Lennox ECB27 Series User manual

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THIS MANUAL MUST BE LEFT WITH THE
HOMEOWNER FOR FUTURE REFERENCE
WARNING
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, personal
injury or loss of life. Installation and service must be
performed by a licensed professional HVAC installer or
equivalent, service agency, or the gas supplier.
CAUTION
As with any mechanical equipment, contact with sharp
sheet metal edges can result in personal injury. Take
care while handling this equipment and wear gloves and
protective clothing.
Shipping and Packing List
Package 1 of 1 contains:
1 – Assembled electric heat section
1 – Bag assembly containing the following:
6 – Screws
1 – Wiring diagram
Circuit breaker cover - 1 each
1 – Transformer (575V, 3-phase, 60Hz only)
1 – Fuse block extension plate (460V, 3-phase, 60Hz and
575V, 3-phase, 60Hz only)
2 – Adhesive-backed foam seals
1 – Circuit breaker cover
Check equipment for shipping damage; if found, immedi-
ately contact the last carrier.
INSTALLATION
INSTRUCTIONS
ELECTRIC HEAT SECTIONS
507855-01
7/2019
ECB27 Series Units
WARNING
Electric shock hazard! - Disconnect all power
supplies before servicing.
Replace all parts and panels before
operating.
Failure to do so can result in death or
electrical shock.
Electric Heat Section
The ECB27 series electric heat section provides eld-in-
stalled electric heat for various air handler units. These
electric heat sections are available in either single- or
three-phase. Single-phase heat sections are equipped
with either terminal blocks or circuit breakers.
Refer to the model-specic air handler product specica-
tion bulletin for heat section applications.
General Information
These instructions are a general guide and do not su-
persede local codes. Local authorities having jurisdiction
should be consulted before installation. Read these in-
structions thoroughly before starting installation.
Be sure to disconnect all power to the unit before you in-
stall and service this equipment. Use proper tools and pro-
tective equipment during installation and service.
Installation of air handler with or without optional electric
heat must conform with standards in the National Fire
Protection Association (NFPA) Standard for Installation of
Air Conditioning and Ventilation Systems NFPA No. 90A,
and Standard for Installation of Resident Type Warm Air
Heating and Air Conditioning System, No. 90B, the man-
ufacturer’s installation instructions, and local municipal
building codes.

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Heat Section Installation
Before installing the electric heat section, check the unit
rating plate to ensure that the unit meets the job require-
ments, that proper electrical power is available, and that
proper duct clearances are maintained.
KNOCK OUT EXTENDED WIDTH WHEN USING
20KW OR 25KW ELECTRIC HEAT
FIGURE 1. Air Handler Electric Heat Knockouts
NOTE – It is easier to install the electric heat section in-
side the air handler unit before the unit is set and the ple-
num is attached.
1 - Shut o󰀨 all power to the air handler. More than one
disconnect may be required.
2 - Remove air handler access panel.
3 - Remove the electric heat knockout from the air
handler vestibule panel to accommodate the heater
being used. Remove the extended width knockout
to allow for installation of 20kW or 25kW heater (see
gure 1).
4 - Slide the electric heat section into the air handler.
Be careful that the heating elements do not rub
against the sheet metal opening when they slide
into the air handler. The hole(s) on each side of the
heater line up with holes in the air handler control
box. Secure the electric heater into place with the
screws that are provided in the bag assembly.
Cabinet Modications for 460 Volt, 3 Ton Models
Modications are necessary when an ECB27-10F-G /
15F-G voltage (460 volt) electric heat section is installed
in a 460 volt, 3 ton air handler (see gure 2).
ISSUE:
SOLUTION:
Remove the tabs identified below.
Tabs restricting electric
heat section installation.
Tabs on a 460 volt, 3 ton air handler prevent proper installation of the ECB27-10F-G / 15F-G voltage (460 volt)
electric heat section.
FIGURE 2. Cabinet Modications
WARNING
Electric Shock Hazard. Can cause injury or
death. Unit must be properly grounded in
accordance with national and local codes.
Line voltage is present at all components
when unit is not in operation on units with
single-pole contactors. Disconnect all remote
electric power supplies before opening
access panel. Unit may have multiple power
supplies.
Circuit Breaker Installation
1 - Install the circuit breaker on the air handler deck
ange. Use the provided six screws to secure the
circuit breaker (see gure 3).
NOTE – When applied in the downow position, the cir-
cuit breakers must be rotated to the UP position. See
gure 3 and follow the procedure below:
A - Disconnect power to the unit if present.
B - Remove the screw and slide the breakers o󰀨 the
mounting rail.
NOTE – You may need to remove the wire tie closest to
the circuit breaker to allow rotation.

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C - Rotate the circuit breaker 180 degrees.
D - Slide the circuit breaker back on the rail and secure
in place with previously removed screw.
2 - The air handler access panels are factory supplied.
There is a patch plate over the circuit breaker
opening. Remove the circuit breaker patch plate
from the air handler access panel. See gure 4.
3 - Replace the air handler access door.
4 - Choose the appropriately sized adhesive-backed
circuit breaker seal and remove any perforated
sections (if needed). Apply the seal to the outside of
the air handler access panel so that the seal is snug
around the circuit breakers.
5 - Break the patch plate for the specic size of electric
heat section that you are installing. Discard the
unused piece of patch plate (see gures 5 and 6).
6 - Secure the patch plate on the air handler access
door.
IN DOWNFLOW APPLICATIONS, CIRCUIT BREAKERS
MUST BE ROTATED 180º TO THE UP POSITION.
REMOVE THE SCREW AND SLIDE THE
TATE BREAKERS 180º AND SLIDE BACK
ON RAIL. SECURE WITH SCREW.
CIRCUIT
BREAKER
BRACKET
CIRCUIT
BREAKERS
A
IR HANDLER
DECK
CIRCUIT BREAKER
MOUNTING SCREW
FIGURE 3. Electric Heat Section with Circuit Breakers
CIRCUIT BREAKER
BRACKET
CIRCUIT
BREAKERS
AIR HANDLER
DECK
PATCH PLATE
CIRCUIT
BREAKER
SEAL
AIR HANDLER
ACCESS PANEL
BREAK AT THIS POINT
DISCARD
PATCH PLATE
NOTE — IT IS HIGHLY RECOMMENDED TO USE THE
CIRCUIT BREAKER COVER (ORDERED SEPARATELY).
ORDER CATALOG # 82W01.
FIGURE 4. Circuit Breaker Seal and Patch Plate Installation

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BREAK AT THIS POINT
ROTATE 180º AND INSTALL
OVER OPENING
DISCARD
ECB27‐12.5CB
ECB27‐15CB
ECB27-4CB, ECB27‐5CB, ECB27-6CB,
ECB27‐8CB, ECB27-9CB
SIDE OF UNIT
PATCH PLATE SHOWN WITH LONGEST SECTION ON THE
RIGHT SIDE. PATCH PLATE MAY BE FACTORY INSTALLED
WITH LONG SECTION ON THE LEFT SIDE.
PATCH PLATE
(SHIPPED INSTALLED ON AIR HANDLER)
CIRCUIT BREAKER SEAL
(SHIPPED WITH ELECTRIC HEAT AND FIELD
INSTALLED)
LONG
SECTION
DOTTED LINES ARE PERFORATIONS
LONG
SECTION
LONG
SECTION
SIDE OF UNIT
ROTATE 180º AND
INSTALL OVER OPENING
DISCARD
BREAK AT THIS POINT
FIGURE 5. Circuit Breaker and Patch Plate Conguration
(Select Cases in Air Handlers with Small Cabinets)
ECB27-4CB. ECB27‐5CB,
ECB27-6CB, ECB27‐8CB, ECB27-9CB
ECB27‐12.5CB, ECB27‐15CB,
ECB27‐20CB
ECB27‐25CB ECB27‐10CB 3 Ph, ECB27-15CB 3 Ph
ECB27‐20CB 3 Ph
ECB27‐25CB 3 Ph
SIDE OF
UNIT
DISCARD
BREAK AT THIS POINT
DISCARD
BREAK AT THIS POINT
SIDE OF
UNIT
ROTATE 180º AND
INSTALL OVER OPENING
ROTATE 180º AND
INSTALL OVER OPENING
LONG
SECTION
LONG
SECTION
PATCH PLATE SHOWN WITH LONGEST SECTION ON
THE RIGHT SIDE. PATCH PLATE MAY BE FACTORY
INSTALLED WITH LONG SECTION ON THE LEFT
SIDE.
PATCH PLATE
(SHIPPED INSTALLED ON CB UNIT)
CIRCUIT BREAKER SEAL
(SHIPPED WITH ELECTRIC HEAT AND
FIELD INSTALLED)
LONG
SECTION
DOTTED LINES ARE PERFORATIONS
SIDE OF
UNIT
SIDE OF
UNIT
SIDE OF
UNIT
LONG
SECTION
LONG
SECTION
LONG
SECTION
DISCARDDISCARDDISCARD
BREAK AT THIS POINTBREAK AT THIS POINTBREAK AT THIS POINT
FIGURE 6. Circuit Breaker Heater and Patch Plate Conguration (Common Congurations)

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Circuit Breaker Cover Installation
If the air handler is installed in an unconditioned space the
provided circuit breaker cover must be installed.
1 - Use isopropyl alcohol to clean the surface that
the circuit breaker cover will be attached to.
FIGURE 7. Circuit Breaker Location
2 - Remove paper backing from foam seal around
perimeter of circuit breaker cover (gure 8).
CIRCUIT BREAKER COVER (BACKSIDE)
REMOVE PAPER BACKING FROM FOAM SEAL
FIGURE 8. Remove Paper Backing
3 - Run a bead of clear silicone around the perimeter of
the circuit breaker cover to seal any gaps between
the cabinet access door and the circuit breaker
cover.
4 - Position the breaker cover over the air handler
circuit breaker opening (gure 9).
CIRCUIT BREAKER COVER
FIGURE 9. Circuit Breaker Cover Installation
IMPORTANT
Conrm airtight seal between breaker cover and air
handler access panel. Apply a thin silicone bead to the
adhesive back seat to ensure airtight seal.
Failure to seal circuit breaker cover will allow warm
moist air to be pulled into control panel which can create
condensation to form on the circuit breaker and other
electrical components within the control panel.
Electrical Connections
IMPORTANT
USE COPPER CONDUCTORS ONLY
NOTE – Refer to the nameplate on the air handler unit
for minimum circuit ampacity and maximum over-current
protection size.
The air handler units are provided with openings to be
used with 1-1/2 inch trade size (1-31/32 inch diameter)
conduit. A conduit reducer washer has been provided if
you are installing a smaller sized conduit.
For single-point power supply, refer to the nameplate on
the single-point power supply accessory for minimum cir-
cuit ampacity and maximum over-current protection size.
Select the proper supply circuit conductors in accordance
with tables 310-16 and 310-17 in the National Electric
Code, ANSI/NFPA No. 70 or tables 1 through 4 in the Ca-
nadian Electric Code, Part I, CSA Standard C22.1. Refer
to gure 11 for typical air conditioner applications and g-
ure 12 for typical heat pump applications with an air han-
dler unit and electric heat section.
Refer to gure 13 for typical system diagram for air han-
dlers with electric heat sections.
Make wiring connections
1 - Disconnect the interface harness from the air
handler unit. Connect the plug from the heater to
the matching plug inside the air handler.
NOTE – 575V, 3-Phase, 60Hz heaters are shipped with
a line-voltage-to-460V transformer. This transformer pro-
vides 460V power to the air handler motor and transformer
only. Disconnect the 2-wire connector from the air handler
interface harness and the air handler transformer. Connect
the 575V to 460V transformer between these connections.
See gure 10 for installation location.
2 - If using a two-stage thermostat—Remove
the jumper between terminals W2 and Rof TB1
terminal block and connect the second-stage heat
bulb lead to W2.
3 - If using an outdoor thermostat — Remove the
jumper between terminals W2 and Rof TB1 terminal
block and connect leads to W2 and R.

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4 - Make wiring connections as follows:
• Heaters equipped with circuit breakers – Connect
eld power supply wiring to circuit breaker(s).
• Heaters equipped with terminal blocks – Con-
nect eld power supply wiring to terminal block(s).
• Heaters equipped with fuses (460V, 3-Phase,
60Hz and 575V, 3-Phase, 60Hz) – Connect eld
power supply wiring to fuse block. (An extension
plate is provided for J-voltage units.)
Unit Start-Up
1 - Replace the air handler access cover.
2 - Restore power to the unit.
3 - Set the thermostat heat anticipator to 0.4 amps.
4 - Align the provided wiring diagram sticker with the
air handler diagram on the blower housing. Remove
the backing and a󰀩x the sticker to the housing.
5 - Set the thermostat above room temperature.
6 - Check the system for normal operation.
7 - Set the thermostat to desired setting.
FIGURE 10. Installing Fuse Block and Transformer (575V only)
Air Handler Blower Speed Connections
When using ECB27 heat section, adjust the blower speed
according to the size of electric heat and air handler unit.
The minimum blower setting for each air handler size
with any heat sections in any application is HIGH. See
specic air handler installation instructions for blower
speed adjustment procedure.
Typical Unit Applications
Refer to gures 11 and 12 for typical eld wiring for cooling
and heat pump applications including an air handler with
electric heat.
CIRCUIT 1
CIRCUIT
BREAKERS OR
TERMINAL
BLOCK
1
4
7
3
6
9
CB1
CIRCUIT
BREAKER
NOTE - USE COPPER CONDUCTORS ONLY
REFER TO UNIT RATING PLATE FOR MINIMUM CIRCUIT AMPACITY AND MAXIMUM
OVERCURRENT PROTECTION SIZE
NOTE - ALL REMAINING WIRES FACTORY‐INSTALLED
LINE VOLTAGE FIELD‐INSTALLED
CLASS 2 VOLTAGE FIELD‐INSTALLED NEC/CEC
TO EXTERNAL LOAD 24VAC AT .50 AMP MAXIMUM
THERMOSTAT HEAT ANTICIPATION SETTING 0.4 AMP (ELECTRIC HEAT)
WHEN TWO‐STAGE THERMOSTAT IS USED, CONNECT SECOND STAGE
NALS “R” AND “W2”
FACTORY‐INSTALLED JUMPER
L3 CONNECTION USED ON (Y VOLTAGE) 3‐PHASE ELECTRIC HEATERS
ONLY
FIGURE 11. Typical Field Wiring – Cooling Application with Electric Heat

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THERMOSTAT HEAT ANTICIPATION SETTING 0.4 AMP ELECTRIC HEAT
CW1 OY1 RL T
EC
W1 GOY1 RL T
COMMON
ELECTRIC HEAT
REVERSING VALVE
COMPRESSOR
POWER
SERVICE LIGHT
THERMISTOR
Y2
2ND STAGE COMPRESSOR
Y2
CIRCUIT 1
CIRCUIT
BREAKERS OR
TERMINAL
BLOCK
1
4
7
3
6
9
CB1
CIRCUIT
BREAKER
L3 CONNECTION USED ON Y VOLTAGE 3 PHASE ELECTRIC HEATERS ONLY.
STATS.
Y2 USED ONLY WHEN TWO SPEED COMPRESSOR IS USED
(HP21).
COMMON USED ONLY ON SOME THERMOSTATS.
USING SERVICE LIGHT OPTION (S54) WITH SOME ELECTRONIC THERMOSTATS MAY REQUIRE
MOVING S54 COMMON WIRE TO Y1 IN HEAT PUMP UNIT.
EMERGENCY HEAT RELAY (USED ONLY IF OUTDOOR T'STAT IS USED) FIELD PROVIDED AND
INSTALLED NEAR INDOOR UNIT. 24VAC 5VA MAX NEC/CEC CLASS 2
MOVE JUMPER BETWEEN TERMINALS “R' AND “W2.”
FACTORY INSTALLED JUMPERS
FIGURE 12. Typical Field Wiring – Heat Pump Applications with Electric Heat

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Unit Field Wiring Diagrams
FIGURE 13. Typical Unit Diagram – Air Handlers with Constant Torque Motors
(P Voltage – 208-230V, 1-Phase, 60Hz)

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FIGURE 14. Typical Unit Diagram – Air Handlers with PSC, Non-Communicating Motors
(P Voltage – 208-230V, 1-Phase, 60Hz)

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FIGURE 15. Typical Unit Diagram – Air Handlers with Variable Speed, Communicating Motors
(P Voltage – 208-230V, 1-Phase, 60Hz)