The p/n 903091 2-wire and p/n 902987 A/C
Heat Pump (4 to 7 wire) Relay Boxes install with
current models of the E2 and current models of
the E(1,2) NORDYNE electric furnaces respec-
tively. The 2-wire Relay Box has control switches
that are operable through an opening in the
furnace door, where applicable.
Important Information
Read all instructions carefully before starting
the installation. Specifications or designs are
subject to change or to discontinuance without
notice and without incurring obligations.
!
WARNING:
Improper installation may damage
equipment, can create a hazard, and
will void the warranty.
Installation Instructions
2 Wire: For models E2E(H,B) Series
4-7 Wire: For models E(1,2)EH Series
Electric Furnace - Relay
!
DANGER:
Shut off electrical supply to the fur-
nace at the household breaker box to
prevent electrical shock which could
cause personal injury.
These instructions are primarily intended to
assist qualified individuals experienced in the
proper installation of heating and/or air condi-
tioning appliances. Some local codes require
licensed installation/service personnel for this
type of equipment. Read all instructions care-
fully before starting the installation.
2
Circuit
Breakers
Relay Box
Wiring Harness
plugs here on
Furnace Control
Panel
Blower
and
Relay
Decorative
Door Insert
Door Control
Frame (used w/
2 wire relay box)
Furnace
Door
Wiring
Harness
Low Voltage
Wiring
Blower
Connector
Connects
Here
Connect
8 Pin
Connector
on Wiring
Harness
Here
Blower
Connector
(Connect to
Relay Box)
Wiring Harness
Connect
to Relay
Box
Connect
to Furnace
Control Panel
Figure 1. E1E(-) Series Electric Furnace
Circuit
Breakers
Relay Box
Wiring Harness
plugs here on
Furnace Control
Panel
Blower
and
Relay
Furnace
Door
Wiring
Harness
Low Voltage
Wiring
Figure 2. E2E(-) Series Electric Furnace, manufactured prior to 1999
Figure 2a. E2E(-) Series Electric Furnace, manufactured 1999 or later
Connect Blower
Connector Here
Blower Connector
(Connect to Relay Box)
Circuit
Breakers
Relay Box
Wiring Harness
plugs here on
Furnace Control
Panel
Blower
and
Relay
Nameplate
Insert
Door Control
Frame (used w/
2 wire relay box)
Furnace
Door
Wiring
Harness
Low Voltage
Wiring
Connect 8 Pin
Connector on
Wiring Harness
Here
Connect Blower
Connector Here
Blower Connector
(Connect to Relay Box)
Connect 8 Pin
Connector on
Wiring Harness
Here
3
Installation Sequence for Models
E(1,2) E(H,B) Series Electric
Furnace (See Figure 1, 2, or 2a)
Prior to installing a relay box in the NORDYNE
furnace, be sure to install the correct A/C sys-
tem equipment as outlined on the furnace op-
tions label.
Remove the furnace door by pulling outward
either from the top or the top side of the door.
Switch the circuit breaker(s) to the OFF posi-
tion. (See Figure 1, 2, or 2a for the circuit
breaker location.)
Before installing the relay box remove the blower
and install the cabinet insulation kit for furnaces
that are not factory equipped with this package.
Refer to the instructions supplied with the kit for
proper installation.
E(1,2)EH Models: All E(1,2)EH models require
a relay box when adding an air conditioner or
heat pump.
E2EB Models: E2EB models using a 2-wire
thermostat require a relay box (2-wire) when
adding an air conditioner.
Blower Selection: See the furnace Installation
Instructions for the correct air conditioning or
heat pump available with the factory installed
furnace blower. Change out the blower when
needed.
Remove the cover from the relay box by remov-
ing the screw from each side.
Blower Speed Selection:
• HEATING - Move the orange wire on the
circuit board to one of the four quick-connects
labeled with heating blower speeds.
• COOLING - Move the violet wire on the circuit
board to one of the three quick-connects
labeled with cooling blower speeds.
• TWO SPEED BLOWER - Connect the or-
ange wire (heating) to the L (low) quick-
connect for low speed. Connect the violet
wire (cooling) to the ML (medium low) quick-
connect for high speed.
• THREE OR FOUR SPEED BLOWER - See
Table 1 for the appropriate speed connec-
tions for the E1E(-) and Table 2 for the E2E(-).
Reattach the relay box cover using the two
screws previously removed.
IMPORTANT: For the 2-wire relay box (only
after the cover has been reattached):
a. Attach two red caps (provided in plastic
bag) to the switches that stick through the
bezel on the sheet metal cover (see Figure
3, items 7 and 8).
b.
E1 and E2 furnace models manufactured
prior to 1999 only:
Attach the appropriate
brand label to the sheet metal cover so that
it may be seen through the door control
frame (see Figure 2) in the furnace door
when it is replaced.
c.
E1 and E2 furnace models manufactured
prior to 1999 only:
Attach the foam “stand-
off” to the bottom corner on the back side
Furnace Operation (orange wire)
Furnace Model # -010, 012
-015, -017,
-020, -023
Relay Box Speed
Terminal (min.)
LML
Air Conditioning/Heat Pump Operation (violet wire)
Air Conditioning Model # -024 -030, -036
-042, -046,
-048
Heat Pump Model # -018 -024, 030
-036, -042,
-048
Relay Box Speed
Terminal (min.)
ML MH H
Note: See furnace installation instruc-
tions for nominal air deliveries.
Table 1. E1E(-) Heating and Cooling Speed Setting Positions – 4 Speed Blower
Table 2. E2E(-) Heating and Cooling Speed Setting Positions – 3 or 4 Speed Blower
Air Conditioning/Heat Pump Operation (violet wire)
SEE FURNACE BLOWER LABEL OR FURNACE
INSTALLATION INSTRUCTIONS FOR
APPROPRIATE SPEED CONNECTIONS
Note: See furnace installation instructions
for nominal air deliveries.
Furnace Operation (orange wire)
Furnace Model #
Relay Box Speed
Terminal (min.)
L-3 spd ML-4 spd
-010, -012, -015,
-017, -020, -023
4
of the relay box opposite the side where the
bracket is attached (See Figure 2b). This
standoff will prevent movement of the relay
box when the homeowner adjusts the
switches.
Relay Box Attachment
(See Figure 1, 2, or 2a)
Attach the mounting bracket to the appropriate
side of the relay box. Attach the relay box to the
side of the blower housing. For E2 furnaces
manufactured 1999 or later, bracket should be
attached by self tapping 2 screws into the side
of the blower housing approximately 1/2” back
from the mounting holes.
Insert the relay/blower assembly into the fur-
nace by sliding it into the furnace and under the
mounting tabs. Secure the blower in place by
using the blower screws previously removed.
Relay Box Connection (See Figure 1, 2, or 2a):
• Unplug the blower connector and the thermo-
stat pigtail leads connector from the furnace
control panel.
• Plug the two different 6-circuit connectors on
the relay box wiring harness into their corre-
sponding locations on the furnace control
panel (where the blower and thermostat leads
connectors were just removed).
• Plug the 8-circuit connector on the other end of
the wiring harness into the side of the relay box.
• Plug the 6-circuit blower connector into the
bottom of the relay box.
Low Voltage Wiring
(See Figure 1, 2, or 2a)
Bring in the low voltage field wires from the
thermostat and air conditioning or heat pump
unit and attach them to the screw terminals
located at the top of the relay box. See Figure 5
for System Wiring.
Switch the circuit breaker(s) to the ON position.
The unit is now ready for operation.
SYSTEM OPERATION
For the AC/Heat Pump Relay Box
Heating: Set the furnace system switch to
AUTO (where applicable), the thermostat sys-
tem switch to HEAT, and the thermostat fan
switch to AUTO.
Cooling: Set the furnace system switch to
AUTO (where applicable), the thermostat sys-
tem switch to COOL, and the thermostat fan
switch to AUTO.
Emergency Heat: (Used with a heat pump
only.) Set the furnace system switch to AUTO
(where applicable), the thermostat system switch
to EMERGENCY HEAT, and the thermostat fan
switch to AUTO.
Continuous Air Circulation: Set the thermo-
stat fan switch to ON.
Shut off System: Set the thermostat system
switch to OFF and set it to the lowest tempera-
ture setting. Set the furnace system switch to
OFF and shut off all power to the air conditioner.
For the 2-Wire Relay Box
Heating: Set the furnace system switch to
AUTO (where applicable), the temperature
switch (on the relay box) to HEAT, and the fan
switch (on the relay box) to AUTO.
Cooling: Set the furnace system switch to
AUTO (where applicable), the temperature
switch (on the relay box) to COOL, and the fan
switch (on the relay box) to AUTO.
Continuous Air Circulation: Set the fan switch
(on the relay box) to ON.
Shut off System: Set the temperature switch
(on the relay box) to OFF and set the thermostat
to the lowest temperature setting. Set the
furnace system switch to OFF and shut off all
power to the air conditioner.
Attach foam "standoff" here
Figure 2b. E2E(-) (Pre-1999 manufacture)
Electric Furnace w/2 wire Relay Box
5
Blower and Relay Replacement Parts List
1
2
3
4
6
7
8
1
2
3
4
5
6
Figure 3. 2 Wire Relay Box, Exploded View
Figure 3. A/C Heat Pump Relay Box, Exploded View
Model p/n 903091
Model p/n 902987
ITEM
# PART # DESCRIPTION 903091 902987
1 375952 Cover (2 Wire) 1
376431 Cover (AC/HP) 1
2 378700 Box, Relay 1 1
3 624567 2 Wire Relay Circuit Board 1
624625 AC/HP Relay Circuit Board 1
4 259200 Wire Harness 1 1
5 376050 Mounting Bracket, E1 - 1
6 380790 Mounting Bracket, E2 1 1
7 669084 Bezel 1 -
8 632278 Switch Cap 2 -
6
Figure 5. System Wiring
Blower
Motor
L
ML
MH
H
C
123 456
123 456
R Y W G
A/C O.D. Section
4 Wire A/C
T- Stat
8 765
4
3
21
8 765
4 3
21
Blower
Motor
R C Y O W
2
W/E G
L
ML
MH
H
C
Furnace With the AC/Heat Pump
Relay Box and a 4 Wire Thermostat
123 456
123 456
RC RH Y W G
A/C O.D. Section 5 Wire A/C
T- Stat
8 765
4
3 21
Blower
Motor
R C Y O W 2 W/E G
L
ML
MH
H
C
Furnace With the AC/Heat Pump
Relay Box and a 5 Wire Thermostat
123 456
123 456
R W
A/C O.D. Section
2 Wire Heat
Only T-Stat
8 765
4 3
21
8 765
4 3
21
Y R C W
Furnace With the 2 Wire Relay
Box and a 2 Wire Thermostat
HEAT
COOL
OFF
ON
AUTO
FAN
123 456
123 456
H/P O.D. Section
H/P
T- Stat
Blower
Motor
R C Y O W2 W/E G
L
ML
MH
H
C
Furnace With the AC/Heat Pump
Relay Box and a Heat Pump
R C Y O E W2
R C Y O W2 E G
123 456
123 456
Powermiser
Compressor Section
Blower
Motor
R C Y O W2 W/E G
L
ML
MH
H
C
Furnace With the AC/Heat Pump Relay Box and a Powermiser
C W2 G R G Y W2 O P R
Powermiser
T- Stat
C W1 G Y E F O P R X
Fan Coil T-Stat
ODT
LEGEND
Field Wiring
Factory Wiring
Wire Harness Supplied with Relay Box
Wire Harness Supplied
with Relay Box
Wire Harness Supplied
with Relay Box
Wire Harness Supplied
with Relay Box
Wire Harness Supplied with Relay Box
Optional
Heat Pump
Interconnect
Cable
8 765
4
3 21
8 765
4
3 21
8 765
4
3 21
8 765
4
3 21
8 765
4
3 21
3
2
1
6
5
4
3
2
1
6
5
4
6
5
4
3
2
1
6
5
4
3
2
1
Furnace
control panel
1: SEQ1 (W2)
2: SEQ2 (W2)
3: 24V COM
4: 24V HOT
5: G
6: OPEN
240V L2
240V L1
HIGH
MED-HIGH
MED-LOW
LOW
3
2
1
6
5
4
3
2
1
6
5
4
6
5
4
3
2
1
6
5
4
3
2
1
Furnace
control panel
1: SEQ1 (W2)
2: SEQ2 (W2)
3: 24V COM
4: 24V HOT
5: G
6: OPEN
240V L2
240V L1
HIGH
MED-HIGH
MED-LOW
LOW
3
2
1
6
5
4
3
2
1
6
5
4
6
5
4
3
2
1
6
5
4
3
2
1
Furnace
control panel
1: SEQ1 (W2)
2: SEQ2 (W2)
3: 24V COM
4: 24V HOT
5: G
6: OPEN
240V L2
240V L1
HIGH
MED-HIGH
MED-LOW
LOW
3
2
1
6
5
4
3
2
1
6
5
4
6
5
4
3
2
1
6
5
4
3
2
1
Furnace
control panel
1: SEQ1 (W2)
2: SEQ2 (W2)
3: 24V COM
4: 24V HOT
5: G
6: OPEN
240V L2
240V L1
HIGH
MED-HIGH
MED-LOW
LOW
3
2
1
6
5
4
3
2
1
6
5
4
6
5
4
3
2
1
6
5
4
3
2
1
Furnace
control panel
1: SEQ1 (W2)
2: SEQ2 (W2)
3: 24V COM
4: 24V HOT
5: G
6: OPEN
240V L2
240V L1
HIGH
MED-HIGH
MED-LOW
LOW
7
Figure 6. Wiring Schematics
P1
H(H)* MH(M)* ML(L)* L
COOL
HEAT
K1
K2
P2
K3
K3
K4
COOL
OFF
HEAT
AUTO
FAN ON
K1
Cooling Speed
Selector (violet wire)
Heating Speed
Selector
(orange wire)
K2
K4
Blower
Switch
Temperature
Switch
2 Wire Circuit Board (used in relay box 903091)
AC/Heat Pump Circuit Board (used in relay box 902987)
P2
K1
K2
P1
COOL
HEAT
K1
K2
Cooling Speed
Selector (violet wire)
Heating Speed
Selector
(orange wire)
6 5 4 3 2 1
6 5 4 3 2 1
6
5
4
3
2
1
7
8
6
5
4
3
2
1
7
8
YR C W
R C Y O W2 W/E G
* - 3 speed motor
* - 3 speed motor
H(H)* MH(M)* ML(L)* L
O’Fallon, MO
7088020 (Replaces 708136A)
Specifications and illustrations subject to change without
notice and without incurring obligations. Printed in
U.S.A. (08/07)
¢708802®¤
7088020
/
