Specifications

24 VAC FURNACE
ACCESSORY TERMINALS
OR TRANSFORMER
(10 VA MINIMUM)
HI
C
LO
YELLOW 24 V
SOLENOID
VALVE WIRES
FURNACE
BLOWER MOTOR
MODEL 50
CURRENT SENSING RELAY
(IF REQUIRED)
HUMIDISTAT
WATER SUPPLY
SHUT-OFF
(SADDLE VALVE)
CONNECT DRAIN LINE HERE
READ COMPLETE SAFETY INSTRUCTIONS AND INSTALLATION TEMPLATE BEFORE STARTING
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.
ATTENTION INSTALLER:
HUMIDIFIER MODEL 500
The Model 500 Aprilaire can be
installed on either the supply or return
plenum of a forced air handling
system and 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.
P.O. BOX 1467 • MADISON, WI 53701-1467 • CALL 800/334-6011 • FAX [phone]
RETURN
RETURN
RETURN
SUPPLY
SUPPLY
SUPPLY
RETURN
RETURN
RETURN
SUPPLY
SUPPLY
SUPPLY
Horizontal
Upflow
NOTE: SOME FURNACES ARE EQUIPPED WITH ACCESSORY TERMINALS THA
T CAN BE USED FOR THE HUMIDIST
A
T
. THE RP MODEL 50 CURRENT SENSING
RELA
Y (NOT FURNISHED) MA
Y NOT BE NECESSARY IN THIS CASE. CONSUL
T THE FURNACE MANUF
ACTURER’S RECOMMENDATIONS FOR WIRING.
IMPORTANT
WHEN MODEL 50 CURRENT
SENSING RELAY IS USED:
• WIRE MODEL 50 CURRENT
SENSING RELA
Y INTO 24
V
AC HUMIDIFIER CONTROL
CIRCUIT ONL
Y!
DO NOT
INST
ALL IN TRANSFORMER
PRIMAR
Y CIRCUIT.
IMPORT
ANT
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.
90-1066
90-1079
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.
2.
SHARP EDGES HAZARD. Sharp
edges may cause serious injury from
cuts. Use care when making plenum
openings and handling ductwork.
3.
RISK OF SCALDING. Water
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.
SPECIFICATIONS
HUMIDIFIER DIMENSIONS
Width (including solenoid valve): 15
5
⁄8”
Height
(including drain spud): 13”
Depth
: 10
1
⁄4”
BYPASS DUCT OPENING
6” diameter
PLENUM OPENING
9
1
⁄2”W x 9
1
⁄2”H
WATER FEED RATE
3 gph
ELECTRICAL DATA
24 VAC-60 Hz, 0.5 AMP
CAUTION
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.
5. Do not connect Model 500 transformer to
blower motor wiring. Premature component
failure may result.
6. When installing Humidistat on downflow
furnace, ensure blower continues to run after
a heat call is satisfied to eliminate high
temperatures from damaging the Humidistat.
7. Do not install humidifier where water pressure
exceeds 125 psi, since damage to the
humidifier may result. Follow codes in effect
concerning pressure reduction.
8. Do not install humidifier on systems with
greater than 0.4 in. wg pressure differential
between supply and return plenums.
RISK OF PROPERTY AND EQUIPMENT DAMAGE.
INSTALLATION OPTIONSWIRING DIAGRAM