Nortron ECM Series Electric Furnace

Important Safety Information

WARNING

• Do not tamper with the unit or its controls. Contact a specialized contractor for any failures. DO NOT ATTEMPT to repair.
• When using a humidifier, ensure it does not damage the heating element bank.
• Poor maintenance of air filters or unbalanced static pressure may result in performance decrease.
• Always use genuine Nortron parts for maintenance or service calls. Use of unbranded parts or operating the unit without an air distribution duct will void the warranty.
• It is strictly forbidden to use jumpers to simulate heat demand.
• Risk of electrical shock: Disconnect power before installation, servicing, maintenance, or field wiring. Replace all panels before operating. Failure to do so can result in electrical shock causing severe injuries or death.
• When performing installation, servicing, or cleaning, wear safety glasses and gloves.
• Use high-quality name brand thermostats for proper performance.
• If local regulations have more restrictive requirements, they prevail over this document.
• Do not store or use gasoline or other flammable liquids and vapors near the unit.
• These instructions are for qualified personnel. Unqualified installation may lead to equipment damage or hazardous conditions.
• This furnace is not watertight and not designed for outdoor installation. Protect electrical components from water to prevent hazardous electrical conditions and premature failure.
• Do not block combustion air openings; this can cause improper overheat, fire hazard, or bodily harm.
• Ensure an uninterrupted electrical ground connection.
• Do not use this furnace as a construction heater, as it exposes the unit to abnormal conditions and contaminated air, potentially leading to premature failure or vent failure.
• Owner/user responsibility: Keep surroundings free of combustibles, maintain low dust and humidity, and never operate without an air filter.
• Turn all utilities OFF before performing service functions, unless power is required.
• Address all questions regarding operation, maintenance, or warranty to the company where the product was purchased.

CAUTION

• Never burn garbage or paper in the heating system. Keep rags or paper away from the unit.
• Return air grilles and warm air registers must not be obstructed.

Applicable Codes: Follow all local and national code requirements. Applicable codes may include ANSI/NFPA 70 NATIONAL ELECTRICAL CODE and CSA C22.1 CANADIAN ELECTRICAL CODE. Consult the latest issues of these codes.

1 Dimensions

Diagram Description: A line drawing illustrating the front, right side, rear, left, and top views of the Nortron ECM Series electric furnace. It shows overall dimensions and key features like filter frame placement and wiring knockouts (KO's).

• Front View: Overall height: 39.00 inches (991 mm). Filter frame can be on the side, rear, or bottom.
• Side Views (Right/Left): Return air opening: 18" x 18" (457 mm x 457 mm). Wiring knockout (KO) sizes: A = 1 3/8" (35mm), B = 1 1/4" (32mm) and 1 3/4" (44mm), C = 7/8" (22mm) and 2" (50mm).
• Rear View: Return air opening: 18" x 18" (457 mm x 457 mm).
• Top View: Discharge opening: 17" x 17" (432 mm x 432mm).

2 General Requirements and Specifications

CAUTION

Install the unit in a dry, non-corrosive, well-ventilated environment with minimal dust. Ambient temperature should be between 10°C and 27°C (50°F and 80°F). If ambient temperature is 10°C or below, the plenum requires a minimum of 10 ft. linear insulation.

1. LOCATION: The furnace should be centrally located to the heating area.
2. POSITIONS: Installation can be vertical, horizontal, or downflow. For horizontal installation, the door must be on the side, not the top, to ensure proper motor bearing orientation. For vertical downflow, use "L"- or "T"-shaped plenum with no openings or registers directly below the furnace.
3. INSTALLATION CLEARANCES: Units are approved for "zero inch" clearance as shipped. Additional clearance requirements will be indicated on the furnace data label.
4. TEMPERATURE RISE: Furnaces are shipped to operate at 0.20" W.C. (50 Pa) external static pressure and are certified for operation up to 0.50" W.C. (125 Pa). Refer to the specification chart for temperature rise.
5. SERVICE CLEARANCE: Units are serviced from the front. Maintain at least 24" (610 mm) clearance in front of the door.

240 VOLTS - SINGLE PHASE Specifications

*FACTORY SETTINGS. **Models 21ECM15-A through 21ECM23-A must NOT be set up to run continuously at LOW speed, as this will cause overheating. These models are certified to run only at HIGH and MED speeds.

Specifications are subject to change without notice.

Flow Rate vs. Static Pressure

3 Operating Options

The furnace is shipped in "Standard Heating Mode" with all switches in the down position. When the thermostat calls for heat, automatic controls activate the furnace. The blower operates at a speed selected by the SPEED SELECTOR switch. As the furnace heats up, it may automatically switch to higher speeds based on activated elements and the SEASON SELECT switch (COLD or MILD).

SPEED SELECTOR: Controls fan speed for ventilation.

• HIGH: Blower motor operates at a higher speed.
• LOW: Blower motor operates at a low speed.

SEASON SELECT:

• MILD: Approximately half of the heating elements are off-line. Used for milder weather or when full capacity is not needed.
• COLD: All heating elements are online and controlled by the thermostat. Used for colder weather.

NOTE: If using an outdoor or two-stage thermostat, the SEASON SELECT switch MUST be set to MILD at all times. This switch has no effect on the 10 kW model.

4 Breakers

ECM Series furnaces have breakers on the front panel to protect heating elements from overcurrent. If an overcurrent occurs, the breakers trip, cutting power only to the heating elements.

Breaker Count by Model:

• 21ECM10: No breakers
• 21ECM15, 21ECM18, 21ECM20: 2 breakers
• 21ECM23: 3 breakers

Refer to Section 8 for Wiring Diagrams.

WARNING: Breakers do not cut power to the entire furnace, only to the heating elements. Do not use breakers to turn off the furnace. Power must be cut from the main electrical panel.

5 Installation Notes

5.1 Cold Air Return

The cold air return duct can be attached to the side, rear, or bottom of the furnace. For side returns, four 1 1/2" (38 mm) knockouts are provided for cutting an 18" x 18" (457 mm x 457 mm) opening. Mount the filter frame over the opening with its open side facing front, then attach the 19" x 19" (483 mm x 483 mm) air duct. For bottom mounting, remove the bottom plate and attach the filter frame to the bottom flanges.

5.2 Electrical Wiring - Power Supply

Furnaces are factory wired. A two-wire plus ground supply wire is required for single-phase units, and a three-wire plus ground for three-phase units. The ground conductor must be firmly attached to the ground lug. Supply wires connect to the terminal block. All cables must be secured at entry points using grommets for sealing and strain relief. Electric cabinet openings must be sealed.

For all installations, use appropriate gauge, good quality copper wire. The electrician is responsible for ensuring wiring and connections comply with the latest Canadian Electrical Code and local codes.

5.3 Connecting and Adjusting the Low Voltage Thermostat

Use only class 1 wires inside furnace compartments. Attach thermostat wires to the low voltage terminal block inside the furnace, following the thermostat's diagrams. Generally, R & W terminals control single-stage heating; R & Y control cooling. Single-stage cooling uses "Y/Y2"; two-stage cooling uses "Y1" (first stage) and "Y/Y2" (second stage). Ensure the thermostat is level and properly located.

CAUTION: Set the heat anticipator in the thermostat properly before turning the furnace on. Measure current draw with an AC meter (2A range for furnaces up to 20 kW, 4A for larger units). Set the anticipator to its highest setting, disconnect the "W1" wire, connect the meter between the "W1" terminal and the wire, turn on the thermostat to start the furnace, let it run for 3-4 minutes, read the current draw, and reset the anticipator to match.

6 Use in Mobile Homes

Models from 10 kW to 20 kW are certified for "L"-shape and "T"-shape shallow duct installation with the FSB-1 sub-base in downflow applications, where supply air ducts pass through the floor. Recommended floor opening size: 14.25" x 14.25" (362 mm x 362 mm). The duct system must be designed so the external static pressure does not exceed 0.50" W.C. (125 Pa).

Shallow Duct Area Requirements

7 Using Optional Equipment

7.1 Two-Stage or Outdoor Thermostat

The SEASON SELECT switch must be in the MILD position for these controls. They can be used on all furnaces except the 10 kW model. Follow the thermostat's instructions and the furnace wiring diagram. The chart below shows furnace stage heating:

7.2 Air Conditioning

The furnace is equipped with controls for air conditioning addition (thermostat not included). The evaporator coil should be installed by a local contractor in the plenum, centered over the furnace "chimney" and 4" to 6" (102 mm to 152 mm) above the furnace top. Ensure no air bypasses the cooling coil during operation. A bypass damper may be needed for heating if the discharge opening is significantly larger than the coil. The damper closes in summer to direct air through the coil and opens in winter to allow bypass.

Typical Air-Conditioning Field Wiring Connections:

Wiring Color Code:

8 Wiring Diagrams

WARNING: Risk of electric shock. Disconnect power before installation, servicing, maintenance, or field wiring. Replace all panels before operating. Failure to do so can result in electric shock causing severe injuries or death.

Diagram Description: Detailed electrical schematics showing the internal wiring of the Nortron ECM Series furnaces. Includes a comprehensive legend that translates symbols, component names, and wire colors. Some diagrams and legends include French translations (e.g., "CODE DE COULEUR", "LÉGENDE"). Specific wiring configurations are noted for 15 kW and up, 18 kW and up, and 23 kW models.

9 Service Parts

To maintain optimal performance, use only genuine Nortron replacement parts, which are designed and manufactured to comply with safety standards. Using third-party parts may cause damage and reduce performance.

Diagram Description: An exploded view diagram of the furnace components, with each part numbered. A table lists the part number and description for each numbered component.

Service Parts List

10 Maintenance

MOTOR: The motor is lubricated for life and requires no oiling.

FILTERS: Size is 20" x 20" x 1" (508 mm x 508 mm x 25 mm). Inspect and replace when dirty. Replacement is typically needed twice per heating season, or more if continuous blower operation is used.

NOTE: The heating elements have an automatic reset thermal cut-out set to open at 100°F (38°C). If it opens, the elements will be de-energized until the cut-out resets.

WARNING: Cut 240V power supply before removing the front panel. The unit's breakers only cut power to the heating elements, not the entire furnace. Always use the main electrical panel to shut off power to the unit.

11 Troubleshooting

The first step in troubleshooting is to determine if the fault lies within the furnace itself or with the thermostat and its wiring.

If the furnace will not start: Turn the thermostat to its highest setting. If 24V is present between terminals C and W, the thermostat has closed, indicating the fault is in the furnace. Otherwise, the problem is with the thermostat or its wiring.

If the furnace will not turn off: Turn the thermostat to its lowest setting. If there is no more 24V between terminals C and W and the furnace continues to run, the thermostat has opened correctly, and the problem is in the furnace. Otherwise, the fault is in the thermostat or its wiring. After isolating the fault area using the thermostat, check the following components:

12 Warranty

SIXTY-MONTH LIMITED WARRANTY FOR NORTRON PRODUCTS

Nortron warrants its products to be free from defects in materials or workmanship for sixty (60) months from the date of original purchase. No other warranties, express or implied, including warranties of merchantability or fitness for a particular purpose, are made.

During the warranty period, Nortron will, at its option, repair or replace any defective product or part at no charge. The customer must ship the product or part prepaid to the factory or an authorized service center.

Warranty Exclusions: This warranty does not cover filters, separately sold furnace kits, ducts, or accessories. It also excludes normal maintenance, misuse, negligence, accidents, improper maintenance or repair (other than by Nortron), faulty installation, or installation contrary to recommended instructions. Nortron is not responsible for transportation costs of repaired or replaced products or reinstallation costs.

Implied warranty duration is limited to sixty months. Some jurisdictions may not allow limitations on implied warranty duration.

Nortron's obligation is limited to repair or replacement. Nortron is not liable for incidental, consequential, or special damages arising from product use or performance. Some jurisdictions may not allow these limitations.

This warranty grants specific legal rights, and you may have other rights that vary by province. This warranty supersedes all prior warranties and applies only within Canada.

To qualify for warranty service: Notify Nortron with the model number, part identification, and a description of the defect. Provide proof of original purchase date.

Nortron Contact: 3400 Boul. Industriel, Sherbrooke, QC, J1L 1V8 | www.dettson.com | 800-567-2733