Aprilaire 50 User Manual

FURNACE

BLOWER MOTOR

MODEL 50
CURRENT

SENSING RELAY

(IF REQUIRED)

24 VAC FURNACE

ACCESSORY TERMINALS

OR TRANSFORMER

(10VA MINIMUM)

SHUT-OFF

(SADDLE VALVE)

WATER SUPPLY

YELLOW

24V SOLENOID

VALVE WIRES

IMPORTANT

USE 120 VAC POWER SOURCE OTHER THAN FURNACE MOTOR
CIRCUIT. HOWEVER, THE TRANSFORMER CAN BE POWERED
OFF THE HOT 120 VAC LINE BEFORE IT ENTERS THE FURNACE.

• DO NOT WIRE TRANSFORMER INTO FURNACE BLOWER CIRCUIT.

IMPORTANT

WHEN MODEL 50 CURRENT SENSING RELAY IS USED:

• WIRE MODEL 50 CURRENT SENSING RELAY INTO
24 VAC HUMIDIFIER CONTROL CIRCUIT ONLY!

DO NOT INSTALL IN TRANSFORMER PRIMARY CIRCUIT.

CONNECT DRAIN LINE HERE

COMMON

HI

LO

YELLOW

WIRES

G

Y

W

C

R

THERMOSTAT

110 VAC

R

C

W

Y

G

FURNACE

OUTDOOR

TEMPERATURE

SENSOR FOR
AUTOMATIC

MODE

NORTH, EAST

OR WEST SIDE

OF HOME

ABOVE EXPECTED

SNOW LINE

CONTINUOUSLY POWERED

24 VAC TRANSFORMER

PROVIDED WITH HUMIDIFIER

CONNECT TO

HOT WATERSUPPLY

CONNECT DRAIN
LINE HERE

OUTPUTSINPUTSPOWER

GWCRHHODT GfA

ADHC TERMINAL STRIP

B

READ COMPLETE SAFETY INSTRUCTIONS AND INSTALLATION TEMPLATE BEFORE STARTING INSTALLATION

RETURN

SUPPLY

S

RETURN

SUPPLY

S

ATTENTION INSTALLER:

This product must be installed by a qualified heating and air conditioning contractor. Failure to do so could result in serious injury from electrical shock.

This product must be installed in compliance with all local, state and federal codes.

Proper humidification and humidity control also requires that the home be constructed in accordance with local codes and good building practices.

MODEL 500 SERIES HUMIDIFIER

WARNING

1. ELECTRICAL SHOCK HAZARD.

Disconnect electrical power to the
furnace before starting installation.
Failure to do so could result in
serious injury from electrical shock.

SHARP EDGES HAZARD. Sharp

2.
edges may cause serious injury from
cuts. Use care when making plenum
openings and handling ductwork.

RISK OF SCALDING. Water

3.
temperature over 125°F can cause
severe burns and scald instantly.
Shut off the hot water supply before
disconnecting or tapping into any
hot water supply line.

(SEE STEP 7 ON BACK AND “HUMIDIFIER CONTROL SAFETY AND INSTALLATION INSTRUCTIONS” FOR DETAILED WIRING INSTRUCTIONS)

Model 500

DIGITAL HUMIDIFIER
CONTROL

RESEARCH PRODUCTS CORPORATION • P.O. BOX 1467 • MADISON, WI 53701-1467 • CALL 800/334-6011 • FAX [phone]

RISK OF PROPERTY AND EQUIPMENT DAMAGE.

1. Do not install humidifier where freezing temperatures
could occur. The water line could freeze and crack
causing water damage to the home.

2. Do not install humidifier or bypass connection on the
furnace jacket.

3. Do not install humidifier or bypass connection on a
plenum face where the blanked off ends of the cooling
coil will restrict air movement through the humidifier.

4. Do not set humidity level above recommended or to
recommended level if condensation exists on inside
windows of any unheated space, as condensation
damage may result. Excess humidity can cause
moisture accumulation which can allow the possibility
for mold growth in the home.

CAUTION

5. Do not connect Model 500 or 500M transformer

6. When installing Humidifier Control on downflow

7. Do not install humidifier where water pressure

8. Do not install humidifier on systems with

Model 500M

MANUAL CONTROL

to blower motor wiring. Premature component
failure may result.

furnace, ensure blower continues to run after a
heat call is satisfied to eliminate hightemperatures
from damaging the Humidifier Control.

exceeds 125 psi, since damage to the humidifier
may result. Follow codes in effect concerning
pressure reduction.

greater than 0.4 in. wg pressure differential
between supply and return plenums.

90-120790-1510

SPECIFICATIONS

UMIDIFIER DIMENSIONS

H

Width (includingsolenoid valve): 155⁄8”

INSTALLATION OPTIONSRECOMMENDED WIRING DIAGRAMS

plenum of a forced air handling system and

(including drain spud): 13”

Height

Depth

: 10

1

⁄4”

BYPASS DUCT OPENING

6” diameter

PLENUM OPENING

91⁄2”W x 91⁄2”H

WATER FEED RATE

3 gph

ELECTRICAL DATA

24 VAC-60 Hz, 0.5 AMP

The Model 500 and 500M Aprilaire can be

installed on either the supply or return

is easily reversible for installation with

right hand or left hand bypass duct

connections. The humidifier dimensions

and serviceability must be considered
when selecting the best location for the
humidifier. Here are 2 examples of many

types of installations.

Upflow

Horizontal

90-1079

NOTE

When installing the Aprilaire humidifier
with the Aprilaire Digital Humidifier
Control or on a heat pump system, use
hot water. The heated water supplements
the reduced supply air temperature as
added heat for evaporation.

READ REVERSE SIDE FIRST! READ REVERSE SIDE FIRST!

12

10

2

7

9

6

11

1

4

3

5

8

– TOP –

READ COMPLETE SAFETY INSTRUCTIONS AND INSTALLATION TEMPLATE BEFORE STARTING INSTALLATION

FURNISHED ITEMS

uilt-in bypass damper

B

4 VAC Transformer

2

Digital HumidifierControl (Model 500 only)

Manual Humidifier Control (Model 500M only)

Humidifier Control Installation Instructions

Mounting screws (sheet metal screws)

odel 50 Current Sensing Relay (if required)

M

Saddle valve

umidifierInstallation Template

H

ITEMS NOT FURNISHED

Water supply line (1⁄4” copper)

Drain line (1⁄2” I.D. hose)

Low voltage wire

ypass ductwork

B

1. Press top & bottom tabs to remove

cover (1). Pull feed tube (3) out of
distribution tray (4). Remove Water Panel
Evaporator assembly. See Figure 1.

2. Humidifier is supplied with bypass

duct connection on left. For right side
bypass, swap location of drain spud (9)
and cap (10). Twist to remove spud
and cap.

3. Position template on supply or return

plenum. Make sure template is level.
Allow clearance for drain line and for
servicing. Trace template outline. Cut
9-1/2” x 9-1/2” opening. Avoid injury

from sharp edges.

1. Front Cover

2. Base

3. Feed Tube

4. Water Distribution Tray

5. Water Panel Evaporator

6. Scale Control Insert

7. Integral Damper

8. Damper Handle

9. Drain Spud

10. Hole Plug

11. Nameplate

12. Solenoid Valve

4. Place humidifier base (2) in

opening and secure with 6

®

screws in openings provided.

5. Select location for 6” collar

on opposite plenum to minimize
length and number of elbows in
bypass duct. Install 6” bypass
duct components. Attach duct to
humidifier collar using 2 screws
in openings provided.

6. Insert Water Panel Evaporator

assembly into base. Make sure
bottom of scale control insert (6)
is in drain spud. Snap top of
evaporator assembly into base.

PARTS LIST

Figure 1 Figure 2 Figure 3

90-1067 90-1068 90-1069

Insert feed tube into distribution
tray. See Figure 2. Rotate
nameplate (11) if necessary, so it
is right side up. Place point bypass
damper handle (8) to “WINTER”
(open) for heating season and
“SUMMER” for cooling season.

7. Control installation and wiring.

Disconnect electrical power to
furnace before wiring control.

In order for humidifier to operate,
furnace must be on and RH must
be below set-point of control.
Wiring diagrams illustrate
recommended method of
detecting furnace operation.

MANUAL HUMIDIFIER CONTROL,
MODEL 500M:

Manual Control can be mounted in return
duct or on wall in living space. Knob and
cover must be removed to mount control.
See wiring diagram for 24V control
connections.

• For return duct mounting, position
template at least 6” upstream of bypass
duct connection or humidifier. Avoid

injury from sharp edges when cutting
opening. Make sure foam gasket is in

place and secure control to duct using
2 screws in openings provided.

• For wall-mount, select location that will
not be affected by drafts or heat
sources. Remove and discard foam
gasket and secure control to wall over
wire access opening using screws &
anchors provided.

DIGITAL HUMIDIFIER CONTROL,
MODEL 500:

• Select location for control on return
duct at least 6” upstream of bypass duct
connection or humidifier. Drill 3/4” hole
for sensor. Knob and cover must be
removed to mount control. Place control
on duct with RH sensor extending into
duct opening. Make sure gasket is in
place around sensor cage. Secure
control to duct using 2 screws in
openings provided.

• See wiring diagrams on template and
control instructions for 24 V control
connections.

8. Humidifier will function with cold, hot,

softened or unsoftened water. Hot water
(140°F max) is strongly recommended to
provide maximum evaporative capacity.
Saddle valve provided may be used to tap
into water supply. See installation
instructions on saddle valve package.
Saddle valve is designed to be fully opened
or closed. Do not use to regulate flow.

9. Run 1/4” copper tubing from saddle

valve to solenoid valve. DOUBLE-WRENCH
TO PREVENT LEAKING. See Figure 3.

10. INSTALL DRAIN IN ACCORDANCE

WITH LOCAL CODES. Run 1/2” I.D. hose

from drain spud to floor drain. Make sure
drain has constant downward slope and is
not kinked. Do not over-tighten hose clamp
onto drain spud. Do not use solvent
adhesive on drain spud.

11. Check humidifier operation. Open

saddle valve and turn control to highest
setting. Turn on furnace. Allow humidifier
to run until water flows from drain. Make
sure all electrical connections are secure
and all plumbing connections are water­tight. Set control to proper setting.

NOTE: BEFORE LEAVING THE
JOB SITE, MAKE SURE:

1. Saddle valve is fully open.

2. All plumbing connections are
watertight.

3. Humidifier functions properly.

4. Bypass damper is in proper
position.

90-1250

TEMPLATE MU ST BE LEVEL

IMPORTANT! Be sure owner’s manual containing instructions for

operation and warranty information is given to owner in order to avoid

unnecessary calls. Warranty is void unless humidifier is installed by qualified

heatingand air conditioning contractor due to possible misapplication of product.

10008974 B2205116A 4.10