Bradford White EF120T4003N3, Руководство по обслуживанию

Страница: 30 / 48

30
Service Procedure V:
Blower Testing and Replacement
Are collector high limit
switch and pressure
switches in normally
closed position?
Refer to ignition
control board
illustration below. Is
there 24-28VAC
between blue and
yellow wires at
location J8?
Is there 120VAC across
the white and black
wires at the incoming
power harness
connection? (see image
to right).
Refer to ignition control
board illustration below. Is
there 24-28VAC between
blue and yellow wires at
location J8?
Determine power source
problem and correct.
Check amp draw
through black wire
lead of blower motor.
Is there approximately
1.5 to 5.5 amps?
Replace blower (see
Blower Replacement
Procedure, pg 31).
Are collector high
limit switch and
pressure switches in
normally closed.
Correct safety
circuit problem per
safety circuit trace
(see Blocked Vent
Pressure Switch
Testing, pg 33).
Replace ignition
control board.
Is there 120VAC
across white and
black wires at the
blower? (see
image above).
Repair/replace
wire harness.
Replace blower (see
Blower Replacement
Procedure, pg 31).
Call
Technical
Support.
Is blower wheel
secured to blower
motor shaft?
YY
Does blower energize?
Ensure digital display
shows “Heating.” Raise
temperature setpoint if
necessary.
Replace ignition
control board.
Y
Y
Y Y
YY
YY
N
N
N
N
N
N
Y Y
Y
N
N
N
Y
120 VAC
power
connection
Black wire
leading to
blower looped
through amp
probe
120 VAC check at
blower
Check vent.
Correct safety
circuit.
120 Control Board Schematic
J8 Molex Connector
30