Nordyne E2EH 010H, E2EH 012H, E2EH 015H, E2EH 017H, E2EH 020H Service Manual

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E2 Series Electric Furnaces
Service Manual
Table of Contents
Electrical Requirements......................................................................... 10
Codes, Specifications Requirements............................................................................ 10
Connection Supply Service Wires ................................................................................ 10
Air Circulator Motor ....................................................................................................... 9
Air Circulation Switch .................................................................................................... 8
Heating Elements ......................................................................................................... 7
Cooling Relay ............................................................................................................... 7
Limit Switches............................................................................................................... 8
Sequencer .................................................................................................................... 6
General..................................................................................................... 4
Furnace Specifications ................................................................................................. 4
Model Identification Code ............................................................................................. 4
Serial Number Identification Code ................................................................................ 4
Selecting Blower Speeds ...................................................................... 11
Blower Performance ..................................................................................................... 12
Changing Blower Speeds............................................................................................. 11
Service Diagrams ................................................................................... 21
4-7 Wire Relay Box for H/P E2EB 020 and 023 Units................................................... 23
2-Wire Relay Box for A/C E2EH 020 and 023 Units ..................................................... 21
4-7 Wire Relay Box for H/P E2EH 020 and 023 Units................................................... 22
Thermostat Sequence of Operation..................................................... 12
Wiring Diagrams ..................................................................................... 13
E2EB 010 ..................................................................................................................... 17
E2EB 012 ..................................................................................................................... 18
E2EB 015,017 ............................................................................................................... 19
E2EB 020, 023.............................................................................................................. 20
E2EH 010 ..................................................................................................................... 13
E2EH 012 ..................................................................................................................... 14
E2EH 015,017 .............................................................................................................. 15
E2EH 020, 023 ............................................................................................................. 16
3 E2 Service Manual
General
g
E2 series electric furnaces are approved for use in mobile/modular homes. The E2 series furnaces are approved for downflow and upflow installations as free standing units, or for alcove installations. All furnaces models are approved for “zero” inch clearance from combustible materials. For downflow alcove installations a grille with frame may be attached to the top of the furnace and all paneling and trim flushed to it.
MODEL IDENTIFICATION CODE
E 2 EB - 010 H - A
Product Type
E -Electric Furnace
This installations provides an access door for future installation of an air conditioning/heat pump coil. All E2 series furnaces are A/C, heat pump adaptable. Refer to table 2 For optional air conditioner/ heat pump equipment. The E2 series includes two models: E2EH and E2EB models. The E2EH models are equipped with a two speed blower and require the addition of a replay package for the addition of air conditioning or heat pump. The E2EB furnaces are equipped with a multi-speed (4-speed) blower, blower relay, and cabinet insulation.
Options A -A/C Ready
Electrical Code H - 240-1-60
Generation
2 - Second Series
Product Identifier EH - Heat Only EB - A/C Blower Equipped
Primary Capacity 010 - 10 kw 012 - 12 kw 015 - 15 kw 017 - 17 kw 020 - 20 kw 023 - 23 kw
SERIAL NUMBER IDENTIFICATION CODE
E
Electric
Design Series
Manufacured Housing
Electric Furnace Models E2EH E2EB
010H 012H 015H 017H 020H 023H 010H 012H 015H 017H 020H 023H
Rated Heating Output, Btuh (see note1)
Watts (T otal kw, Heat ing Elements and
Heating Elements, No. (Total kw) 2 (10. 0) 2 (11.6) 3 (15.0) 3 (16.2) 4 (20.0) 4 (21. 6) 2 (10.0) 2 (11. 6) 3 (15.0) 3 (16.2) 4 (20.0) 4 (21.6)
Blower: Wheel Size 10.5" Dia., 8" Wide 10.5" Dia., 8" Wide
Motor S peeds, H.P. Rat ing, A mps 2 Speed, 1/5 Hp, 2. 0 A mps 4 Speed, 1/3 Hp, 2. 9 A m ps
Test ESP, in. w.c. Max 0.3
Optional Coolin installed blow er
Opt ional Heat Pump Available with fac tory installed blow er
Available with factory
Air Filter (St andard) 16" x 20" x 1" ( nominal)
Furnace Dimensions Width - 20" (508 mm ) Height - 29" (737 mm ) ( s ee not e 2) Depth - 24- 1/ 2" ( 623 mm )
Blower) 10.4 12.0 15.4 16.6 20.4 22.0 10.4 12.0 15.4 16.6 20.4 22.0
Supply Voltage 240/208 Volts/60Hz/1-Phase
35,000 41,000 53,000 57,000 70,000 75,000 35,000 41,000 53,000 57,000 70,000 75,000
2.0 - 3.0 ton (see note 3) n/a (see not e 3) 2.0 - 4. 0 t on (s ee not e 4)
E
2
2.0 - 3.0 ton (see note 3) 2.0 - 4. 0 t on (s ee not e 4)
9705
01234
Production Code
Month
Year
1. Heating output rated at listed voltage. For outputs at voltages other than 240V, multiply Btuh rating by the following factors: x 0.92 (230V), x 0.84 (220V), x 0.75 (208V)
2. Height is 56" with return air grille installed, 58" with coil cabinet and 72" with coil cabinet and upflow stand.
3. The factory installed blower for the EH models can be replaced with a multi-speed blower allowing the units to accept up to 4 or 5 tons of air conditioning or heat pump.
4. The factory installed blower for the EB models can be replaced with a multi-speed blower allowing the units to accept up to 5 tons of air conditioning or heat pump.
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Table 1. Unit Specifications
Item
8
Number
(See Fig. 1)
1 4-Sp eed B lower
4 T on - S ee Notes: 1 & 5 5 T on - S ee Note: 1
2 A.C./H.P. Relay Control Box
(not r eq’d on E2EB m odels ) See Note: 1
3 Cabinet I ns ulation Kit
See Not es : 1 & 5
4 "A "-Coil Convers ion K it
See Note: 2
5 Coil Cabinet
See Note: 3
6 Upfl ow S tand
See Note: 4
7 A/C and H/ P Indoor Coils
8 Retu r n A i r Grille and Frame
Assembly
No tes :
1) For A/C and H/P use.
2) Includes co il filters.
3) For upflow or downflow installations.
4) For upflow A/C or H/P installations (includes on e f i lter; use f ilter from furnace t o complet e filtering syst em in thi s acces sory).
5) Standard in EB models.
Descrip ti on
4
Cabinet
Insulation
23 3/4”
(603 mm)
7
27” (686 mm)
1
2
29” (737 mm)
3
20”
(508 mm)
20” (508 mm)
29” (737 mm)
Table 2. Optional Air Conditioning and
Heat Pump Equipment
Sequence of operation
With the circuit breakers in the on position and the blower switch in the auto position. One half of the control heating element and motor electrical circuit is activated. When the contacts close in the wall thermostat 24 volts is supplied by the 240/24 volt transformer to the sequencer heater. This heats a bi ­metal in the sequencer which closes a set of contacts and completes the circuit to the no.1 element and the blower motor. As the heater continues to build up heat, the bi-metal closes the remaining circuits to other elements, until all elements are on. The “off” cycle is reverse of the “on” cycle the blower and no.1 element are first on and the last to be de-energized.
23 3/4”
(603 mm)
5
Coil Cabinet
20” (508 mm)
14” (357 mm)
23 3/4” (603 mm)
Filters (one obtained from furnace)
6
Upflow Stand
NOTE: See Table 2 for descriptions and notes
Figure 1. Optional Accessories
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Sequencer (Figure 2)
In general all sequencers operate the same way. In some applications one sequencer may be sufficient (10 and 12 kw models) in other applications. One two or more sequencers may be required.
Important: Sequencers should never be mixed. If different brands of sequencer are used and their timing may be different.
Testing Sequencer
1. Shut off the power supply to the furnace, there could be two circuits. Be sure both "A" and "B" circuits are de-energized.
a. Remove all wires from the sequencer (making
note of wire color and terminal location). The bi-metal heater portion of the sequencer will be unmarked and at the bottom, closest to the mounting plate. The switching portion will be marked M1 through M8 depending on the number of switches. Refer to unit wiring diagram.
b. With an ohmmeter, test for continuity across
the bi-metal heater terminals. There should be 70 to 90 ohms of resistance. If the meter reads no continuity, the bi-metal heater is open and must be replaced. The OHMS value should be 70 to 90 across the bi-metal.
Figure 2. Sequencer
c. With an ohmeter check all switches in the
sequencer. They are labled M1-M2, M3­M4...refer to Figure 2. All of the switches should be open and have no continuity.
2. With all power on to furnace, and thermostat contacts closed: using a voltmeter (set scale for 220 vac.) On contact terminals of sequencer, check each set of terminals of sequencer, check each set individually. If you read voltage, contacts are open. If you do not read voltage, contacts are closed. Allow a maximum time (110 seconds) for heater to close contacts. If any of the contacts remain open after three minutes the sequencer is defective and should be replaced.
Indoor Coil (optional)
Coil Air Filters (used with indoor coil)
Furnace Air Filter (NOT used with indoor coil and coil air filters)
Data Label
Blower
A/C or H/P Relay Box (optional)
Blower Selector Switch (next to blower)
Control Panel Cover (right)
Control Panel Cover (left)
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Circuit Breakers
Refer to unit wiring diagram section for wiring of sequencer for each model furnace.
Control Transformer (Figure 3)
All E2 furnaces are equipped with a 30 VA, 240/208 vac primary, 24 vac secondary transformer.
The function of the transformer is to supply the 24 volts for the low voltage circuit which activates the controls. Note: never replace a transformer with one of less VA rating: however a higher rated transformer can replace a lower rated unit. Example: unit has 30 VA replacement can be 40 VA.
Checking Transformer
1. Using a voltmeter, test power supply on the primary leads of the transformer- must be 240 v +/- 10%. If less than 226 vac switch black and blue primary leads.
2. Remove wires from the secondary side of the transformer. Or find the area where the wires terminate and remove from component.
3. Use the voltmeter check the output of the transformer, it should read 22 to 28 volts. If not,
Figure 5. Heating Elements in Furnace
then the transformer is nonfunctional and should be replaced. Observe the transformer there should be no distortion in shape, oil residue or odor. If any of these symptoms exist replace the transformer.
Heating Elements (Figures 4 & 5)
The heating elements used are of modular design consisting of helical-coiled nichrome resistance wire. An insulated wire formed assembly supports the heating elements. All elements are rated at 240 volts. Each element is individually controlled by a switch of the sequencing system and is protected by a limit switch.
Figure 3. Transformer
The function of the heating element, of course, is to heat the air passed across them by the blower system.
Testing Heating Elements (Ohmmeter)
1. Shut off all electric supply to furnace
2. Remove all wires from terminals of heating coils
3. Using the ohmmeter test from terminal to terminal of the coil-must show continuity-if not replace element assembly.
4. Using the ohmmeter test from heating element terminal to ground wire in the control panel, there should be no continuity. If there is the coil is grounded and must be replaced.
Caution: Heating elements must always be replaced by an identical kW replacement. Substitution by higher kW’s or elements of a different design may result in unsafe operation of the furnace. Lower kW rated elements will reduce output and may result in unsatisfactory operation of the appliance. Refer to element rating labels and furnace wiring diagrams.
Figure 4. Heating Element
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Figure 6. Cooling Relay
Cooling Relay (Figure 6)
The E2EB has a factory installed cooling relay. The cooling relay operates the air circulator at the high speed when the relay is energized. The relay is energized by the low voltage circuit by the g terminal of the thermostat. At the same time it breaks the circuit to the heating speed of the air circulator. the cooling relay has one set of normally closed and one set of normally open contacts.
Testing Cooling Relay
1. Turn off all power supply to furnace. a. Remove all wires from cooling relay. b. Using ohmmeter, test from terminal no. 1 to
terminal no.3 the coil should have resistance of around 76 ohms. If there is no continuity, the relay has a open coil and must be replaced.
c. Using ohmmeter, test from terminal no.5 to
terminal no. 6 there should be continuity, if no continuity is shown relay is defective and must be replaced.
d. Replace wires on terminal no.1 and 3 restore
power supply.
e. Energize relay by positioning the fan switch on
the thermostat to the fan position. The relay should click.
f. Using ohmmeter, test terminals 2 and 4 there
should be continuity. If no continuity relay is defective.
g. Turn off all power to furnace, reconnect all
wires to relay and restore power.
Figure 7. Limits in furnace
The limit device is a safety which can be compared to a fuse or a breaker in a electrical circuit. The function of the limit switch is to open the electrical circuit to the heating elements if over heating should occur. This could be caused by air circulator failure, dirty filters, lack of return air, restricted ducts, etc. All limit switches used are of the automatic reset type. On cool down they will automatically reset.
Testing the Limit Switches
1. Shut off all electric supply to furnace.
2. Allow enough time for limit to cool down ( 5 to 10 minutes)
3. Remove wires from terminals of limit switches. Note: all limit switches will be located on the heating element rack face plate with red wires attached to them.
4. Using the ohmmeter, test from terminal to terminal continuity must be read. If no continuity is read after cool down time, switch is defective and should be replaced.
Caution: Limit switches must always be replaced by their identical replacement part, i.e. Same setting, style limits on the E2 series are either single or double pole type thermo disc. Under no circumstance should a limit of a higher setting or of a different type be installed. Replacement with a lower setting limit may result cycling of the control and insufficient heat output.
Air Circulation Switch
The air circulation switch is a manual rocker type switch, single pole double throw, the switch when in the “auto” position, allows the blower to be activated by the
Limit switches
A limit switch is a heat sensing device utilizing a bi­metal disc to open a set of normally, closed contacts.
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Figure 8. Air Circulation Switch
sequencer. The blower will run during the heating cycle of the furnace. When the switch is in the “fan” position the blower will run continuously. See Figure 8 for air circulation switch.
1
Black
* Yellow on E2EH 015, 017, 020, 023
Figure 9. Fan Switch Shematic
2
Red*
3
Yellow
Checking the Air Circulator Selector Switch
To check the air circulator switch shut of all power to the furnace. Remove wires from air circulator selector switch terminals. Check continuity of terminals with the switch in “on” and “auto” position. See Figure 9 for fan switch schematic.
Capacitor(See Figure 10):
1. Shut off the electrical supply to the unit.
2. Disconnect he electrical leads to the capacitor.
3. Discharge the capacitor using a 1500 ohm resister.
4. Check the capacitor using a capacitor tester. Blower Motor (See Figure 11):
1. Shut power off to the furnace.
2. Disconnect the electrical motor leads.
3. Using an ohmmeter, check for continuity from each
terminal to the shell of the motor, if there is continuity, the motor is grounded and should be replaced.
4. Using the ohmmeter, check the resistance across
the motor leads. See diagrams below. Note: the higher the speed the lower the resistance of the motor winding.
Air Circulator Motor
The circulator motor and blower wheel combination move air across the heating elements to supply the duct system with warm air.
To check the motor, be certain the capacitor is functional.
Figure 10. Capacitor
Figure 11. Blower
Figure 12. Motor Schematic
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