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035-17438-001 Rev. A (901)

18

Unitary Products Group

ACCESSORY CONNECTIONS

The furnace control will allow power switching control of vari-
ous accessories. Refer to Figure 14 for connection details.

Electronic Air Cleaner Connection

Two 1/4” spade terminals (EAC and EAC N) for electronic air
cleaner connections are located on the control board. The
terminals provide 115 VAC (1.0 amp maximum) during circu-
lating blower operation. These terminals are energized in
continuous fan mode only if the green wire labeled “G Cool
Speed” is connected as described below. A high voltage con-
nection lead is routed to the junction box for easy connection.

Humidifier Connection

Two 1/4” spade terminals (HUM and HUM N) for humidifier
connections are located on the control board. The terminals
provide 115 VAC (1.0 amp maximum) during heating system
operation. A high voltage connection lead is routed to the
junction box for easy connection.

OPERATION AND MAINTENANCE

SEQUENCE OF OPERATION

The following describes the sequence of operation of the fur-
nace as it relates to a furnace equipped with a variable speed
blower. Refer to the schematic wiring diagram on page 26 for
component location. 

CONTINUOUS BLOWER

There are two modes of continuous blower operation. In one
mode the blower is controlled directly through the blower
motor. In the second mode the blower is controlled through
the ignition control. In the first mode, when the thermostat
fan-switch is set to the ON position a circuit is completed
between terminals “R” and “G” of the thermostat. The contin-
uous fan speed will be 63% of the high cool speed. If more air
is desirable the green wire labeled (G Cool Speed) may be
connected to the “G” terminal of the ignition control to achieve
HIGH COOL speed (DIP switch number 3 on the ignition con-
trol must be in the OFF position).

Intermittent Blower Cooling

On cooling/heating thermostats with fan switch, when the fan
switch is set in the auto position and the thermostat calls for
cooling, a circuit is completed between the R, Y and G termi-
nals. The motor is energized through the Y1 cool terminal
and runs on the speed selected on the CFM / Timer board.
The fan off setting is fixed at 60 seconds for SEER enhance-
ment.

HEATING OPERATIONAL SEQUENCE

Two Stage Thermostat

The ignition control in this furnace is unique to this product.
The control allows for a 24 volt or a 115 volt circulator input/
output. This allows for the replacement of the variable speed
motor with a multi-speed PSC motor in the event a variable
speed motor is not available at the time of servicing.

In a typical system, a call for first stage heat is initiated by
closing the W1 thermostat contacts. The inducer blower is
energized at high speed and the control waits for the low
pressure switch contacts to close. The inducer blower is
energized at low speed and the 120 VAC silicon carbide igni-
tor is powered.

At the end of the ignitor warmup time, the first stage of the
two stage gas valve is energized (low fire). Flame must be
detected within 7 seconds. If flame is detected, the delay-to-
fan-on period begins. After the delay-to-fan-on period ends,
the circulator fan is energized at low heat speed and the air
cleaner and humidifier are energized.

A call for second stage heat (W1 and W2) after a call for first
stage heat will energize the inducer at high speed and ener-
gize the circulator at high heat speed. The circulator will ener-
gize at high heat speed after 30 seconds with a call for
second stage heat. If the furnace has been operating in first
stage heat for more than 30 seconds and the control receives
a call for second stage heat, the blower will immediately
switch to high speed. The second stage pressure switch con-
tacts will close and energize the second stage gas valve (high
fire).

If a call for second stage heat occurs at the same time as a
call for first stage heat, the second stage heat is energized
immediately after flame rectification is sensed on fist stage.

When the second stage of the thermostat is satisfied, the
inducer motor is reduced to low speed and the 2nd stage gas
valve is de-energized to 1st stage. The circulator remains on
high heat speed for 30 seconds then de-energizes to low
heat speed.

 FIGURE 14 : 

Accessory Connections

115 VOLT
HUMIDIFIER

115 VOLT
ELECTRONIC
AIR CLEANER

BLK

WHT

EAC HOT

HUM. HOT

BLK

WHT

EAC

HUM

EAC

HUM

NEUTRALS

SWITCHED
CIRCUITS

Label all wires prior to disconnecting when servicing
controls. Wiring errors can cause improper and dan-
gerous operation. Verify proper operation after ser-
vicing.

Содержание PxDUA12V06401 series

Страница 1: ...035 17438 001 Rev A 901 EFFICIENCY RATING CERTIFIED CAUTION READ ALL SAFETY GUIDES BEFORE YOU START TO INSTALL YOUR FURNACE SAVE THIS MANUAL TABLE OF CONTENTS GENERAL INFORMATION 2 UNIT INSTALLATION 3...

Страница 2: ...PRODUCT COULD CAUSE PERSONAL INJURY OR PROPERTY DAMAGE IMPROPER INSTALLATION ADJUSTMENT ALTERATION SERVICE OR MAINTENANCE CAN CAUSE INJURY OR PROPERTY DAMAGE REFER TO THIS MANUAL FOR ASSISTANCE OR AD...

Страница 3: ...ptable heat loss calculation for the structure ACCA Manual J or other approved methods may be used The furnace should be located using these guidelines 1 Where a minimum amount of vent piping and elbo...

Страница 4: ...the total input rating of all equipment located in the enclosure b Not less than the sum of the areas of all vent con nectors in the confined space 3 Louvers Grilles and Screens a In calculating free...

Страница 5: ...nds in a general vertical direction and does not con tain offsets exceeding 45 degrees except that a vent system having not more than one 60 degree offset is permitted NOTE This appliance may be commo...

Страница 6: ...nce being operated in operation Adjust thermostat so appli ance will operate continuously 5 Test for draft hood equipped appliance spillage at the draft hood relief opening after 5 minutes of main bur...

Страница 7: ...V UH INPUT MBH H L OUTPUT MBH H L NOM CFM CABINET WIDTH IN AFUE1 LOW FIRE TEMP RISE F HIGH FIRE TEMP RISE MAX OUTLE AIR TEMP F BLOWER TOTAL UNIT AMPS MAX OVER CURRENT PROPECT2 MIN WIRE SIZE AWG 75 FT...

Страница 8: ...removable access panel is recommended in the outlet duct such that smoke or reflected light would be observable inside the casing to indi cate the presence of leaks in the heat exchanger This access...

Страница 9: ...and notes on blower perfor mance tables in this manual Where the return duct system is not complete the return con nection must run full size to a location outside the utility room or basement For fur...

Страница 10: ...s is recommended Refer to Fig ure 6 on page 10 NOTE See crawl space installation for suspending the fur nace in attic installations CRAWL SPACE INSTALLATION The furnace can be hung from floor hoists o...

Страница 11: ...cordance with instructions Specific electrical data is given on the furnace rating plate Provide a power supply separate from all other circuits Install overcurrent protection and disconnect switch pe...

Страница 12: ...OFF position and the main electrical source disconnected complete the low voltage wiring from the ther mostat to the terminal board on the CFM programmable board Connect Class 2 control wiring see Fig...

Страница 13: ...nt 1 Blockage of internal flue gas passage ways 2 Blockage of vent piping 3 Failure of combustion air blower motor Limit Control The high temperature limit control is located on the furnace vestibule...

Страница 14: ...increment find the cubic feet of gas consumed per hour from Table 4 on page 15 NOTE To find the Btuh input multiply the number of cubic feet of gas consumed per hour by the BTU content of the gas in y...

Страница 15: ...cement The temperature rise or temperature difference between the return air and the heated air from the furnace must be within the range shown on the furnace rating plate Application limi tations are...

Страница 16: ...uction for the recommended airflow and Table 6 on page 17 The DELAY Tap should be set in the B position for a two stage condenser This results in a 45 second off delay at 82 of the programmed cooling...

Страница 17: ...002UHC11 L8V1002UHC11 P DUC20V09601 G8V12020UHC11 L8V12020UHC11 COOL TAP ADJ TAP High Low High Low High Low High Low 1340 740 1675 920 2050 1135 2020 1130 A B 1155 635 1555 850 1860 980 1855 960 B B 1...

Страница 18: ...is fixed at 60 seconds for SEER enhance ment HEATING OPERATIONAL SEQUENCE Two Stage Thermostat The ignition control in this furnace is unique to this product The control allows for a 24 volt or a 115...

Страница 19: ...gas valve When power is restored the gas valve will remain deener gized and a restart of the ignition sequence will begin imme diately A momentary loss of gas supply flame blowout or a shorted or open...

Страница 20: ...LOW INDUCER LOW STAGE PRESSURE SWITCH HSI 1ST STAGE MAIN VALVE FLAME SENSE LOW CIRCULATOR HEAT SPEED 1ST STAGE LOW PRESSURE SWITCH CLOSE RECOGNITION HSI WARM UP 17 SEC IGNITION ACTIVATION PERIOD 4 SE...

Страница 21: ...bly for cleaning is as follows 1 Disconnect the power supplied to the furnace 2 Remove the vest and blower panels 3 Disconnect the motor control harness and the power har ness from the motor 4 Remove...

Страница 22: ...including the flue baffle plate rear may be vacuumed or cleaned with hot water if necessary 6 The upper portion of the heat exchanger is now accessi ble With a long flexible wire brush clean inside ea...

Страница 23: ...R REMOVAL FOR CONTROLLER REPLACEMENT Refer to BLOWER CARE on page 21 of this manual for blower removal instructions Rest the blower on its side so the end of the motor is accessible and facing up Wait...

Страница 24: ...ehind a clear view port in the blower compartment door DO NOT remove the furnace blower compartment panel OR turn off furnace power as either action will clear the control s memory of the fault The co...

Страница 25: ...y low gas pressure faulty gas valve faulty hot surface ignitor reversed line polarity or burner problem 8 FLASH This fault is indicated if the flame is lost 5 times during the heating cycle This could...

Страница 26: ...NTROL BOARD P3 S3 2 PIN PLUG SOCKET AT HOT SURFACE IGNITOR P4 S4 3 PIN PLUG SOCKET AT INDUCER MOTOR P5 S5 3 PIN PLUG SOCKET ON VALVE P6 S6 6 PIN PLUG SOCKET ON CFM TIMER BOARD P7 S7 16 PIN PLUG SOCKET...

Страница 27: ...035 17438 001 Rev A 901 Unitary Products Group 27 SERVICE RECORDS...

Страница 28: ...hange without notice Printed in U S A 035 17438 001 Rev A 901 Copyright by York International Corp 2001 All rights reserved Supersedes 035 17438 001 Rev A 801 Unitary 5005 Norman Product York OK Group...

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