Johnson Controls ZL Series Installation Manual page 69

Lockout
While in lockout, the ICB keeps the main gas valve
and induced draft motor de-energized.
Lockouts due to failed ignition or flame losses may
be reset by removing the call for heat (W1) for
more than 1 second, but less than 20 seconds, or
by removing power from the control for over 0.25
seconds. The control will automatically reset lockout
after 60 minutes.
Lockouts due to detected internal control faults will
reset after 60 minutes or power interruption.
High temperature limit switch
If the high temperature limit switch is open the
control will run the inducer, de-energize the gas
valve, and flash 6 on the LED. When the high
temperature switch closes, the control will restart
the ignition sequence beginning with pre-purge.
If the high temperature limit is open for more than
6 minutes continuously during a call for heat, it is
assumed that the main blower has failed and the
control shall enter a hard lockout and flash a 9 on
the LED. During the hard lockout, the control will
continue to run the inducer as long as the limit
switch is open. If the limit switch closes again in this
hard lockout condition, the inducer will run a post
purge and then shutoff. The control shall remain
locked out until power is removed and shall not
reset automatically.
Roll-out switch
If the roll-out switch opens for more than 0.25
seconds, the ICB will run the inducer for a post-
purge period, immediately de-energize the gas
valve, and flash 7 on the LED.
If the roll-out switch closes, the control shall remain
locked out until power removed or W is removed.
Rollout switch lockout shall not reset automatically.
Power interruptions
Power interruptions less than 0.80 seconds shall
not cause the ICB to interrupt the heat sequence.
Power interruptions over 0.250 seconds will cause
the control reset lockout and ignition trial counters.
Power interruptions of any duration shall not
cause lockout or any operation requiring manual
intervention.
Flame present with gas off
If flame is sensed for longer than 2 seconds during
a period when the gas valve should be closed, the
ICB will enter lockout. The control will turn on the
inducer blower while the flame is present.
Welded gas valve relay response
If either or both Main and 2nd Stage Gas valve
outputs are sensed to be off for more than 1 second
when commanded to be ON the ICB shuts off all
outputs and enters lockout.
If the Main valve output is sensed to be energized
for more than 1 second when commanded to be off,
the control de-energizes the induced draft motor
(if flame is not present) to attempt to open the
pressure switch to de-energize the gas valve. If the
Main gas valve is still sensed as energized after the
inducer has been off for 15 seconds, the control
re-energizes the inducer to attempt to vent the
unburned gas. In either case, the control locks out.
Cooling start-up
Prestart check list
About this task:
After installation has been completed:
1. Check the electrical supply voltage being
supplied. Be sure that it is the same as listed
on the unit nameplate.
2. Set the room thermostat to the off position.
3. Turn unit electrical power on.
4. Set the room thermostat fan switch to on.
5. Check indoor blower rotation.
If blower rotation is in the wrong direction,
refer to
6. Check blower drive belt tension.
7. Check the unit supply air (CFM).
8. Measure evaporator fan motor's amp draw.
9. Set the room thermostat fan switch to off.
10. Turn unit electrical power off.
Cooling operating instructions
1. Turn unit electrical power on.
2. Set the room thermostat setting to lower than
the room temperature.
3. First stage compressors will energize after the
built-in time delay (five minutes).
Installation Manual ZL Series 7.5- 12.5 Ton 60 Hertz R-410A
Johnson Controls Ducted Systems
Blower phasing.
Note: Prior to each cooling season, the
crankcase heaters where equipment
must be energized at least 10 hours
before the system is put into operation.
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