background image

8 E2 Service Manual

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.

Limit switches
A limit switch is a heat sensing device utilizing a bi-
metal disc to open a set of normally, closed contacts.

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

Figure 8. Air Circulation Switch

Figure  7. Limits in furnace

Summary of Contents for E2EB 010H

Page 1: ...E2 Series Electric Furnaces Service Manual ...

Page 2: ......

Page 3: ...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 ...

Page 4: ...tratedatlistedvoltage Foroutputsatvoltagesotherthan240V multiplyBtuhratingbythefollowingfactors x0 92 230V x0 84 220V x0 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...

Page 5: ...1 element and the blowermotor Astheheatercontinuestobuildupheat 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 Table 2 Optional Air Conditioning and Heat Pump Equipment Item Number See Fig 1 Description 1 4 Speed Blower 4 Ton See Notes 1 5 5 Ton ...

Page 6: ...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 M3 M4 refertoFigure2 Alloftheswitchesshould be open and have no continuity 2 With all power on to furnace and thermostat contacts closed u...

Page 7: ...e replaced Caution Heating elements must always be replaced byanidenticalkWreplacement Substitutionbyhigher 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 Refer to unit wiring diagram section for wiri...

Page 8: ...metal disc to open a set of normally closed contacts 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 lackofreturnair restrictedducts etc Alllimitswitches used are of the...

Page 9: ...eiscontinuity 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 Figure 11 Blower Figure 9 Fan Switch Shematic Figure 12 Motor Schematic Checking the Air Circulator Selector Switch Tochecktheaircirculatorswitchshutofallpowertothe furnace Remove wires...

Page 10: ...onnecting Supply Service Wires 1 Remove right hand control panel when viewing in downflow position 2 Locate power supply hole plugs in side of unit and in bottom of unit Remove appropriate plug s or knockoutopeningapplicabletorecommendedwire size s 3 Install listed cable connector s in opening s If metal sheathedconduitisusedforincomingpower line s provideanapprovedmetalclamponconduit and secure i...

Page 11: ...yorpropertydamage make certain that the motor leads cannot come into contact with non insulated metal components of the unit See Table 4 for the lowest speed approved for the heating output of the unit Since the blower leads connect to the controlbox blowerspeedselectionisaccomplishedthrough use of the proper color coded blower lead located inside the controlbox Thespeed s setbythefactorymaybediff...

Page 12: ...nd set ventilate switch to AUTO Cooling system and air circulator blower should turn on 3 Check air temperature at supply duct registers 4 Move temperature setting lever until left hand cooling contacts open Cooling system and air circulator blower should turn off 5 Replace thermostat cover For Continuous Air Circulation and Ventilation NOTE ForCM65 seefurnaceowner smanualonindepen dent blower ope...

Page 13: ...13 E2 Service Manual Figure 15 E2EH 010 Wiring Diagram ...

Page 14: ...14 E2 Service Manual Figure 16 E2EH 012 Wiring Diagram ...

Page 15: ...15 E2 Service Manual Figure 17 E2EH 015 017 Wiring Diagram ...

Page 16: ...16 E2 Service Manual Figure 18 E2EH 020 023 Wiring Diagram ...

Page 17: ...17 E2 Service Manual Figure 19 E2EB 010 Wiring Diagrams ...

Page 18: ...18 E2 Service Manual Figure 20 E2EB 012 Wiring Diagram ...

Page 19: ...19 E2 Service Manual Figure 21 E2EB 015 017 Wiring Diagram ...

Page 20: ...20 E2 Service Manual Figure 22 E2EB 020 023 Wiring Diagram ...

Page 21: ...21 E2 Service Manual Figure 23 Two Wire Relay Box for A C E2EH 020 and 023 Units ...

Page 22: ...22 E2 Service Manual Figure 24 4 7 Wire Relay Box for H P E2EH 020 and 023 Units ...

Page 23: ...23 E2 Service Manual Figure 25 4 7 Wire Relay Box for H P E2EB 020 and 023 Units Part 1 ...

Page 24: ...24 E2 Service Manual Figure 26 4 7 Wire Relay Box for H P E2EB 020 and 023 Units Part 2 ...

Page 25: ...____________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ ___________________________________________...

Page 26: ...______________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _________________________________...

Page 27: ......

Page 28: ...St Louis MO 359A 1097 Specifications and illustrations subject to change without notice and without incurring obligations Printed in U S A 10 97 R R ...

Reviews: