONTROL) PACKAGES BY NORTEC ········11

OPERATION 11

INTRODUCTION .............................................11

LAYOUT AND FUNCTION ........................................11

LEVEL REGULATION ········································11

STEAM GENERATION REGULATION································12

FLUSHING ··············································12

SCALE COLLECTOR TANK ·····································12

NHSC/ NHDI OPERATION ........................................12

STARTING OPERATION ·······································12

INTERROGATION OF THE OPERATING STATUS ···························14

MAINTENANCE..............................................17

NOTES ON MAINTENANCE .....................................17

DISMANTLING AND REASSEMBLYWORK .............................18

NOTES ON CLEANING........................................18

FAULT ELIMINATION ........................................19

SCALE TANK SERVICING ......................................20

REPLACING UNIT FUSES ......................................21

RESETTING FAULT INDICATION“ERROR” .............................21

HEATING ELEMENT REPLACEMENTINSTALLATION INSTRUCTIONS ................21

TROUBLESHOOTING ··········································23

CONTROL CIRCUIT TERMINALBLOCK .................................25

PRE-START-UP CHECKLIST ......................................26

START-UP CHECKLIST .........................................27

MAINTENANCE CHECKLIST .......................................28

EXPLODED VIEWS ............................................30

WIRING DIAGRAMS ...........................................34

INSTALLATION

.

as indicated on the spec label. Refer to local
codes.

RECEIVING & UNPACKING EQUIPMENT

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

2. All material shortages are to be reported to
NORTEC within 48 hours from receipt of
goods. NORTEC assumes no responsibility
for any material shortages beyond this period.

3. Inspect shipping boxes for damage and note
on shipping waybill accordingly.

4. After unpacking, inspect equipment for
damage and if damage is found, notify the
shipper promptly.

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

PRE-INSTALLATION CHECKPOINT

1. Ensure that available voltage and phase
corresponds with humidifier voltage and phase
as indicated on humidifier’s spec label (see
Figure #1).

3. Report any discrepancy immediately.

BASIC HUMIDIFIER CONFIGURATION

NORTEC NHSC / NHDI humidifiers share a
modular sheet metal cabinet. Each unit has a right
side electrical compartment. Each electrical
compartment has a hinge-down front door which is
removable from any partially or fully opened position.
Each electrical compartment has a screw-mounted
right side cover which can open for ease of electrical
connection. For safety, the door when closed keeps
the side cover from being opened.

Single units have a plumbing compartment
attached to the left side of the electrical. Double units
have a second plumbing compartment. Each
plumbing compartment has a hinge-down front door.
For safety, the door must be closed in order to engage
the safety interlock. To avoid any danger, never
operate the humidifier with a door off.

To open the doors, unlock, lift door up slightly and
pull top of door forward. Door will hinge 180 degrees
and hang straight down. To remove door, swing door
parallel to floor. Then lift up slightly and out. To
reinstall door, hold parallel to floor and insert hinge
pins at bottom.

2. Ensure that the dedicated external disconnect
is of sufficient size to handle the rated amps

Figure #1

NHSC / NHDI Series Humidifier

SteamOutlet

1.75" O.D.

Water

Supply

NOTE: NHDI does not have the scale collector tank.

Scale
Collector
Tank

Spec
Label

Drain
Valve

Optional SSR
Cooling Fans

Keypad
Display

Power and
Control
Wiring

Figure #2

Minimum Steam Line Clearance

Min. 10 Degree Slope

Min. 12"

Trap

* See Section On

Condensate

Return Line

NOTE: Trap must be 3' minimum down from steam distributor
If not, condensate must be routed to drain.

-1-

Figure #3

Clearance Required (Top View)

Condensate Return

Steam Outlet

NOTE: Local and national codes may deviate, please
consult applicable codes for clearance requirements.
Right side min. 36" side clearance. Min. 36" frontal
clearance recommended see note.
Top 12” Min, Bottom 12” Min, and Left Side 2” Min.

LOCATION & MOUNTING

HUMIDIFIERS

Right Side

Front

1. Location of the humidifier should be below and
as close as possible to the steam distributor
location. If possible, DO NOT locate humidifier
any further than absolutely necessary from
steam distributor location, as controllability
and net output will be reduced as a result of
heat loss through the steam hose (see Steam
Distribution Engineering Manual).

2. Where possible, mount humidifier at a height
convenient for servicing.

3. Wall mounting bracket provided should be
securely attached horizontally and open edge
facing upwards, using field-supplied fasteners.
For a single unit, use a minimum of 4 - #12 x
3” long wood screws. For a double unit, use a
minimum of 6 - #12 x 3” long wood screws.
These screws must be fastened securely on a
2 x 4 wood stud or equivalent support. If any
spacer material is used between the bracket
and the structural material such as drywall,
increase fastener length accordingly. In
addition, install a minimum of 2 field supplied
fasteners in the holes provided in the back of
the unit to prevent the unit from being bumped
off the wall bracket. See Figure #4.

NHSC / NHDI Series humidifiers are designed to
mount on a suitable wall or vertical surface. Do not sit
the unit on floor due to clearances required for
plumbing, electrical, and control entrances. The
clearance dimensions shown in this manual are for
reference only and are the minimum required for
maintenance of the humidifier. Local and National
Codes should be consulted prior to final location and
installation of the humidifier. NORTEC will not accept
responsibility for installation code violations.

Figure #4

Wall Bracket Mounting

Frontal clearance min. 36" (91 cm)
Right side clearance min. 36" (91 cm)
Left side clearance min. 2" (5 cm)

Wall

7.7"

(19.6 cm)

4. Mount unit on hanging bracket after ensuring
the bracket is properly anchored to the wall.
Raise the unit and place it on the hanging
bracket ensuring that the flanges in the
mounting bracket are properly aligned and
centered with the flanges of the unit. Push the
unit in towards the wall to properly interlock
the two flanges. Note: This will result in the
unit shifting slightly down. Ensure that the
hanging bracket’s flanges are fully engaged

Figure #5

Installation of the Scale Tank Bracket (NHSC only)

1.

2.

1) Line up holes in bracket with

3.

1.

holes in drain pan. Fasten the
bracket to the drain pan using
the four Nylon lock nuts
provided.

2) Fasten the front of bracket
with the two #10-24 self tapping
screws provided.

3) The two locking screws for the
bracket should already be
installed.

-2-

and visible from within the plumbing section of
the unit, and that the unit’s flanges are
properly contained within the wall bracket.

5. Install tank bracket. See Figure #5. (NHSC
Version only). Mounting the scale tank. (NHSC
Version only).

Figure #6

Remote Mounted Blower Pack

Figure #7

Remote Mounted Blower Packs (RMBP)

23.0"

(58.4 cm)

11.0"

(28.0 cm)

Condensate

Steam

Power

14.2"

(36.2 cm)

2.9"

(7.3 cm)

Wall

Mounting

Bracket

Remote

Mounted

Blower Pack

Scale
Collector
Tank

6. Make sure humidifier is level.

7. DO NOT mount humidifier on hot surfaces.

8. If humidifiers are mounted on roof, a
thermostatically ventilated weatherproof

Typical Remote Mounted Blower Pack Installation

Figure #8

Dimensions Shown
Are Steam Line Connections
Allow Minimum 12" (31 cm)

7.7"

(19.5 cm)

7.2"

(18.2 cm)

Clearance On Each Side

cabinet provided by others should be used.
Consult factory.

9. DO NOT mount humidifiers on vibrating
surfaces or duct work.

BLOWER PACKS

1. Blower packs are an optional accessory used
to directly distribute steam to localized areas
(such as computer rooms) or in structures that
do not have a built-in air distribution system.

Remote Mounted Blower
Packs (RMBP) Only

NHSC

uses Nortec steam
hose 1.75" O.D.or
stainless steel pipe.

uses Nortec steam

3"

Min. Trap
Height 3"
Required

Humidistat

Scale

Collector

Tank - NHSC

Water

Supply 3/8”

Drain Line

1.75” O.D.

Air

Gap

NHSC / NHDI using a Remote Mounted Blower Pack (RMBP)

NHDI

hose 1.75” O.D. or
stainless steel pipe.

Do not exceed 10 ft
when using steam hose.

Steam Line
Connection

LCD Keypad
Display with
LED Status

Low Voltage
Controls Wiring
24 Vac

Primary Wiring
Copper Funnel

Drain (by others)

-3-

2. All NHSC / NHDI Series blower packs consist
of a steel cabinet containing: blower/motor
powered by voltage directly from the
humidifier, fuse, relay, speed select switch,
stainless steel steam distributor, supply air
grille with adjustable louvers, and a built-in
manual reset safety thermostat to turn off the
humidifier if the blower pack gets overheated.
Control thermostat, mounted on the steam
distributor, starts the fan when steam is
generated. When supply voltage differs from
voltage required to run blower motor, the
blower pack will contain the proper
transformer. All blower packs provide intake
air filters, if required.

3. For installation details about the blower pack,
please refer to the blower pack installation
manual located in the blower pack box, Form
#XX-277.

STEAM DISTRIBUTORS AND SHORT
ABSORPTION MANIFOLD

1.1. Steam distributors are an optional accessory
used to directly distribute steam to localized
areas (such as computer rooms) which are
served by ducted air. These distributors are
made of stainless steel and are mounted level
to the duct.

6. For installation details, please refer to the
installation manual located in the Steam
Distributor box, Form #XX-231.

7. For calculating absorption distances, refer to
H.E.L.P. Software or the Steam Distribution
Engineering Manual, Form #XX-232.

2. The SAM-e optional accessory has the same
function, to distribute steam inside a duct. The
only difference is that this system is designed
to reduce the absorption distance of the steam
in the duct by optimizing the steam
distributors.

3. Each cylinder requires its own steam line

and at least one distributor (do not join two
or more cylinders to one larger steam line).

Any cylinder’s steam line may be divided into
multiple branches to feed more than one
distributor. Steam supply line “tees” are
common stainless fittings that are available for
this purpose.

4. Steam distributor locations are typically as
follows: supply air duct, return air duct, air
handling unit. Proper location should
consider: air temperature, relative humidity
before the distributor, air velocity, dimensions
of the location, amount of steam being
introduced into the duct, downstream
obstructions, and surfaces vulnerable to
wetting.

5. The NHSC / NHDI can overcome 6” of W.C.
duct static pressure max. Consult the factory
if you exceed 6” of W.C.

-4-

SAM-e

static pressure

Trap depth

2” greater

than duct

Min
24”

Condensate return

to floor drain, sump

pump or back to the

humidifier

Supply 3/8”

Steam
Inlet

Collector

Drain Line

1.75" O.D.

Water

Figure #9

Typical AHU / Duct Application using a SAM-e

NHSC

uses Nortec steam
hose 1.75” O.D. Or Med.
L Copper Insulated

NHDI

uses Nortec steam
hose 1.75” O.D. or
stainles steel pipe.

Do not exceed 10 ft

Gap

Air

when using steam hose.

Steam Line
Connection

LCD Keypad
Display with
LED Status

Low Voltage
Controls Wiring
24 Vac

Primary Wiring
Copper Funnel

Drain (by others)

Scale

Tank

NHSC

Humidistat

NHSC using a Short Absorption Manifold(SAM-e)in Duct/AHU

Figure #10

Typical Duct Application using Standard Distributor

NHSC

uses Nortec steam
hose 1.75” O.D. Or Med.
L Copper Insulated

NHDI

uses Nortec steam
hose 1.75” O.D. or
stainles steel pipe.

Do not exceed 10 ft
when using steam hose.

Steam Line
Connection

LCD Keypad
Display with
LED Status

Low Voltage
Controls Wiring
24 Vac

Primary Wiring
Copper Funnel

Drain (by others)

Condensate trap

must be 2” greater

than duct static

pressure.

Steam
Inlet

Min
24”

Scale

Collector

Tank

NHSC

Drain Line

1.75" O.D.

Water

Supply 3/8”

Humidistat

Air

Gap

NOTE: NHDI does not have the scale management system.

-5-

PLUMBING

All water supply and drain line connections
should be installed in accordance with local
plumbing codes and should be copper or other
material suitable for potable water at 140ºF (60ºC).

WATER SUPPLY LINE - NHSC

1. The humidifier is intended to operate on
potable water.

2. Standard fill valves are sized for water
pressure ranging from 30 to 80 psig. For other
pressures, consult factory. This pressure
should be measured at the humidifier if the
water pressure is suspect.

3. ALWAYS supply and install a shut off valve in
the fill water supply line dedicated to the
humidifier to facilitate servicing. Use ½" OD
copper to within 4 feet of the humidifier.
Reduce to 3/8" OD and connect to the
factory-supplied 3/8" olive compression fitting
under the humidifier.

4. Same installation as #3, but add Drain Water
Cooler instead of fill.

#11). A field-supplied funnel (see Figure #12)
is recommended. It will prevent backup in the
drain pan and in the cylinder due to partially
blocked or badly installed drain lines. This
prevents rusting of the drain pan.

2. The NHSC scale collector tank is also
equipped with its own drain. It is
recommended to pipe, with a flex hose, the
scale collector tank to allow drainage, if
required while maintaining ease of servicing
(DO NOT HARDPIPE).

3. The drain line should not end in a sink used
frequently by personnel, or where plumbing
codes prohibit it. Route to a floor drain or
equivalent for safety reasons, since drain
water from humidifier can be very hot.

4. Keep drain lines as short as possible. Keep

drain lines sloped down, not level and not
up since low spots in drain lines will
accumulate sediment and cause backup.

The drain line should be 2.0” O.D. copper pipe
or larger. Do not use plastic pipe for drain
lines. Consult factory.

DRAIN LINE - NHDI

WATER SUPPLY LINE - NHDI

1. Humidifier is intended to operate on Reverse
Osmosis (RO) water or De-ionized (DI) water
with a water conductivity of less than 20
Microsiemens.

2. Standard fill valves are sized for water
pressure ranging from 30 to 80 psig. For other
pressures, consult factory. This pressure
should be measured at the humidifier if the
water pressure is suspect.

3. ALWAYS supply and install a shut-off valve in
the fill water supply line dedicated to the
humidifier to facilitate servicing. Use ½" OD
plastic or stainless steel to within 4 feet of the
humidifier. Reduce plastic or stainless steel to
3/8" OD and connect to the factory-supplied
3/8" olive compression fitting under the
humidifier.

4. Same installation as #3, but add Drain Water
Cooler instead of fill.

DRAIN LINE - NHSC

1. Humidifier is equipped with a 1.5”" O.D.
unthreaded drain outlet on underside of drain
canal on bottom of the humidifier (see Figure

1. Humidifier is equipped with a 1.5” O.D.
un-threaded drain outlet on underside of drain
canal on bottom of the humidifier (see Figure
#6). A field-supplied funnel (see Figure #8) is
recommended. It will prevent backup in the
drain pan and in the cylinder due to partially
blocked or badly installed drain lines. This
prevents rusting of the drain pan.

2. The drain line should not end in a sink used
frequently by personnel, or where plumbing
codes prohibit it. If the Drain Water Cooler is
used with potable water then copper may be
used. Route to a floor drain or equivalent for
safety reasons, since drain water from
humidifier can be very hot. Verify with local
codes on DI and RO water. Drains should be
verified for their suitability for RO or DI water
and local codes should be checked.

3. Keep drain lines as short as possible. Keep

drain lines sloped down, not level and not
up since low spots in drain lines will
accumulate sediment and cause backup.

The drain line should be 2.0” O.D. S.S. pipe or
larger. Do not use plastic pipe for drain lines.
Consult factory.

-6-

l

A

Supply Water

t

Connection

3/8“

Drain

Water Cooler

Connection 3/8”

Drain

Connection

1.5" O.D.

Figure #11

Drain Line Connection

NHSC
Scale

Collector

Tank

A

7.95

B

(58.4)

Model
010-090
135-180 Left
135-180 Right

23.0

(20.2)

A (in.)

1.7”

1.7”

1.7”

Figure #12

Drain Connection

B (in.)

5.4”

5.4”

20.3”

Power
Inlet

Controls
Inlet

Optional
Cooling Ki
for SSR
(consult
factory)

STEAM LINE AND CONDENSATE RETURN LINE

1. Refer to the installation manual of the steam

distribution system used in your application.
Steam Distributor Form #XX-231, SAM-e
Form #XX-249, and Blower Pack Form
#XX-277.

ELECTRICAL

PRIMARY VOLTAGE SUPPLY WIRING TO
HUMIDIFIER

1. Check and ensure that available voltage and

phase corresponds with operating voltage and
phase of humidifier as indicated on the
humidifier spec label, see Figure #1.

2. Ensure that an adequate power supply is

available to carry full humidifier amperage
drawn as specified by rated amps on the
humidifier spec label, reference to local codes.

3. A dedicated external disconnect must be

installed. Do not exceed the maximum circuit
protection amps as indicated on the
nameplate label.

ir

Gap

Clamp and1.5”ID Hose
Factory Supplied

Install aCopper Funnelfor theNHSC mode
and aStainless SteelFunnel forthe NHDI
model (byothers).

4. Connect ground wire to cabinet ground clamp.

Do not use neutral wire of four wire supply as
ground.

5. Single phase humidifiers may be run on three

phase power, but load may unbalance power

NOTE: Steam hose should not
reach bottom of the funnel.

Install a2” O.DCopper Pipefor theNHSC
model and2”O.D. Stainless SteelPipe for
the NHDImodel(by others).

grid.

6. External wiring sizes must be in accordance

with NEC and/or CEC and existing local
electrical codes and by-laws.

Figure #13

Drain Pump by others (if necessary)

PRIMARY VOLTAGE SUPPLY WIRING FROM
HUMIDIFIER(S) TO BLOWER PACKS

1. All blower packs are wired (by others) to be

powered from the humidifier.

Humidifier

2. As a safety feature, blower packs come

equipped with a manual reset safety
thermostat and relay built into the blower pack
cabinet. The manual reset thermostat turns

Recommended Model
Gould - Model SSH
Consult Factory

Floor

Surface

Line

Drain Line

off the humidifier if the blower pack gets
overheated. The control thermostat, mounted
on the steam distributor, starts the fan when
steam is generated.

3. All blower packs have high efficiency blowers

to minimize the frontal and overhead
clearance required to absorb the steam.

-7-

(ACTUAL)

Figure #14

Primary Voltage Supply Wiring

PRIMARY (LINE) VOLTAGE WIRING TO UNITVOLTAGE

(BY OTHERS)

L1

L2

- Single Phase Unit.

- Single Phase Supply.

- Required Voltage Between L1 And L2.

- Load Balanced.

L1

L2

L3

Neutral

Ground

Ground

- Single Phase Unit.

- 3 Phase Supply.

- Required Voltage Between L1 And L2.

- Load Will Be Unbalanced.

Ground Wire

Dedicated

Disconnect

Ground Wire

Dedicated

Disconnect

Circuit

Breaker

Or

Circuit

Breaker

Or

Ground
Leg

2Pole
Te rm i na l
Block

E

I

X

N

T

T

Ground
Leg

2Pole
Te rm i na l
Block

E

I

X

N

T

T

Ground Wire

L1

L2

L3

Neutral

Ground

Dedicated

Circuit

Breaker

Or

Disconnect

- 3 Phase Unit.

- 3 Phase Supply.

- Required Voltage Between Any Two Legs.

- Load Will Be Balanced.

NOTE: VoltageAt TerminalBlock Must Be InAccordance With Spec. Label.
All Wiring ToBe InAccordance With Existing NationalAnd Local Electrical Codes.

-8-

Ground
Leg

3Pole
Te rm i na l

Block

E

I

X

N

T

T

4, All blower packs require field wiring between

two pole primary voltage terminal blocks and
two low voltage control (class 1 circuit wiring
required) terminal strips; one of each located
in the humidifier and the remote blower pack
cabinet. To properly access the primary block
on the humidifier, it is necessary to open the
side pan. To connect the primary and control
(class 1 circuit wiring required) wiring, the
wiring is fed through the grommet provided in
the bottom of the blower pack. The terminal
block and strip are accessed by removing the
blower pack cover.

5. Field wiring of remote blower packs must
conform to national and local electrical codes.
Refer to wiring diagram supplied inside the
humidifier.

6. Use approved wire for power connection from
two pole terminal block of remote blower pack
to additional two pole terminal block inside
electrical section of humidifier.

7. Use approved wire to connect the ground
clamp of remote mounted blower pack to
ground clamp provided in the electrical section
of humidifier.

LOW VOLTAGE CONTROL WIRING

A - Wall or Duct Mounted Control On/Off

Humidistat: Wired to make on drop in humidity, break

on rise to set-point. Set to desired % RH. Can be a
make/break set of contacts from a Building Automation
System.

B - Duct Mounted Safety High Limit On/Off

Humidistat (if used): Wired to make on drop in

humidity, break on rise to safety set-point. Set to
approximately 85% RH as a safety to help prevent
saturation and wetting in the duct.

C - Duct Mounted Safety Air-Proving On/Off

Switch (if used): Wired to make with sensed air flow,

break when no air flow. Used as a safety to prevent
saturation when there is no airflow.

1. NORTEC offers various versions of A, B and
C to suit each application. In general, A is
essential, whereas B and C are highly
recommended in ducted applications.

2. Field wiring from humidistat to humidifier and
between devices should be 18 AWG or
heavier and kept as short as possible.

3. Low voltage control terminal strips are
provided in the electrical compartment.
Internal sides are factory wired. External
sides are to be field wired.

On-Off Controls

Figure #15

External Wiring of On/Off Controls

A

B

C

D

External

Internal

10

8

Controls are available from NORTEC as
accessories. If controls were not ordered with
humidifier, they must be supplied by others. The
following information is relevant to all controls, factory
supplied or otherwise.

A, B, C and D (described below) are to be wired in
series (only one path for current) across terminals 8
and 10 on the low voltage control terminal strip or
replaced with a jumper wire for constant operation.
Caution: this is the “hot” wire from the 24V control
transformer; it will blow the 3A fuse if any control field
wiring touches ground.

4. Each humidifier is supplied with a wiring
diagram inside.

D - Blower pack safeties

CONTROL INSTALLATION

1. Mount any wall humidistat (control or high
limit) over standard electrical box at height
similar to typical thermostat. Any wall
humidistat should be in location
representative of overall space being
humidified and not in path of blower pack or
air supply grille. Do not mount on a outside
wall where temperature fluctuation can affect
control response.

2. Mount duct humidistat in location
representative of overall air humidity, usually
in the return duct. Do not mount it directly in
front of steam distributor or in turbulent or
mixing zone. Mount it where humidity and
temperature are uniform and representative of
spaces being humidified.

3. Mount duct high limit humidistat
downstream of steam distributors far enough
that, under normal humidity and air flow

-9-