Johnson Controls ZL Series Installation Manual page 75

Flash codes
Table 42: Flash codes for the gas heat ignition control board
Flash code Description
Normal Operation - no status
Heartbeat
or error information currently
needs to be displayed
Steady off a. No Power to the Control - Less
than 18 VAC is present at the
ignition control's R (P2-2 pin)
and C (P2-1 pin) connections
b. The ignition control has
catastrophic damage that will
not allow the LED display (it is
likely that there will be visible
physical evidence of the damage)
Steady on The ignition control's
microprocessor has not
passed its self-check
2 flashes The Induced Draft Pressure Switch
Did Not Close - 24 VAC was not
received to the ignition control's
pressure switch input (P1-8
pin) within 10 seconds of the
ignition control energizing
the induced draft motor or
24 VAC was later lost to the
control's pressure switch
input while the ignition control
energized the induced draft motor
3 flashes The Induced Draft Pressure Switch
is Stuck Closed - 24 VAC is received
to the control's pressure switch
input (P1-8 pin) at the same time
as 24 VAC to initiate heating
operation is received at the
control's W1 input (P2-3 pin)
4 flashes Flame Could Not Be Established
- A flame signal of 0.2μa
or greater could not be
established in three consecutive
attempts for ignition at the
initiation of the heating cycle
5 flashes Flame Loss - After being
established during ignition trials,
flame signal dropped below 0.2μa
five times during one heating cycle
Technician corrective action
None.
Verify line voltage is present at the primary of the 75VA transformer,
verify 24 VAC is present at the secondary of the 75VA transformer.
Verify 24 VAC is present from the UCB's C to SD terminals indicating
the 3.2A control circuit breaker and phase monitor contacts are closed.
Verify 24 VAC is present at the ignition control's R (P2-2 pin) and C (P2-1
pin) connections indicating the unit to ignition control wiring is intact.
Cycle power to the control to eliminate the possibility that transient
voltage conditions such as surges, brownouts, etc. have not created
a false indication. If the steady on LED indication repeats, the control
will need to be replaced and potential causes for failure, such as
excessive voltage, RF interference, etc. should be investigated.
Verify that the induced draft motor is operable, the ignition
control's L1 to IND contacts are not open, the induced draft blower
wheel is intact and there are no blockages in the combustion
air / induced draft path. Verify that the induced draft pressure
switch sensing tubing is intact. With an incline manometer,
digital manometer or Magnehelic gauge teed into the pressure
®
switch sensing line verify that the negative pressure exceeds
the setting listed on the induced draft pressure switch label
and the switch's contacts correctly close at the setting listed
Verify that the induced draft pressure switch contacts are not
stuck or welded closed. Verify that the ignition control's L1 to IND
contacts are not stuck or welded closed causing the induced draft
motor to run continuously. Verify that the wiring from the ignition
control's P1-3 pin through the induced draft pressure switch to the
ignition control's pressure switch input (P1-8 pin) is not shorted.
Verify that the unit has proper electrical grounding. Verify the 24
VAC common and ignition control cabinet ground references are
intact. Monitor the flame signal. Verify that combustion air openings
are without blockages and that the unit has proper clearance to the
structure and adjacent units. Verify that the burners are clean and
without blockages that could interfere with gas flow. Verify that the
ignitor sparks with an ≈1/8" gap to the crossover area of the left
burner. Verify that the flame sensor is intact and positioned with an
≈1/8 in. gap to the right burner. Verify that the gas lines have been
purged of air and provide proper gas inlet pressure. Verify that the gas
valve is opening and adjusted to provide proper manifold pressure.
Verify that the wiring to the gas valve is intact. Verify that there is no
wind, rain or snow entering the heat compartment to interfere with
ignition or the burners. Verify that there are no conditioned air leaks
or heat exchanger breaches to interfere with ignition or the burners.
Verify that the unit has proper electrical grounding. Verify the 24
VAC common and ignition control cabinet ground references are
intact. Monitor the flame signal. Verify that combustion air openings
are without blockages and that the unit has proper clearance
to the structure and adjacent units. Verify that the burners are
clean and without blockages that could interfere with gas flow.
Verify that the flame sensor is intact and positioned with an ≈1/8
in. gap to the right burner. Verify that the gas lines have been
purged of air and provide proper gas inlet pressure. Verify that
the gas valve provides proper manifold pressure. Verify that the
wiring to the gas valve is intact. Verify that there is no wind, rain
or snow entering the heat compartment to interfere with ignition
or the burners. Verify that there are no conditioned air leaks or
heat exchanger breaches to interfere with ignition or the burners.
Installation Manual ZL Series 7.5- 12.5 Ton 60 Hertz R-410A
Johnson Controls Ducted Systems
Ignition control Method for reset
response to flash code
All functions available to
respond to heating demand.
The output relay contacts a. Restoration of
open so inducer and gas valve 24 VAC power to
operation is not permitted. the ignition control.
The output relay contacts
open so inducer and gas valve power to the ignition
operation is not permitted. control or expiration
of the 60 minute
watchdog timer.
Gas valve operation is not
permitted/ends when the induced pressure switch
draft pressure switch input is not (24 VAC input to
present. The ignition control's P1-8 pin), cycling
L1 to IND output relay contact
will cycle closed for 5 minutes/ input or cycling 24
open for 30 seconds until 24 VAC VAC power to the
is received to the pressure switch ignition control.
input or the heating demand ends.
The output relay contacts
open so inducer and gas valve pressure switch
operation is not permitted. (loss of 24 VAC input
to P1-8 pin) then
cycling first stage
heat input or cycling
24 VAC power to
the ignition control.
Immediately after the third Cycling first stage
ignition trial: the gas valve output heat input, cycling
relay contact opens so gas valve 24 VAC power to
operation is not permitted, the ignition control
following a 5 second inducer or expiration of
post purge the induced draft
output relay contact opens so watchdog timer.
inducer operation is not permitted.
Immediately after the fifth flame Cycling first stage
loss: the gas valve output relay heat input, cycling
contact opens so gas valve 24 VAC power to
operation is not permitted, the ignition control
following a 5 second inducer or expiration of
post purge the induced draft
output relay contact opens so watchdog timer.
inducer operation is not permitted.
None.
b. None.
Cycling 24 VAC
Closure of the
first stage heat
Opening of the
the 60 minute
the 60 minute
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